Comparative effect of orthosis design on functional performance

Biomaterial-Based Regenerative Strategies for Volumetric Muscle Loss: Challenges and Solutions

Significance: Volumetric muscle loss (VML) is caused by the loss of significant amounts of skeletal muscle tissue. VML cannot be repaired by intrinsic regenerative processes, resulting in permanent loss of muscle function and disability. Current rehabilitative-focused treatment strategies lack efficacy and do not restore muscle function, indicating the need for the development of effective regenerative strategies. Recent Advances: Recent developments implicate biomaterial-based approaches for promoting muscle repair and functional restoration post-VML. Specifically, bioscaffolds transplanted in the injury site have been utilized to mimic endogenous cues of the ablated tissue to promote myogenic pathways, increase neo-myofiber synthesis, and ultimately restore contractile function to the injured unit. Critical Issues: Despite the development and preclinical testing of various biomaterial-based regenerative strategies, effective therapies for patients are not available. The unique challenges posed for biomaterial-based treatments of VML injuries, including its scalability and clinical applicability beyond small-animal models, impede progress. Furthermore, production of tissue-engineered constructs is technically demanding, with reproducibility issues at scale and complexities in achieving vascularization and innervation of large constructs. Future Directions: Biomaterial-based regenerative strategies designed to comprehensively address the pathophysiology of VML are needed. Considerations for clinical translation, including scalability and regulatory compliance, should also be considered when developing such strategies. In addition, an integrated approach that combines regenerative and rehabilitative strategies is essential for ensuring functional improvement.

The effect of carbon fiber custom dynamic orthosis type on kinematics and kinetics of lower extremity joints in individuals with lower limb traumatic injuries

BACKGROUND

Carbon fiber custom dynamic orthoses have been used to improve gait mechanics after lower limb trauma in military service members, with the goal of restoring function and improving outcomes. However, the effects of commercially available carbon fiber orthoses available to civilians on lower extremity joint kinetics and kinematics are poorly understood.

RESEARCH QUESTION

The aim of this study was to examine the effect of two commercially available orthoses on lower extremity kinematics and kinetics in individuals with lower limb trauma.

METHODS

A total of 23 participants with a lower extremity traumatic injury underwent gait analysis while walking without an orthosis, and while wearing a monolithic carbon fiber orthosis or while wearing a modular carbon fiber orthosis, in a randomized order. Study participants accommodated to each orthosis for three months prior to testing. Joint kinematics and kinetics at the ankle, knee, and hip joints, and ground reaction forces were assessed.

RESULTS

The two study orthoses significantly reduced ankle motion compared to no orthosis, with large effect sizes observed. Peak plantarflexor moment was greater with the modular orthosis compared to the monolithic orthosis. Ankle push-off power did not differ between orthoses but was significantly reduced relative to no orthosis. Push-off power with the study orthoses was over 25% greater as compared to previous studies with military orthoses. Peak loading response power generation at the knee was greater with the monolithic orthosis as compared to the modular orthosis. The kinematics and kinetics at the hip did not differ between orthoses.

SIGNIFICANCE

Orthoses commonly used in civilian settings to treat limb trauma primarily alter joint kinematics and kinetics at the ankle, in a manner consistent with orthoses used in the military. Additionally, despite the apparent large differences in the designs of the two study orthoses, between-orthosis differences on gait mechanics were limited.

Prediction of the optimal ankle foot-orthosis stiffness based on the peak ankle moment during walking in neuromuscular disorders

PURPOSE

To maximize treatment outcomes with ankle-foot orthosis (AFO) in individuals with plantarflexor weakness, the AFO stiffness needs to be individualized. Peak ankle moment during walking may be used to predict the optimal stiffness. (1) Assess the effects of AFO stiffness on ankle moment, AFO-generated moment, and muscle-generated moment; (2) evaluate the accuracy of predicting optimal AFO stiffness using peak ankle moment during walking without AFO.

MATERIAL AND METHODS

A retrospective analysis was conducted on 18 individuals with neuromuscular disorders with reduced ankle moments during shoes-only walking. AFO stiffness was experimentally optimized to minimize energy cost. Using repeated measures ANOVA we evaluated the effects of AFO stiffness on ankle moment parameters.

RESULTS

A quadratic relationship between AFO stiffness and net ankle moment (p < 0.001), a positive linear relationship with AFO-generated moment (p < 0.001), and a negative linear relationship with muscle-generated moment (p < 0.001) was found. The predicted optimal AFO stiffness, based on the difference between the healthy peak ankle moment (1.2 Nm/kg) and moment without AFO, differed on average 0.53 ± 0.46 Nm/degree (13.7%) from the experimentally optimized stiffness.

CONCLUSIONS

Predicting AFO stiffness based on peak ankle moment during shoes-only walking is a promising method for determining optimal stiffness or guidance of experimental optimization.

Ankle-foot orthoses for improving walking in adults with calf muscle weakness due to neuromuscular disorders

BACKGROUND

Calf muscle weakness is a common symptom in slowly progressive neuromuscular disorders that lead to walking problems like instability and increased walking effort. The mainstay of treatment to improve walking in this population is the provision of ankle-foot-orthoses (AFOs). Since we are not aware of an up-to-date and complete overview of the effects of AFOs used for calf muscle weakness in slowly progressive neuromuscular disorders, we reviewed the evidence for the effectiveness of AFOs to improve walking in this patient group, in order to support clinical decision-making.

OBJECTIVES

To review the evidence for the effects of ankle-foot orthoses (AFOs) for improving walking in adults with calf muscle weakness due to slowly progressive neuromuscular disorders.

SEARCH METHODS

On 10 February 2023, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, Embase, MEDLINE, ClinicalTrials.gov, and WHO ICTRP.

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs), including randomised cross-over studies and quasi-RCTs, and non-randomised studies (NRSs) that examined the effects of AFO interventions compared with shoes-only walking in adults with calf muscle weakness due to neuromuscular disorders.

DATA COLLECTION AND ANALYSIS

We used the methodological procedures described in the Cochrane Handbook for Systematic Reviews of Interventions. We summarised findings for the primary outcome (objectively measured walking effort, assessed as walking energy cost) and secondary outcomes (perceived walking effort, physical mobility, gait parameters, AFO use, satisfaction with the AFO, and adverse events). We grouped results according to the type of AFO material and synthesised them in meta-analysis where possible. We used the GRADE approach to rate the certainty of the evidence.

MAIN RESULTS

We included four randomised cross-over studies and six NRSs with 186 participants in total (the smallest study had 8 participants and the largest had 37). All studies were designed as self-controlled studies and examined the effects of custom-made and/or prefabricated AFOs. The AFOs were made of carbon (5 studies), polypropylene (5 studies), silicone (1 study), metal (1 study), elastic materials (2 studies), or leather combined with other materials (1 study). Outcome measures with AFOs were assessed during a single session (in some studies, people already used the study AFO in daily life), when the AFO was delivered, or at three-week or three-month follow-up. We judged one study to be at moderate risk of bias, and nine studies to be at high or serious risk of bias, primarily due to bias arising from period and carryover effects, selection bias, the inability to blind participants and assessors, missing data, and selective reporting. We found that carbon AFOs may reduce walking energy cost (mean difference (MD) -0.86 J/kg/m, 95% confidence interval (CI) -1.33 to -0.39; 2 studies, 45 participants; low-certainty evidence), and may increase walking speed (MD 0.19 m/s, 95% CI 0.11 to 0.27; 4 studies, 71 participants; low-certainty evidence) compared to shoes-only walking. We found that leather AFOs may increase walking speed (MD 0.25 m/s, 95% CI 0.07 to 0.43; 1 study, 11 participants; low-certainty evidence). Little or no effect on walking speed was found with polypropylene AFOs (MD 0.00 m/s, 95% CI -0.11 to 0.11; 2 studies, 25 participants; low-certainty evidence) and elastic AFOs (MD 0.03 m/s, 95% CI -0.12 to 0.18; 1 study, 14 participants; low-certainty evidence). Carbon AFOs may also enhance satisfaction while walking (1 study, 16 participants; low-certainty evidence). We were unable to draw conclusions about perceived walking effort (one study, 8 participants), balance (two studies, 21 participants), and AFO use (two studies, 51 participants), as the evidence is very uncertain. Finally, two studies (45 participants) reported on adverse events (low-certainty evidence).

AUTHORS' CONCLUSIONS

The available evidence for ankle-foot orthoses (AFOs) to improve walking in adults with calf muscle weakness comes from a limited number of small studies with heterogeneity in intervention characteristics and outcome assessment, and is of low to very low certainty. The evidence suggests that carbon AFOs may reduce walking energy cost (effort), increase walking speed, and enhance satisfaction, and leather AFOs may increase walking speed, while polypropylene and elastic AFOs may make little or no difference to walking speed. We are unable to draw conclusions about the effects of AFOs on perceived walking effort, balance, and use. Nor can we draw conclusions about adverse effects of using AFOs. The variety in the findings for AFOs made of different materials suggests further investigation is warranted to explore how different AFO materials impact walking improvement in people with calf muscle weakness due to slowly progressive neuromuscular disorders.

Influence of custom dynamic orthoses on tibiotalar joint reaction force and contact stress: A cadaveric study

Post-traumatic osteoarthritis (PTOA) often develops following tibial pilon fractures. Evidence suggesting PTOA development is driven by elevated articular contact stress from residual malreduction has led surgeons to strive for precise articular reduction, typically at the cost of extended operative time. Post-operative bracing using carbon fiber custom dynamic orthoses (CDOs) offers another means to decrease tibiotalar joint reaction force (JRF) and contact stress. The purpose of this cadaveric study was to measure how CDO stiffness influences ankle JRF and contact stress over the stance phase of gait. A servohydraulic load frame was used to test five cadaver ankles, with axial loading (240-330 N) and pneumatic actuation of the Achilles tendon (50-436 N) serving to quasi-statically model multiple points in the stance phase of gait. Three CDO rotational stiffness conditions were tested: (1) No CDO-0 Nm/deg, (2) low stiffness CDO-1.8 Nm/deg, and (3) moderate stiffness CDO-2.3 Nm/deg. JRF and contact stresses were measured using a piezoresistive pressure sensor inserted into the tibiotalar joint. An insole plantar pressure sensor placed between the cadaveric foot and CDO footplate measured limb/device interactions via the plantar center of pressure (COP). As limb loading progressed through stance, the plantar COP progressed from hindfoot to forefoot, as it would in normal gait. Both CDOs demonstrated decreases in JRF, reaching as high as 32% for the low CDO and 26% for the moderate CDO, with associated decreases in contact stress. This suggests that post-operative bracing could lessen PTOA risk after pilon fractures.

Ankle osteoarthritis: Toward new understanding and opportunities for prevention and intervention

The ankle infrequently develops primary osteoarthritis (OA), especially when compared to the hip and the knee. Ankle OA instead generally develops only after trauma. The consequences of end-stage ankle OA can nonetheless be extremely debilitating, with impairment comparable to that of end-stage kidney disease or congestive heart failure. Disconcertingly, evidence suggests that ankle OA can develop more often than is generally appreciated after even low-energy rotational ankle fractures and chronic instability associated with recurrent ankle sprains, albeit at a slower rate than after more severe trauma. The mechanisms whereby ankle OA develops after trauma are poorly understood, but mechanical factors are implicated. A better understanding of the prevalence and mechanical etiology of post-traumatic ankle OA can lead to better prevention and mitigation. New surgical and conservative interventions, including improved ligamentous repair strategies and custom carbon fiber bracing, hold promise for advancing treatment that may prevent residual ankle instability and the development of ankle OA. Studies are needed to fill in key knowledge gaps here related to etiology so that the interventions can target key factors. New technologies, including weight bearing CT and biplane fluoroscopy, offer fresh opportunities to better understand the relationships between trauma, ankle alignment, residual ankle instability, OA development, and foot/ankle function. This paper begins by reviewing the epidemiology of post-traumatic ankle OA, presents evidence suggesting that new treatment options might be successful at preventing ankle OA, and then highlights recent technical advances in understanding of the origins of ankle OA to identify directions for future research.

Effects of 3D-printed ankle-foot orthoses on gait: a systematic review

This systematic review aimed to explore comprehensive evidence on the efficacy of the 3D-printed ankle-foot orthoses (AFOs) on gait parameters in individuals with neuromuscular and/or musculoskeletal ankle impairments. Electronic databases including PubMed, Scopus, Web of Science, Embase, ProQuest, Cochrane, and EBSCOhost were searched from inception to August 2023. Ten studies that had participants with ankle impairments, as a result of stroke, cerebral palsy, mechanical trauma, muscle weakness, or Charcot-Marie-Tooth disease, investigated the immediate effects of the 3D-printed AFOs on gait parameters were included. Methodological rigor was evaluated using the modified Downs & Black index. The gait parameters included lower extremity joint angles, moments, and work/power, plantar pressures, spatiotemporal measures, and patient satisfaction were improved with the 3D-printed AFOs when compared to the no-AFO (i.e. barefoot, or shoe-only) conditions. 3D-printed AFOs revealed similar functional efficacy as conventional AFOs. Notably, the level of patient satisfaction regarding fitting and comfort was higher with the 3D-printed AFOs. Although the study on the effects of the 3D-printed AFOs are limited, emerging evidence indicates their effectiveness in improving gait biomechanics and functions. To further confirm their effects, rigorous randomized control studies with larger sample sizes and longer follow-ups on the effects are warranted in the future.

The effect of carbon fiber custom dynamic orthosis use and design on center of pressure progression and perceived smoothness in individuals with lower limb trauma

BACKGROUND

Carbon-fiber custom dynamic orthoses are used to improve gait and limb function following lower limb trauma in specialty centers. However, the effects of commercially available orthoses on center of pressure progression and patient perception of orthosis smoothness during walking are poorly understood.

METHODS

In total, 16 participants with a unilateral lower extremity traumatic injury underwent gait analysis when walking without an orthosis, and while wearing monolithic and modular devices, in a randomized order. Device alignment, stiffness, participant rating of perceived device smoothness, center of pressure velocity, and ankle zero moment crossing were assessed.

FINDINGS

The modular device was approximately twice as stiff as the monolithic device. Alignment, smoothness ratings, peak magnitude of center of pressure velocity, and zero moment crossing were not different between study devices. The time to peak center of pressure velocity occurred significantly later for the modular device compared to the monolithic and no orthosis conditions, with large effect sizes observed.

INTERPRETATION

Commercially available orthoses commonly used to treat limb trauma affect the timing of center of pressure progression relative to walking without an orthosis. Despite multiple design differences, monolithic and modular orthoses included in this study did not differ with respect to other measures of center of pressure progression. Perceived smoothness ratings were approximately 40% greater with the study orthoses as compared to previous studies in specialty centers, which may be due to a more gradual center of pressure progression, as indicted by lower peak magnitude of center of pressure velocity with both study orthoses.

A patient-centered 'test-drive' strategy for ankle-foot orthosis prescription: Protocol for a randomized participant-blinded trial

BACKGROUND

Ankle-foot orthoses (AFOs) are commonly used to overcome mobility limitations related to lower limb musculoskeletal injury. Despite a multitude of AFOs to choose from, there is scant evidence to guide AFO prescription and limited opportunities for AFO users to provide experiential input during the process. To address these limitations in the current prescription process, this study evaluates a novel, user-centered and personalized 'test-drive' strategy using a robotic exoskeleton ('AFO emulator') to emulate commercial AFO mechanical properties (i.e., stiffness). The study will determine if brief, in-lab trials (with emulated or actual AFOs) can predict longer term preference, satisfaction, and mobility outcomes after community trials (with the actual AFOs). Secondarily, it will compare the in-lab experience of walking between actual vs. emulated AFOs.

METHODS AND ANALYSIS

In this participant-blinded, randomized crossover study we will recruit up to fifty-eight individuals with lower limb musculoskeletal injuries who currently use an AFO. Participants will walk on a treadmill with three actual AFOs and corresponding emulated AFOs for the "in-lab" assessments. For the community trial assessment, participants will wear each of the actual AFOs for a two-week period during activities of daily living. Performance-based and user-reported measures of preference and mobility will be compared between short- and long-term trials (i.e., in-lab vs. two-week community trials), and between in-lab trials (emulated vs. actual AFOs).

TRIAL REGISTRATION

The study was prospectively registered at www.clininicaltrials.gov (Clinical Trials Study ID: NCT06113159). Date: November 1st 2023. https://classic.clinicaltrials.gov/ct2/show/NCT06113159.

The Effect of a New Generation of Ankle Foot Orthoses on Sloped Walking in Children with Hemiplegia Using the Gait Real Time Analysis Interactive Lab (GRAIL)

Cerebral palsy poses challenges in walking, necessitating ankle foot orthoses (AFOs) for stability. Gait analysis, particularly on slopes, is crucial for effective AFO assessment. The study aimed to compare the performance of commercially available AFOs with a new sports-specific AFO in children with hemiplegic cerebral palsy and to assess the effects of varying slopes on gait. Eighteen participants, aged 6-11, with hemiplegia, underwent gait analysis using GRAIL technology. Two AFO types were tested on slopes (uphill +10 deg, downhill -5 deg, level-ground). Kinematic, kinetic, and spatiotemporal parameters were analyzed. The new AFO contributed to significant changes in ankle dorsi-plantar-flexion, foot progression, and trunk and hip rotation during downhill walking. Additionally, the new AFO had varied effects on spatiotemporal gait parameters, with an increased stride length during downhill walking. Slope variations significantly influenced the kinematics and kinetics. This study provides valuable insights into AFO effectiveness and the impact of slopes on gait in hemiplegic cerebral palsy. The findings underscore the need for personalized interventions, considering environmental factors, and enhancing clinical and research approaches for improving mobility in cerebral palsy.

Lower Extremity Assistive Devices (LEADs): A Contemporary Literature Review

Lower extremity ambulatory assistive devices (LEADs) are important augments that provide mobility and stability when weightbearing is restricted in the setting of injury, surgery, or balance disorders. In order to optimize patient safety and function when prescribing these devices, it is essential for the orthopaedic surgeon to have a firm understanding of their specific indications, proper fitting, energy demand, biomechanical advantages, and potential complications. Comprehension of normal gait cadence, identification of the functional deficit present and knowledge of available options will assist in safely prescribing the proper device. Over the last decade, newer alternatives to traditional LEADs (canes, crutches, walkers) have become available, including the rolling knee scooter and hands-free single crutch. These have been developed to improve mobility and independence; however, it is necessary to appreciate their limitations when prescribing them to patients. This review will provide an update on normal and pathologic gait biomechanics as well as the most common types of LEADs currently available to the orthopaedic surgeon, their indications, important considerations, proper fitting, associated energy expenditure, and complications.

Electrically stimulated eccentric contraction training enhances muscle mass, function, and size following volumetric muscle loss

Volumetric muscle loss (VML) overwhelms muscle's innate capacity for repair and can lead to permanent disability. The standard of care for VML injuries includes physical therapy, which can improve muscle function. The objective of this study was to develop and evaluate a rehabilitative therapy using electrically stimulated eccentric contraction training (EST) and determine the structural, biomolecular, and functional response of the VML-injured muscle. This study implemented EST using three different frequencies (50, 100, and 150 Hz) in VML-injured rats starting at 2 weeks postinjury. Four weeks of EST at 150 Hz showed a progressive increase in eccentric torque with an improvement in muscle mass (~39%), myofiber cross-sectional area, and peak isometric torque (~37.5%) relative to the untrained VML-injured sham group. EST at 150 Hz group also increased the number of large type 2B fibers (>5000 µm2 ). Elevated gene expression of markers associated with angiogenesis, myogenesis, neurogenesis, and an anti-inflammatory response was also observed. These results suggest that VML-injured muscles can respond and adapt to eccentric loading. The results of this study may aid in developing physical therapy regimens for traumatized muscles.

Short-term effect of a carbon fiber custom dynamic orthosis and integrated rehabilitation on self-reported physical function, pain, speed, and agility in civilians

BACKGROUND

Ankle-foot orthoses (AFOs) are widely used to restore mobility and reduce pain in individuals with lower extremity pain and disability. The use of a carbon fiber custom dynamic orthosis (CDO) with integrated physical training and psychosocial intervention has been shown to improve outcomes in a military setting, but civilian data are limited.

OBJECTIVES

To use existing clinical data to evaluate the initial effectiveness of an integrated CDO and rehabilitative program and identify baseline characteristics that impact patient response to the intervention.

STUDY DESIGN

Retrospective cohort.

METHODS

Records of 131 adult patients who received a CDO and device specific training were reviewed. Patient-reported measures of pain and lower extremity function and physical measurements of walking and agility were extracted at baseline and on training completion.

RESULTS

A majority of patients reported improved or greatly improved physical function (92%), maximum pain (69%), and typical pain (55%) and experienced improved or greatly improved walking speed (92%) and agility (52%) irrespective of age and sex. Regression models for examining short-term improvement in pain and physical function accounted for 52% (p < 0.001) and 26% (p < 0.001) of the outcome variance, respectively. Improvement in typical pain was influenced by baseline typical and maximum pain, and functional improvement was influenced by sex and baseline physical function.

CONCLUSIONS

Most patients (92.4%) reported a positive initial outcome after intervention as measured using patient-reported and objective measures.

Development and initial validation of the Orthotic Patient-Reported Outcomes-Mobility (OPRO-M): An item bank for evaluating mobility of people who use lower-limb orthoses

Lower limb orthoses (LLOs) are externally-applied leg braces that are designed to improve or maintain mobility in people with a variety of health conditions that affect lower limb function. Clinicians and researchers are therefore often motivated to measure LLO users' mobility to select or assess the effectiveness of these devices. Patient-reported outcome measures (PROMs) can provide insights into important aspects of a LLO user's mobility for these purposes. However, few PROMs are available to measure mobility of LLO users. Those few that exist have issues that may limit their clinical or scientific utility. The objective of this study was to create a population-specific item bank for measuring mobility of LLO users. Previously-developed candidate items were administered in a cross-sectional study to a large national sample of LLO users. Responses from study participants (n = 1036) were calibrated to a graded response statistical model using Item Response Theory methods. A set of 39 items was found to be unidimensional, locally independent, and function without bias due to characteristics unrelated to mobility. The set of final calibrated items, termed the Orthotic Patient-Reported Outcomes-Mobility (OPRO-M) item bank, was evaluated for initial evidence of convergent, divergent, and known groups construct validity. OPRO-M was strongly correlated with existing PROMs designed to measure aspects of physical function. Conversely, OPRO-M was weakly correlated with PROMs that measured unrelated constructs, like sleep disturbance and depression. OPRO-M also showed an ability to differentiate groups with expected mobility differences. Two fixed-length short forms were created from the OPRO-M item bank. Items on the short forms were selected based on statistical and clinical criteria. Collectively, results from this study indicate that OPRO-M can effectively measure mobility of LLO users, and OPRO-M short forms can now be recommended for use in routine clinical practice and research studies.

Carbon fiber ankle-foot orthoses in impaired populations: A systematic review

BACKGROUND

Carbon fiber is increasingly being used in ankle-foot orthoses (AFOs). Orthotic devices and carbon fiber-containing devices have been shown to reduce pain and improve function in multiple patient populations. Although the number of publications and interest in carbon fiber AFOs is growing, a systematic evaluation of their effects is lacking.

OBJECTIVES

To characterize the effects of carbon fiber AFOs in impaired individuals.

STUDY DESIGN

Qualitative systematic review.

METHODS

Systematic searches in PubMed, Embase, CINAHL, and Cochrane Library were completed in July 2020. The results were deduplicated, screened, and assessed for quality by independent reviewers. Articles were excluded if they had nonhuman subjects, only healthy subjects, or included active control systems, motors, or other power sources.

RESULTS

Seventy-eight articles were included in the qualitative synthesis. Most articles were of low to moderate methodological quality. Five commonly used devices were identified: the Intrepid Dynamic Exoskeletal Orthosis, ToeOff, WalkOn, Neuro Swing, and Chignon. The devices have unique designs and are associated with specific populations. The Intrepid Dynamic Exoskeletal Orthosis was used in individuals with lower-limb trauma, the Neuro Swing and ToeOff in individuals with neurological disorders, the Chignon in individuals with hemiplegia and stroke, and the WalkOn in people with hemiplegia and cerebral palsy. Each device produced favorable outcomes in their respective populations of interest, such as increased walking speed, reduced pain, or improved balance.

CONCLUSIONS

The mechanical characteristics and designs of carbon fiber AFOs improve outcomes in the populations in which they are most studied. Future literature should diligently report patient population, device used, and fitting procedures.

Novel Metrics for Assessing Mobility During Ground-Standing Transitions

INTRODUCTION

Transitioning between the ground and standing is a required activity for many professions including skilled trades, law enforcement, and military service. However, available assessments are limited and focus primarily on quality of movement. Thus, we developed two novel assessments of functional mobility specific for ground-to-standing transitions: Stand-Prone-Standx2 (SPS2) and Stand-Kneel-Standx2 (SKS2-L/R) tests. The purpose of this study was to determine the psychometrics of these two new measures in able-bodied (AB) service members and in service members with unilateral lower extremity injury (LEI).

MATERIALS AND METHODS

A total of 57 AB service members and 31 service members with a traumatic unilateral LEI wearing a custom carbon-fiber ankle-foot orthosis participated in this study. In total, 36 AB and 18 LEI participants returned for a second session to assess intersession reliability. Intraclass correlation coefficients were calculated for intersession and inter-rater comparisons (two-way random model for consistency and single measure). Additionally, performance was compared between legs and groups.

RESULTS

The SPS2 and SKS2 assessments demonstrated excellent inter-rater and intersession reliability in both the AB and LEI groups with all intraclass correlation coefficient values greater than 0.8. Further, the tests were responsive to deficits associated with LEI, with the LEI group having significantly longer times on all assessments compared to the AB group.

CONCLUSIONS

The SPS2 and SKS2 performance measures were found to have excellent inter-rater and intersession reliability in both AB participants and participants with LEI. Further, participants with LEI performed significantly slower than the AB participants. Excellent reliability and responsiveness to deficits associated with LEI support the use of the SPS2 and SKS2 to assess mobility in individuals with LEI. Transitions between the ground and standing occur in many occupational and daily tasks. These reliable performance measures that assess ground-to-stand transitions can be applied widely, in many populations beyond highly functioning service members with LEI.

Passive Dynamic Ankle Foot Orthoses Use in Civilian Patients with Arthritic Conditions of the Foot and Ankle

Background

Nonsurgical interventions such as bracing with ankle foot orthoses (AFOs) aim to assist, restore, and redirect weightbearing forces to address difficulty with mobilization. We identified a custom carbon fiber passive dynamic ankle foot orthosis (PDAFO) that was designed to meet the needs of military combat veterans. We sought to evaluate the off-loading properties of one model of PDAFO (ExoSym) in a civilian population.

Methods

Civilian patients 18 years or older were prescribed a PDAFO by a single surgeon. Pedobarographic data were obtained using the Tekscan F-Scan system. With the insole, participants were instructed to walk at a self-selected pace along a 20 m walkway under 3 conditions: (1) insole placed in between the brace and foot (over); (2) insole placed between the brace and insole of the shoe (under); (3) without the brace, the insole was placed in between the foot and insole of the shoe in both limbs (without).For assessment, forefoot and heel areas were evaluated with respect to maximal force, force*time integral (FTI), maximal contact area, maximal contact pressure, pressure*time integral (PTI), center of force (COF) excursion.

Results

Six patients with arthritic foot and ankle conditions completed pedobarographic assessment for analysis. The brace reduced forefoot maximal force and contact pressures by 66% and 49%, respectively (538 ± 236 to 185 ± 130 N [P < .001], and 99 ± 38 to 50 ± 24 P < .002). Additionally, participants were observed to load the forefoot portion of the brace with double the maximum contact pressures compared to the unbraced foot (204 ± 57 to 99 ± 38 kPa, P < .001).

Conclusion

The results of this study showed that the PDAFO unloaded substantial force and pressure experienced by the forefoot. Participants loaded the brace to a greater extent than when going unbraced. ADAFO can provide measurable pressure relief for patients with arthritic conditions.

Level of Evidence

Level IV, case series.

A Novel Quick Release Mechanism for Ankle Foot Orthosis Struts

BACKGROUND

A posterior dynamic element ankle-foot orthosis (PDEAFO) uses a stiff carbon fibre strut to store and release energy during various mobility tasks, with the strut securely attached to the foot and shank-cuff sections. A design that allows the user to swap struts for specific activities could improve mobility by varying PDEAFO stiffness, but current approaches where bolts securely connect the strut to the orthosis make quick strut swapping time-consuming and impractical.

OBJECTIVES

Design a novel quick release AFO (QRAFO) that can enable daily living strut-swapping and thereby enable better ankle biomechanics for the person's chosen activity.

METHODOLOGY

The novel QRAFO enables device stiffness changes through a quick release mechanism that includes a quick-release key, weight-bearing pin, receptacle anchor, and immobilization pin. A prototype was modelled and simulated with SolidWorks. Mechanical tests were performed with an Instron 4482 machine to evaluate quick release mechanism strength with running and 20° slope downhill walking loads. Quick release efficiency was then evaluated via two quick release functional tests, with four participants wearing a 3D printed QRAFO.

FINDINGS

Simulated stress on the weight bearing pin, anchor, and surrounding carbon fibre structure under running and downhill walking loads did not exceed the yielding stress. Mechanical tests verified the simulation results. Four participants successfully swapped the strut within 25.01 ± 3.66 seconds, outperforming the 60.48 ± 10.88 seconds result for the hand-tightened bolted strut. A learning evaluation with one participant showed that, after approximately 30 swapping iterations, swap time was consistently below 10 seconds.

CONCLUSION

The quick release mechanism accommodated running and slope walking loads, and allowed easy and fast strut removal and attachment, greatly reducing strut swap time compared to screw-anchor connections. Overall, the novel quick release AFO improved strut-swapping time without sacrificing device strength, thereby enabling people to use the most appropriate AFO stiffness for their current activity and hence improve mobility and quality of life.

Common fall-risk indicators are not associated with fall prevalence in a high-functioning military population with lower limb trauma

BACKGROUND

Persons with lower limb trauma are at high risk for falls. Although there is a wide range of measures used to assess stability and fall-risk that include performance measures, temporal-spatial gait parameters, and nonlinear dynamic stability calculations, these measures are typically derived from fall-prone populations, such as older adults. Thus, it is unclear if these commonly used fall-risk indicators are effective at evaluating fall-risk in a younger, higher-functioning population of Service members with lower limb trauma.

METHODS

Twenty-one Service members with lower limb trauma completed a battery of fall-risk assessments that included performance measures (e.g., four-square-step-test), and gait parameters (e.g., step width, step length, step time) and dynamic stability measures (e.g., local divergence exponents) during 10 min of treadmill walking. Participants also reported the number of stumbles and falls over the previous 4 weeks. Negative Binomial and Quasibinomial Regressions were used to evaluate the strength of associations between fall-risk indicators and self-reported falls.

FINDING

Participants reported on average stumbling 6(4) times and falling 2(3) times in the previous 4 weeks. At least one fall was reported by 62% of the participants. None of the fall-risk indicators were significantly associated with fall prevalence in this population of Service members with lower limb trauma (p > 0.1).

INTERPRETATION

Despite the high number of reported falls in this young active population, none of the fall-risk indicators investigated effectively captured and quantified the fall-risk. Further research is needed to identify appropriate fall-risk assessments for young, high-functioning individuals with lower limb trauma.

Users' Perceptions About Lower Extremity Orthotic Devices: A Systematic Review

OBJECTIVE

To systematically review perceptions from adults, children, and caregivers in scientific and open sources to determine how well lower extremity orthotic devices (LEODs) meet users' functional, expressive, aesthetic, and accessibility (FEA2) needs.

DATA SOURCES

Scientific source searches were conducted in the National Library of Medicine (PubMed/MEDLINE) and Web of Science; open source searches were conducted in Google Search Engine in April 2020.

STUDY SELECTION

Inclusion criteria were reporting of users' perceptions about a LEOD, experimental or observational study design, including qualitative studies, and full text in English. Studies were excluded if the device only provided compression or perception data could not be extracted. One hundred seventy three scientific sources of 3440 screened were included (total of 1108 perceptions); 36 open sources of 150 screened were included (total of 508 perceptions).

DATA EXTRACTION

Users' perceptions were independently coded by 2 trained, reliable coders.

DATA SYNTHESIS

Across both source types, there were more perceptions about functional needs, and perceptions were more likely to be positive related to functional than expressive, aesthetic, or accessibility needs. Perceptions about expression, aesthetics, and accessibility were more frequently reported and more negative in open vs scientific sources. Users' perceptions varied depending on users' diagnosis and device type.

CONCLUSIONS

There is significant room for improvement in how LEODs meet users' FEA2 needs, even in the area of function, which is often the primary focus when designing rehabilitation devices. Satisfaction with LEODs may be improved by addressing users' unmet needs. Individuals often choose not to use prescribed LEODs even when LEODs improve their function. This systematic review identifies needs for LEODs that are most important to users and highlights how well existing LEODs address those needs. Attention to these needs in the design, prescription, and implementation of LEODs may increase device utilization.

A modified passive-dynamic ankle-foot orthosis: can it prevent amputation and arthrodesis in patients with ankle-foot trauma?

INTRODUCTION

High-energy lower extremity trauma (HELET) may cause severe damage within the foot-ankle complex. Occasionally, arthrodesis or amputation are the only remaining options to increase activity levels. The modified passive dynamic ankle-foot orthosis (PDAFO) may prove to be a nonsurgical alternative. This study evaluated the effect of a modified PDAFO with a 6-week training program on pain and performance in patients after HELET.

MATERIALS AND METHODS

A retrospective cohort study was conducted on seventeen patients who considered an arthrodesis or an amputation after HELET. In an attempt to avoid surgery, the modified PDAFO with a 6-week training program was provided. Pain scores was measured with the Numeric Rating Scale and administered at the start of testing, immediately after the two performance tests and at the end of the day of testing. Performance was evaluated with the 6-min walk test (6MWT) and the Comprehensive high-level activity mobility predictor (CHAMP).

RESULTS

A significant pain reduction was achieved after the treatment procedure. At the start of the test days (p = 0.002), after the 6MWT (p = 0.001), after the CHAMP (p < 0.001) and at the end of the day (p < 0.001). In addition, a significant improvement on performance was observed in the 6MWT (p < 0.001) and the CHAMP (p = 0.01). None of the patients considered a surgical intervention anymore.

CONCLUSIONS

Patients after HELET show a decrease in pain and an improvement in performance after a 6-week training program with modified PD-AFO. The results suggest that the modified PDAFO is an effective alternative for a surgical approach.

Comparison of Existing Methods for Characterizing Bi-Linear Natural Ankle Quasi-Stiffness

Natural ankle quasi-stiffness (NAS) is a mechanical property of the ankle joint during motion. NAS has been historically calculated as the average slope (linear regression) of the net ankle moment vs. ankle angle during discrete phases of stance. However, recent work has shown that NAS is nonlinear during stance. Specifically, during the loading phase (~10-60% of stance), plantarflexion moment increases at an accelerating rate compared to dorsiflexion angle. Updated models have been developed to better capture this inherent nonlinearity. One type of model is called bi-linear NAS (BL-NAS) divides the loading phase of stance into two sub-phases, called early loading (EL) and late loading (LL) NAS. Two papers, written by Crenna & Frigo in 2011 and Shamaei et al. in 2013, outline different BL-NAS models. Both models fit measured data better (lower RMSE) than standard single linear NAS (SL-NAS) models, but have not been widely adopted, possibly because of methodological discrepancies and lack of applicability to physical devices at the time. This paper compares these existing BL-NAS models and translate those findings to possible orthotic device designs. Results showed that both BL-NAS models had lower RMSE than SL-NAS, EL-NAS was not significantly different across walking speeds, and LL-NAS increased significantly at faster walking speeds. These improved NAS models better approximate natural human movement than commonly used SL-NAS models, and provide a basis to design ankle-foot devices with multiple stiffness properties to emulate and facilitate natural human motion.

Characterizing the Mechanical Stiffness of Passive-Dynamic Ankle-Foot Orthosis Struts

People with lower limb impairment can participate in activities such as running with the use of a passive-dynamic ankle-foot orthosis (PD-AFO). Specifically, the Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a PD-AFO design that includes a carbon-fiber strut, which attaches posteriorly to a custom-fabricated tibial cuff and foot plate and acts in parallel with the impaired biological ankle joint to control sagittal and mediolateral motion, while allowing elastic energy storage and return during the stance phase of running. The strut stiffness affects the extent to which the orthosis keeps the impaired biological ankle in a neutral position by controling sagittal and mediolateral motion. The struts are currently manufactured to a thickness that corresponds with one of five stiffness categories (1 = least stiff, 5 = most stiff) and are prescribed to patients based on their body mass and activity level. However, the stiffness values of IDEO carbon-fiber struts have not been systematically determined, and these values can inform dynamic function and biomimetic PD-AFO prescription and design. The PD-AFO strut primarily deflects in the anterior direction (ankle dorsiflexion), and resists deflection in the posterior direction (ankle plantarflexion) during the stance phase of running. Thus, we constructed a custom apparatus and measured strut stiffness for 0.18 radians (10°) of anterior deflection and 0.09 radians (5°) of posterior deflection. We measured the applied moment and strut deflection to compute angular stiffness, the quotient of moment and angle. The strut moment-angle curves for anterior and posterior deflection were well characterized by a linear relationship. The strut stiffness values for categories 1–5 at 0.18 radians (10°) of anterior deflection were 0.73–1.74 kN·m/rad and at 0.09 radians (5°) of posterior deflection were 0.86–2.73 kN·m/rad. Since a PD-AFO strut acts in parallel with the impaired biological ankle, the strut and impaired biological ankle angular stiffness sum to equal total stiffness. Thus, strut stiffness directly affects total ankle joint stiffness, which in turn affects ankle motion and energy storage and return during running. Future research is planned to better understand how use of a running-specific PD-AFO with different strut stiffness affects the biomechanics and metabolic costs of running in people with lower limb impairment.

Laminin-111-Enriched Fibrin Hydrogels Enhance Functional Muscle Regeneration Following Trauma

Volumetric muscle loss (VML) is the surgical or traumatic loss of skeletal muscle, which can cause loss of limb function or permanent disability. VML injuries overwhelms the endogenous regenerative capacity of skeletal muscle and results in poor functional healing outcomes. Currently, there are no approved tissue engineering treatments for VML injuries. In this study, fibrin hydrogels enriched with laminin-111 (LM-111; 50-450 μg/mL) were used for the treatment of VML of the tibialis anterior in a rat model. Treatment with fibrin hydrogel containing 450 μg/mL of LM-111 (FBN450) improved muscle regeneration following VML injury. FBN450 hydrogel treatment increased the relative proportion of contractile to fibrotic tissue as indicated by the myosin: collagen ratio on day 28 post-VML injury. FBN450 hydrogels also enhanced myogenic protein expression and increased the quantity of small to medium size myofibers (500-2000 μm²) as well as innervated myofibers. Improved contractile tissue deposition due to FBN450 hydrogel treatment resulted in a significant improvement (∼60%) in torque production at day 28 postinjury. Taken together, these results suggest that the acellular FBN450 hydrogels provide a promising therapeutic strategy for VML that is worthy of further investigation.

IDEO energy-storing orthosis: Effects on lower extremity function and preservation

INTRODUCTION

The Intrepid Dynamic Exoskeletal Orthosis (IDEO) brace is a custom energy-storing orthosis design meant to improve gait, stability, and function after lower extremity injury or limb salvage. Early studies demonstrated the potential for the IDEO to improve functional performance, in conjunction with its paired return to run (RTR) rehabilitation program, compared to other brace types, and an impressively decreased rate of late amputation. The current study aimed to investigate these functional and revision outcomes from our institution to determine which patients may benefit most from IDEO bracing and what factors of the IDEO design and rehabilitation program are most important for improved outcomes after lower extremity trauma and/or loss of function.

METHODS

We performed a retrospective review of all patients treated with a IDEO style brace at a single military lower extremity trauma referral center between May 2003 and November 2017. We reviewed the medical records for initial diagnosis, post-orthotic rehabilitation program, IDEO use characteristics, pain, change in desire for amputation, and whether patient underwent eventual amputation.

RESULTS

We identified 213 patients with 222 lower extremities treated with IDEO brace. Of these, 76 limbs were treated for combat-related injuries. At one year follow-up, use status could not be determined for 37 extremities (16.7%). Of the 185 limbs with use data available, 116 (61.1%) continued regular brace use, and 37 (15.7%) reported intermittent use. Patients diagnosed with footdrop or weakness were more likely to continue use (OR 2.33, p=0.04), while patients with a previous fusion were less likely to continue use (OR 0.45, p=0.049). Undergoing any dedicated therapy increased chances of continued use (OR 3.37, p<0.001). At final follow-up, 16 patients (7.5%) underwent delayed lower extremity amputations following IDEO treatment. Overall, 27.2% of patients who initially desired amputation eventually underwent amputation despite IDEO brace use. Patients who underwent amputation reported higher pain levels (2 versus 5, p<0.001).

DISCUSSION

In select patients, the IDEO may decrease the desire for delayed amputation and permit higher levels of activity; however, its efficacy appears tied to the rehabilitative regimen, pain levels, and initial diagnosis. These findings should guide post-surgical extremity bracing prescriptions and expectations.

Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population

BACKGROUND

Lower extremity fractures represent a high percentage of reported injuries in the United States military and can devastate a service member's career. A passive dynamic ankle-foot orthosis (PD-AFO) with a specialized rehabilitation program was initially designed to treat military service members after complex battlefield lower extremity injuries, returning a select group of motivated individuals back to running. For high-demand users of the PD-AFO, the spatiotemporal gait parameters, agility, and quality of life is not fully understood with respect to uninjured runners.

QUESTIONS/PURPOSES

Do patients who sustained a lower extremity fracture using a PD-AFO with a specialized rehabilitation program differ from uninjured service members acting as controls, as measured by (1) time-distance and biomechanical parameters associated with running, (2) agility testing (using the Comprehensive High-level Activity Mobility Predictor performance test and Four Square Step Test), and (3) the Short Musculoskeletal Function Assessment score.

METHODS

We conducted a retrospective data analysis of a longitudinally collected data registry of patients using a PD-AFO from 2015 to 2017 at a single institution. The specific study cohort were patients with a unilateral lower extremity fracture who used the PD-AFO for running. Patients had to be fit with a PD-AFO, have completed rehabilitation, and have undergone a three-dimensional (3-D) running analysis at a self-selected speed at the completion of the program. Of the 90 patients who used the PD-AFO for various reasons, 10 male service members with lower extremity fractures who used a PD-AFO for running (median [range] age 29 years [22 to 41], height 1.8 meters [1.7 to 1.9], weight 91.6 kg [70 to 112]) were compared with 15 uninjured male runners in the military (median age 33 years [21 to 42], height 1.8 meters [1.7 to 1.9], weight 81.6 kg [71.2 to 98.9]). The uninjured runners were active-duty service members who voluntarily participated in a gait analysis at their own self-selected running speeds; to meet eligibility for inclusion as an uninjured control, the members had to be fit for full duty without any medical restrictions, and they had to be able to run 5 miles. The controls were then matched to the study group by age, weight, and height. The primary study outcome variables were the running time-distance parameters and frontal and sagittal plane kinematics of the trunk and pelvis during running. The Four Square Step Test, Comprehensive High-level Activity Mobility Predictor scores, and Short Musculoskeletal Function Assessment scores were analyzed for all groups as secondary outcomes. Nonparametric analyses were performed to determine differences between the two groups at p < 0.05.

RESULTS

For the primary outcome, patients with a PD-AFO exhibited no differences compared with uninjured runners in median (range) running velocity (3.9 meters/second [3.4 to 4.2] versus 4.1 meters/second [3.1 to 4.8], median difference 0.2; p = 0.69), cadence (179 steps/minute [169 to 186] versus 173 steps/minute [159 to 191], median difference 5.8; p = 0.43), stride length (2.6 meters [2.4 to 2.9] versus 2.8 meters [2.3 to 3.3], median difference 0.2; p = 0.23), or sagittal plane parameters such as peak pelvic tilt (24° [15° to 33°] versus 22° [14° to 28°], median difference 1.6°; p = 0.43) and trunk forward flexion (16.2° [7.3° to 23°) versus 15.4° [4.2° to 21°), median difference 0.8°; p > 0.99) with the numbers available. For the secondary outcomes, runners with a PD-AFO performed worse in Comprehensive High-level Activity Mobility Predictor performance testing than uninjured runners did, with their four scores demonstrating a median (range) single-limb stance of 35 seconds (32 to 58) versus 60 seconds (60 to 60) (median difference 25 seconds; p < 0.001), t-test result of 15 seconds (13 to 20) versus 13 seconds (10 to 14) (median difference 2 seconds; p < 0.001), and Illinois Agility Test result of 22 seconds (20 to 25) versus 18 seconds (16 to 20) (median difference 4; p < 0.001). Edgren side step test result of 20 meters (16 to 26) versus 24 meters (16 to 29) (median difference 4 meters; p = 0.11) and the Four Square Step Test of 5.5 seconds (4.1 to 7.2) versus 4.2 seconds (3.1 to 7.3) (median difference 1.3 seconds; p = 0.39) were not different between the groups with an effect size of 0.83 and 0.75, respectively.

CONCLUSION

The results of our study demonstrate that service members run with discernible differences in high-level mobility and demonstrate inferior self-reported patient functioning while having no differences in speed and biomechanics compared with their noninjured counterparts with the sample size available. This study is an early report on functional gains of highly motivated service members with major lower extremity injuries who use a PD-AFO and formalized therapy program to run.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Inclusion of a Military-specific, Virtual Reality-based Rehabilitation Intervention Improved Measured Function, but Not Perceived Function, in Individuals with Lower Limb Trauma

INTRODUCTION

Lower extremity injury is common in the military and can lead to instability, pain, and decreased function. Military service also places high physical demands on service members (SMs). Standard treatment interventions often fail to align with these unique demands. Thus, the goal of the study was to evaluate the effectiveness of a military-specific virtual reality-based rehabilitation (VR) intervention supplemental to standard care (SC) in improving military performance in SMs with lower extremity injuries.

MATERIALS AND METHODS

As part of an institutional review board-approved randomized control trial, SMs receiving care at an advanced rehabilitation center were randomized to receive either SC or VR in addition to SC (VR+SC). Participants were evaluated before treatment and ∼3 weeks later using a previously developed and validated military-specific assessment. Perceived improvement in physical function was measured using a Global Rating of Change (GROC) questionnaire. A repeated measures ANOVA was used to evaluate the effects of adding VR on the military-specific assessment measures. Linear regression was used to determine the relationship between perceived improvement, measured improvement, and VR volume.

RESULTS

The VR+SC group was able to traverse a greater distance in the assessment following the VR intervention. There was no significant difference in GROC between groups. For the VR+SC group, change in distance completed was not correlated with GROC, but GROC was correlated with VR volume.

CONCLUSION

VR improved the distance that participants were able to traverse in the assessment. However, the VR+SC group demonstrated a disconnect between their perceived functional improvement as measured by the GROC and functional improvement as measured by the change in the distance completed. Rather, the perceived improvement appears to be more correlated with the volume of VR received. The way in which the treatment progression is structured and communicated may influence how patients perceive their change in physical function.

Should I Stay or Should I Go? Identifying Intrinsic and Extrinsic Factors in the Decision to Return to Duty Following Lower Extremity Injury

INTRODUCTION

Rehabilitation research of wounded service members (SMs) commonly focuses on physical ability to return to duty (RTD) as a measure of successful recovery. However, numerous factors or barriers may influence a SM's ability and/or desire to RTD after lower extremity musculoskeletal trauma. SMs themselves as well as the clinical care team that works with them daily, often for years at a time, both offer unique perspectives on the influential factors that weigh into decisions to RTD. The purpose of this study was to identify the intrinsic and extrinsic factors patients and clinicians recognized as influencing the decision to RTD after severe lower extremity trauma.

MATERIALS AND METHODS

Thirty-two SMs with severe lower extremity trauma (amputation and lower limb salvage) and 30 providers with at least 2 years' experience caring for SMs with similar injuries participated separately in either a SM or provider/clinician focus group. Open-ended questions on factors influencing RTD and other rehabilitation success were discussed. Data analysis consisted of qualitative transcription and participatory active sorting, followed by thematic coding and grouping of qualitative data.

RESULTS

Individual (health condition, personal traits, and career consideration), interpersonal (clinician's impact, family influence, and peer influence), health care system (systems of care, transdisciplinary rehabilitation, and innovation availability), and institutional (policy, benefits, and unit/commander) themes emerged amongst SM patients and clinicians. Expected frequently occurring themes common to both groups were the influence of the team and family unit, as well as career trajectory options after a severe injury. An unexpected theme was acknowledgment of and dissatisfaction with the recent dismantling of institutional systems that support wounded SMs. Patients placed less emphasis on severity of injury and greater emphasis on system and policy barriers than did clinicians.

CONCLUSIONS

Characterization and classification of these clinician and SM-identified factors that influence the decision to RTD after severe lower extremity trauma is expected to improve the efficacy of future rehabilitation efforts and clinical practice guidelines by providing the clinical team the knowledge necessary to recognize modifiable barriers to patient success. A better understanding of factors influencing RTD decision-making may support policies for mitigating RTD barriers, better monitoring of the changing landscape of RTD after lower extremity trauma, improving systems of health care, and/or reducing turnover and facilitating force readiness.

The effect of custom carbon ankle-foot orthosis alignment on roll-over shape and center of pressure velocity

BACKGROUND

Maintaining an optimal rolling of the foot over the ground is thought to increase the stability and efficiency of pathologic gait. Ankle-foot orthoses are often prescribed to improve gait mechanics in individuals with lower extremity injuries; however, their design may compromise how the foot rolls over the ground.

OBJECTIVES

The aim of this study was to investigate the effects of the sagittal plane ankle-foot orthosis alignment on roll-over shape and center of pressure velocity in individuals with lower limb reconstructions.

STUDY DESIGN

Randomized cross-over study with a control group comparison.

METHODS

In total, 12 individuals with lower limb reconstruction who used a custom carbon ankle-foot orthosis and 12 uninjured controls underwent gait analysis. Ankle-foot orthosis users were tested in their clinically-provided ankle-foot orthosis alignment, with an alignment that was 3° more plantarflexed, and with an alignment that was 3° more dorsiflexed. Components of roll-over shape and center of pressure velocity were calculated from heel strike on the ankle-foot orthosis limb to contralateral heel strike.

RESULTS

Roll-over shape radius was not affected by 3° changes to alignment and was not significantly different from controls. Aligning the ankle-foot orthosis in more dorsiflexion than clinically provided resulted in a smaller peak center of pressure velocity that occurred later in stance.

CONCLUSION

Individuals using custom carbon ankle-foot orthoses can accommodate 3° alterations in the dorsiflexion or plantarflexion alignment.

Identifying Instruments to Assess Care Quality for Individuals With Custom Ankle Foot Orthoses: A Scoping Review

OBJECTIVES

We conducted 2 complementary scoping reviews to identify instruments that assess the experience and outcomes of custom ankle-foot orthosis (AFO) care in individuals with neurologic and traumatic conditions and to determine to what extent they might be psychometrically sound for AFO users. A stakeholder advisory committee considered to what extent the identified and psychometrically sound instruments might be feasible for use in developing quality measures for custom AFO users.

DATA SOURCES

Both scoping reviews were conducted using PubMed, the Cumulative Index to Nursing and Allied Health Literature, Embase, and Cochrane Systematic Reviews. The following were used for the first scoping review only: Cochrane Central Register of Controlled Trials and the Physiotherapy Evidence Database.

STUDY SELECTION

The initial scoping review yielded 79 articles with 82 instruments, 16 of which were used in 4 or more studies. The second scoping review yielded 57 articles reporting psychometric properties.

DATA EXTRACTION

Psychometric properties for populations who use AFOs were summarized for 15 of the 16 instruments. The advisory committee eliminated 2 insrtruments, noted overlap between 4 instruments in terms of the constructs measured, and suggested 6 potential contemporary substitutes.

DATA SYNTHESIS

Most instruments assessed activity (specifically mobility) and pertained to the National Quality Forum domain of "Health-Related Quality of Life." The 10-meter walk test, 6-minute walk test, Berg Balance Scale, Timed Up and Go, and Rivermead Mobility Index were reported to have adequate reliability and validity, and were considered feasible for administration in a clinical setting.

CONCLUSIONS

Complementary scoping reviews demonstrated that some instruments with reasonable psychometric properties are available that are feasible to use in developing quality measures for custom AFO care. However, experience of care instruments suitable for this population were not identified but are needed for a comprehensive evaluation of care quality for AFO users.

Health Outcomes Used to Determine Facets of Health-related Quality of Life for Post-9/11 Veterans Using Assistive Technology for A Combat-related Mobility Impairment: A Literature Review

INTRODUCTION

Novel rehabilitation methods, including distribution and adoption of assistive technology for lower extremity impairments, are becoming crucial to ensure positive quality of life in all individuals. The quality of life of post-9/11 combat veterans is not well understood, in comparison to research on other populations. The following essay describes a review on health outcomes used to determine health-related quality of life (HR-QoL) among combat-injured service members who require mobility-related assistive technology.

MATERIALS AND METHODS

Reviews pooled data from research on PubMed, EMBASE, CINAHL, and PsycINFO published after September 11, 2001, and included service members who sustained a mobility impairment because of involvement in a post-9/11 combat operation. Basic descriptors were extracted in addition to health outcomes used, which were then categorized and summarized by six domains for HR-QoL as defined by the World Health Organization.

RESULTS

This review found health outcomes that fit in the pain and discomfort, negative emotions, mobility, social relations, access to and quality of healthcare services, and religious/spiritual/personal beliefs subdomains. The categorized results detailed their application to track and model HR-QoL health states in those with mobility impairments using mobility-based assistive technology.

CONCLUSIONS

The research on combat-induced mobility impairments indicates assistive technology improves otherwise poor health states. The results model these domains and subdomains to determine overall HR-QoL and the quality of a healthcare intervention, though additional research is needed as only one study was identified to be experimental in design.

Custom Dynamic Orthoses and Physical Therapist Intervention for Bilateral Midfoot Amputation: A Case Report

OBJECTIVE

Partial foot amputation is often associated with decreased mobility and function. Recent advances in custom carbon-fiber dynamic ankle-foot orthoses (CDOs) have improved gait, pain, and function following musculoskeletal trauma and can benefit individuals with partial foot amputation. However, limited information is available related to CDO use outside the military. The purpose of this case report is to describe the course of care and outcomes of a civilian provided with CDOs after bilateral transmetatarsal amputation.

CASE DESCRIPTION

A 72-year-old man had a blood-borne bacterial infection (septicemia) of unknown origin at 68 years of age, developed limb-threatening necrosis of the hands and feet, and received bilateral transmetatarsal amputations with skin grafting. The patient initially used foam toe fillers and cushioned shoes but was functionally limited and experienced recurrent ulceration. He was fitted with bilateral CDOs 39 months after amputation and completed device-specific training with a physical therapist.

RESULTS

After 1 week with the CDOs, ankle range of motion during gait was reduced, but greater than 40% increases were observed in bilateral ankle plantarflexor moments and ankle plantarflexion push-off power compared with the toe fillers. With additional therapist-directed training focused on gait and activity performance, ankle plantarflexor moments and plantarflexion push-off power further increased when compared with results after 1 week of CDO use. The patient reported marked improvement in quality of life with the CDOs due to improved walking ability on level and uneven terrain, marked improvement in confidence, and reduced pain.

CONCLUSION

This case reflects the lessons learned and outcomes of a civilian using bilateral CDOs after bilateral transmetatarsal amputation and with poor skin quality. The results from this case study suggest that carbon-fiber CDOs and focused training by a physical therapist can result in improved gait biomechanics, mobility, and quality of life.

Custom foot orthoses improve performance, but do not modify the biomechanical manifestation of fatigue, during repeated treadmill sprints

PURPOSE

We determined the effect of custom foot orthotics manufactured from ethyl-vinyl acetate (EVA) and expanded thermoplastic polyurethane (TPU) materials, both compared to a control condition (CON; shoes only) during repeated sprints on running mechanical alterations.

METHODS

Eighteen males performed eight, 5-s sprints with 25-s recovery on an instrumented sprint treadmill in three footwear conditions (EVA, TPU and CON). Mechanical data consisted of continuous (step-by-step) measurement of running kinetics and kinematics, which were averaged for each sprint for further analysis.

RESULTS

Distance ran in 5 s decreased from first to last sprint (P < 0.001), yet with higher sprints 1-8 values for both EVA (P = 0.004) and TPU (P = 0.018) versus CON. Regardless of footwear condition, mean horizontal forces, step frequency, vertical and leg stiffness decreased from sprint 1 to sprint 8 (all P < 0.001). Duration of the propulsive phase was globally shorter for both EVA (P = 0.002) and TPU (P = 0.021) versus CON, while braking phase duration was similar (P = 0.919). In the horizontal direction, peak propulsive (P < 0.001), but not braking (P = 0.172), forces also decreased from sprint 1 to sprint 8, independently of conditions.

CONCLUSION

Compared to shoe only, wearing EVA or TPU custom foot orthotics improved repeated treadmill sprint ability, yet provided similar fatigue-induced changes in mechanical outcomes.

Clinical Outcomes with the Intrepid Dynamic Exoskeletal Orthosis: A Retrospective Analysis

INTRODUCTION

Severe lower limb injuries have a negative impact on many aspects of an individual's life. One rehabilitative option for patients who have undergone limb salvage is the Intrepid Dynamic Exoskeletal Orthosis (IDEO). The IDEO is a custom-made dynamic response device which is used to restore function for patients with a wide variety of injuries. Clinical outcomes were routinely collected on patients fit with IDEOs at the Center for the Intrepid, Brooke Army Medical Center. The purpose of this retrospective study was to analyze the clinical outcomes collection process and the patient outcomes collected as part of routine clinical care.

METHODS

The Brooke Army Medical Center IRB approved this study and granted waivers of informed consent and HIPAA authorization. Electronic medical records were reviewed over an 18-month period from July 2014 to January 2016. Records were examined to obtain the date of IDEO delivery, date of outcomes form completion, responses on the forms, and to verify diagnosis or injury. Data gathered included wear time, IDEO comfort, pain with and without the IDEO, Lower Extremity Functional Scale scores with and without the IDEO, and global rating of change questions for everyday activities and high impact activities. Wilcoxon signed-ranked tests were used to compare pain and function with vs. without the IDEO.

RESULTS

During the 18-month period, new IDEOs were delivered to 156 unique patients. Outcomes forms were collected as part of routine clinical care from 90 of these 156 patients (58%). An additional nine forms were collected from patients who received their IDEOs prior to July 2014. In all, 99 outcomes forms were collected. Mean follow-up time from IDEO delivery to outcomes form completion was 35 ± 31 days for the original 90 patients. The most common patient diagnoses were fracture, nerve injury, arthritis, and fusion. Responses on the forms indicated that patients were generally comfortable wearing their IDEOs (8.3 ± 1.3 on a 0-10 scale) and wore them most of the day (10.7 ± 3.4 hours per day). Improvement in pain (from 5.2 ± 2.9 to 1.7 ± 1.6 points on a 0-10 scale) and Lower Extremity Functional Scale scores (from 29.7 ± 16.6 to 59.5 ± 13.6 points) with the IDEO were both more than the minimal clinically important difference and were statistically significant (p < 0.001).

CONCLUSION

This descriptive retrospective study demonstrated that it was feasible to collect clinical outcomes data which were relevant for characterizing the effects of IDEO use and enabled quantification of improvements in self-reported function and walking pain with the IDEO. Due to the retrospective nature of this study, limitations include missing data and the lack of any performance measures to complement the self-reported data. Clinical outcomes collection continues as a routine part of clinical care and there remains an ongoing aim to collect information on all patients to obtain an accurate assessment of devices and services and ultimately better serve our patients.

Advanced Functional Bracing in Lower Extremity Trauma: Bracing to Improve Function

There are many bracing options for patients with functional limitations of the lower extremity following trauma. The first question that the provider must ask when evaluating a patient with a foot and ankle functional limitation because of weakness or pain is, "what are the patient's expectations?" One option for the patient who desires to return to a higher level of function is a novel, custom dynamic orthosis (CDO) that, when coupled with an advanced rehabilitation program, has improved outcomes in patients following lower extremity trauma who have plateaued after traditional rehabilitation pathways. Although this CDO and rehabilitation program has demonstrated success following lower extremity trauma in heterogenous patient populations, research is ongoing to identify both ideal referral diagnoses or injury characteristics, and to further optimize outcomes with the use of the CDO.

Closed Distal Dislocation of the Intermediate Cuneiform in a Complex Lisfranc Fracture-Dislocation: A Case Report

CASE

A 21-year-old, active duty male sustained an irreducible, complex Lisfranc fracture-dislocation with distal extrusion of his intermediate cuneiform. He was treated in a staged manner with external fixator placement, followed by an extended midfoot fusion with autograft bone. At 19 months, he could perform all activities of daily living independently with minimal pain using an Intrepid Dynamic Exoskeletal Orthosis.

CONCLUSIONS

Complex Lisfranc injuries are severe and often result in chronic pain and disability after operative management. To our knowledge, this is the only case report describing a Lisfranc fracture-dislocation with a distally extruded intermediate cuneiform treated with a fusion.

High-Level Performance After the Return to Run Clinical Pathway in Patients Using the Intrepid Dynamic Exoskeletal Orthosis

BACKGROUND

Severe ankle and foot injuries in the US military can result in high-level functional limitation, lost duty days, and medical discharge.

OBJECTIVE

To assess the effectiveness of the Return to Run Clinical Pathway (RTR) in returning patients with lower extremity fractures who utilized the Intrepid Dynamic Exoskeletal Orthosis (IDEO) to high-level mobility.

METHODS

Thirty servicemembers with lower extremity fractures who utilized the IDEO unilaterally and completed the RTR at Naval Medical Center San Diego were included in this retrospective operational review. The Comprehensive High-level Activity Mobility Predictor (CHAMP) and all subtests were completed prior to and after completion of the RTR as part of routine clinical care. An analysis of covariance (ANCOVA) was used to compare CHAMP scores before and after the RTR.

RESULTS

Significant improvements were found in the T test (mean change, faster by 5.3 seconds; 95% confidence interval: 3.6, 7.1 seconds; P = .03) and total CHAMP score (mean change, 4.2 points; 95% confidence interval: 3.0, 5.3 points; P<.05). No significant changes were noted in the single-legged stance subtest, the Edgren sidestep test, or the Illinois agility test.

CONCLUSION

The RTR led to improvements in high-level, multidirectional mobility in IDEO users with a history of fractures. Applicability of the intervention used in this study requires further validation before widespread use.

LEVEL OF EVIDENCE

Therapy, level 4. J Orthop Sports Phys Ther 2019;49(7):529-535. Epub 13 Feb 2019. doi:10.2519/jospt.2019.8763.

A study on the efficacy of AFO stiffness prescriptions

PURPOSE

Ankle foot orthosis (AFO) stiffness is a key characteristic that determines how much support or restraint an AFO can provide. Thus, the goal of the current study is twofold: (1) to quantify AFO prescriptions for a group of patients; (2) to evaluate what impact these AFO have on the push-off phase.

METHOD

Six patients were included in the study. Three patients were prescribed an AFO for ankle support and three patients were prescribed an AFO for ankle and knee support. Two types of AFO - a traditional polypropylene AFO (AFOPP) and a novel carbon-selective laser sintered polyamide AFO (AFOPA), were produced for each patient. AFO ankle stiffness was measured in a dedicated test rig. Gait analysis was performed under shod and orthotic conditions.

RESULTS

Patient mass normalized AFOPP stiffness for ankle support ranged from 0.042 to 0.069 N·m·deg^-1·kg^-1, while for ankle and knee support it ranged from 0.081 to 0.127 N·m·deg^-1·kg^-1. On the group level, the ankle range of motion and mean ankle velocity in the push-off phase significantly decreased in both orthotic conditions, while peak ankle push-off power decreased non-significantly. Accordingly, on the group level, no significant improvements in walking speed were observed. However, after patient differentiation into good and bad responders it was found that in good responders peak ankle push-off power tended to be preserved and walking speed tended to increase.

CONCLUSIONS

Quantification of AFO stiffness may help to understand why certain orthotic interventions are successful (unsuccessful) and ultimately lead to better AFO prescriptions. Implications for rehabilitation AFO ankle stiffness is key characteristic that determines how much support or restraint an AFO can provide. In a typical clinical setting, AFO ankle stiffness is not quantified. AFO has to meet individual patient's biomechanical needs. More objective AFO prescription and more controlled AFO production methods are needed to increase AFO success rate.

Ankle-foot orthosis alignment affects running mechanics in individuals with lower limb injuries

BACKGROUND

Individuals with severe lower extremity injuries often require ankle-foot orthoses to return to normal activities. Ankle-foot orthoses alignment is a key consideration during the clinical fitting process and may be particularly important during dynamic activities such as running.

OBJECTIVE

To investigate how 3° changes in sagittal plane ankle-foot orthoses alignment affect running mechanics.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve participants with unilateral lower limb injury ran overground and lower extremity running mechanics were assessed. Participants wore their passive-dynamic ankle-foot orthoses in three alignments: clinically fit neutral, 3° plantarflexed from clinically fit neutral, and 3° dorsiflexed from clinically fit neutral.

RESULTS

The 3° changes in sagittal alignment significantly influenced ankle mechanics during running. The plantarflexed alignment significantly decreased the peak ankle plantarflexor moment, peak knee extensor moment, and peak ankle and knee power absorption and generation compared to more dorsiflexed alignments. Alignment also altered footstrike angle, with dorsiflexed alignments associated with a more dorsiflexed footstrike pattern and plantarflexed alignments toward a more plantarflexed footstrike pattern. However, alignment did not influence loading rate.

CONCLUSION

Small changes in ankle-foot orthoses alignment significantly altered running mechanics, including footstrike angle, and knee extensor moments. Understanding how ankle-foot orthoses design parameters affect running mechanics may aid the development of evidence-based prescription guidelines and improve function for ankle-foot orthoses users who perform high-impact activities.

CLINICAL RELEVANCE

Understanding how ankle-foot orthoses alignment impacts biomechanics should be a consideration when fitting passive-dynamic devices for higher impact activities, such as running. Individual running styles, including footstrike patterns, may be affected by small changes in alignment.

Do Spatiotemporal Gait Parameters Improve After Pilon Fracture in Patients Who Use the Intrepid Dynamic Exoskeletal Orthosis?

BACKGROUND

Pilon fractures are high-energy fractures about the ankle observed commonly in both civilian and military trauma populations. Despite surgical management, outcomes are predictably poorly characterized by functional deficits secondary to pain and stiffness. The Intrepid Dynamic Exoskeletal Orthosis (IDEO) and Return-to-Run clinical pathway were initially designed to treat military service members after complex battlefield lower extremity injuries. The IDEO has been used to treat nonbattlefield injuries, but, to our knowledge, it has not been studied specifically among patients with pilon fractures. By studying the use of the IDEO in this patient population, we hope to learn how it might improve ambulation in the community, relieve pain, and return patients to work to better identify patients who might benefit from its use.

QUESTIONS/PURPOSES

The purpose of this study was to determine whether the IDEO would improve gait parameters including velocity, cadence, stride length, and single-leg stance duration in patients with pilon fractures. Our secondary endpoints of interest were reductions in pain and return to duty.

METHODS

A prospectively collected database of all active-duty IDEO users at a single institution was queried for all patients using the IDEO after a pilon fracture. Patients were included if they were using the IDEO after sustaining a surgically treated pilon fracture and had exhausted all nonoperative therapies. Exclusions were patients with an incomplete gait analysis at the two study time points. Seven patients meeting these criteria were identified. Three-dimensional gait analysis was performed two times: first wearing shoes at a self-selected speed and second after a custom-made IDEO was fabricated for the patient and completion of the Return-to-Run pathway. Patients reported their average pain while ambulating using a numeric rating scale. Gait variables of interest were velocity, cadence, stride length, and single stance time. Return to military service was assessed through the military medical record. To return to duty, a service-specific physical readiness test must be completed.

RESULTS

Median gait velocity improved from 1.1 (interquartile range [IQR], 0.9-1.2) to 1.3 m/s (IQR, 1.2-1.5; p = 0.01). All other variables did not change: cadence 98.4 (IQR, 93.0-107.2) to 104.5 steps/min (IQR, 103.0-109.0; p = 0.13), affected stride length 1.3 (IQR, 1.0-1.4 m) to 1.4 m (IQR, 1.3-1.6 m; p = 0.07), and affected single stance 0.42 (IQR, 0.41-0.47) to 0.43 (IQR, 0.42-0.44; p = 0.80). Pain did not change between time points: 3 (IQR, 2-3) to 2.5 (IQR, 1-3.5; p = 0.90). Three of seven patients returned to duty.

CONCLUSIONS

At self-selected walking speeds, we observed no improvements in gait parameters or pain after application of the IDEO that would likely be considered clinically important, and so the device is unlikely to be worth the cost in this setting. It is possible that for higher demand users such as elite athletes, the IDEO could have a role after severe lower extremity trauma; however, this must be considered speculative until or unless proven in future studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Ankle Arthrodesis for Talar Avascular Necrosis and Arthrodesis Nonunion

This article reviews the surgical treatment of talar avascular necrosis. Specifically, arthrodesis for this complex entity and potential treatment of nonunions are discussed. The hallmarks of treatment are evolving and can range from nonoperative measures to amputations. Nonoperative treatment and the results of current arthrodesis techniques for late-stage avascular necrosis are reviewed. Surgical correction requires an understanding of the condition's natural history, utilization of structural and nonstructural bone grafting techniques, and stable fixation. Although the methods described follow standard orthopedic principles, high-quality evidence and outcome studies are limited for treatment of this challenging and often disabling condition.

Experimental comparisons of passive and powered ankle-foot orthoses in individuals with limb reconstruction

BACKGROUND

Ankle-foot orthoses (AFO) are commonly prescribed to provide functional assistance for patients with lower limb injuries or weakness. Their passive mechanical elements can provide some energy return to improve walking ability, but cannot restore plantar flexor push-off. Powered AFOs provide an assistive torque about the ankle to address the limitations of passive devices, but current designs have yet to be implemented on a large scale clinically.

PURPOSE

To compare passive AFOs to a new untethered, powered AFO design in a clinical population with lower limb reconstruction.

METHODS

A crossover study design, conducted on three individuals with lower limb reconstruction, compared gait mechanics at a standardized speed (based on leg length) in 4 AFO conditions: 1. None (shoes only), 2. Blue Rocker (BR, Allard, USA), 3. Intrepid Dynamic Exoskeletal Orthosis (IDEO), and 4. PowerFoot Orthosis (PFO BionX Medical Technologies, Inc.). The PFO was a custom, battery-powered device whose damping and power were capable to being tuned to meet patient needs. Subjects performed biomechanical gait analysis and metabolic testing at slow, moderate and fast speeds. Dependent variables included total limb power (calculated using a unified deformable segment model), mechanical work, mechanical efficiency, ankle motion, net metabolic cost across three speeds, and performance measures were calculated. Effect sizes (d) were calculated and d > 0.80 denoted a large effect.

RESULTS

Net positive work (d > 1.17) and efficiency (d > 1.43) were greatest in the PFO. There were large effects for between limb differences in positive work for all conditions except the PFO (d = 0.75). The PFO normalized efficiency between the affected and unaffected limbs (d = 0.50), whereas efficiency was less on the affected limb for all other conditions (d > 1.69). Metabolic rate was not consistently lowest in any one AFO condition across speeds. Despite some positive results of the PFO, patient preferred their daily use AFO (2 IDEO, 1 BR). All participants indicated that mass and size were concerns with using the PFO.

CONCLUSIONS

A novel PFO resulted in more biomimetic mechanical work and efficiency than commercially-available and custom passive AFO models. Although the powered AFO provided some biomechanical benefits, further improvements are warranted to improve patient satisfaction.

Multisite Evaluation of a Custom Energy-Storing Carbon Fiber Orthosis for Patients with Residual Disability After Lower-Limb Trauma

BACKGROUND

The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a custom energy-storing carbon fiber ankle-foot orthosis developed for lower-extremity trauma patients. Studies conducted at the military treatment facility where the IDEO was developed demonstrated benefits of the IDEO when used with the Return to Run Physical Therapy (RTR PT) program. The current study was designed to determine if results could be replicated at other military treatment facilities and to examine whether early performance gains in patient-reported functional outcomes remained at 12 months.

METHODS

Study participants included service members who had functional deficits that interfered with daily activities at least 1 year after a traumatic unilateral lower-extremity injury at or below the knee. Participants were evaluated before receiving the IDEO, immediately following completion of RTR PT, and at 6 and 12 months. Agility, strength/power, and speed were assessed using well-established performance tests. Self-reported function was measured using the Short Musculoskeletal Function Assessment (SMFA). The Orthotics and Prosthetics Users' Survey was administered to assess satisfaction with the IDEO. Of 87 participants with complete baseline data, 6 did not complete any physical therapy and were excluded from the analysis. Follow-up rates immediately following completion of the RTR PT and at 6 and 12 months were 88%, 75%, and 79%, respectively.

RESULTS

Compared with baseline, improvement at completion of RTR PT was observed in all but 1 performance test. SMFA scores for all domains except hand and arm function were lower (improved function) at 6 and 12 months. Satisfaction with the IDEO was high following completion of RTR PT, with some attenuation at the time of follow-up.

CONCLUSIONS

This study adds to the evidence supporting the efficacy of the IDEO coupled with RTR PT. However, despite improvement in both performance and self-reported functioning, deficits persist compared with population norms.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effects of altering heel wedge properties on gait with the Intrepid Dynamic Exoskeletal Orthosis

BACKGROUND

The Intrepid Dynamic Exoskeletal Orthosis is a custom-made dynamic response carbon fiber device. A heel wedge, which sits in the shoe, is an integral part of the orthosis-heel wedge-shoe system. Because the device restricts ankle movement, the system must compensate to simulate plantarflexion and allow smooth forward progression during gait.

OBJECTIVES

To determine the influence of wedge height and durometer on the walking gait of individuals using the Intrepid Dynamic Exoskeletal Orthosis.

STUDY DESIGN

Repeated measures.

METHODS

Twelve individuals walked over level ground with their Intrepid Dynamic Exoskeletal Orthosis and six different heel wedges of soft or firm durometer and 1, 2, or 3 cm height. Center of pressure velocity, joint moments, and roll-over shape were calculated for each wedge.

RESULTS

Height and durometer significantly affected time to peak center of pressure velocity, time to peak internal dorsiflexion and knee extension moments, time to ankle moment zero crossing, and roll-over shape center of curvature anterior-posterior position. Wedge height had a significant influence on peak center of pressure velocity, peak dorsiflexion moment, time to peak knee extension moment, and roll-over shape radius and vertical center of curvature.

CONCLUSION

Changes in wedge height and durometer systematically affected foot loading. Participants preferred wedges which produced ankle moment zero crossing timing, peak internal knee extension moment timing, and roll-over shape center of curvature anterior-posterior position close to that of able-bodied individuals. Clinical relevance Adjusting the heel wedge is a simple, straightforward way to adjust the orthosis-heel wedge-shoe system. Changing wedge height and durometer significantly alters loading of the foot and has great potential to improve an individual's gait.

Assessment of Mechanical Characteristics of Ankle-Foot Orthoses

Recent designs of ankle-foot orthoses (AFOs) have been influenced by the increasing demand for higher function from active individuals. The biomechanical function of the individual and device is dependent upon the underlying mechanical characteristics of the AFO. Prior mechanical testing of AFOs has primarily focused on rotational stiffness to provide insight into expected functional outcomes; mechanical characteristics pertaining to energy storage and release have not yet been investigated. A pseudostatic bench testing method is introduced to characterize compressive stiffness, device deflection, and motion of solid-ankle, anterior floor reaction, posterior leaf spring, and the intrepid dynamic exoskeletal orthosis (IDEO) AFOs. Each of these four AFOs, donned over a surrogate limb, were compressively loaded at different joint angles to simulate the foot-shank orientation during various subphases of stance. In addition to force–displacement measurements, deflection of each AFO strut and rotation of proximal and supramalleolar segments were analyzed. Although similar compressive stiffness values were observed for AFOs designed to reduce ankle motion, the corresponding strut deflection profile differed based on the respective fabrication material. For example, strut deflection of carbon-fiber AFOs resembled column buckling. Expanded clinical test protocols to include quantification of AFO deflection and rotation during subject use may provide additional insight into design and material effects on performance and functional outcomes, such as energy storage and release.

Physical Performance Limitations After Severe Lower Extremity Trauma in Military Service Members

OBJECTIVES

To characterize the type and magnitude of lower extremity physical performance deficits in military service members who have undergone rehabilitation after limb salvage or transtibial amputation.

DESIGN

Cross-sectional prospective.

SETTING

Level I trauma military medical and rehabilitation center.

PATIENTS/PARTICIPANTS

Service members with lower extremity trauma resulting in limb salvage (n = 20) or unilateral transtibial amputation (n = 14) compared with uninjured actively training service members (n = 123).

INTERVENTION

Control participants and individuals with amputation were tested during a single session. Participants with limb salvage were tested with and without the use of a custom carbon fiber orthosis.

MAIN OUTCOME MEASUREMENTS

Physical performance as measured using four-square step, sit-to-stand 5 times, and timed stair ascent tests. Secondary outcomes included the associations between these lower extremity activity measures to determine the interrelationship of activity limitations.

RESULTS

The ability of service members to rapidly ascend stairs, a demanding lower limb mobility task, is limited after amputation and limb salvage. However, performance on an agility test similar to the four-square step test approximated normative levels. Differences between individuals with amputation or limb salvage were less than 1 second for all tests and were not statistically significant. Correlations were observed among the physical performance measures in the tested patient populations, particularly between the sit-to-stand and timed stair ascent tests.

CONCLUSIONS

Severe limb trauma significantly affects performance, particularly during tasks requiring lower extremity strength and power. Individuals with amputation or limb salvage who were provided a custom carbon fiber orthosis and intensive rehabilitation had similar performance.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Combat-related foot injuries: impact on gait and functional outcome

Introduction

Prior to deployment of the Netherlands Army Task Force Urozgan in Afghanistan, the Dutch Military and civilian healthcare systems had limited experience in treating blast injuries and their long-term consequences. This meant that guidelines for treatment and rehabilitation were lacking. The aim of this cohort study was to quantify kinematic and kinetic abnormalities in service members with foot injuries in relation to functional outcome using gait analysis.

Method

In nine service members with combat-related talus, calcaneus and/or navicular bone (TCN) fractures and nine controls, gait parameters were measured using Gait Real-Time Analysis Interactive Lab system. High-level mobility was evaluated by the Comprehensive High-Level Activity Mobility Predictor (CHAMP), and functional ability was assessed by Lower Extremity Functional Scale (LEFS) questionnaire.

Results

Significant differences were found for LEFS and CHAMP scores (P<0.01), comfortable walking speed and ankle joint range of motion (ROM) (P<0.05), all lower in the group with TCN fractures. For this group, a trend (0.1>P>0.05) for higher step width and lower stride duration and peak power was found. A strong correlation (0.6>r>0.79) is shown between LEFS and comfortable walking speed and CHAMP and ankle joint ROM. The correlations between LEFS and stride duration, step width, ankle joint ROM and peak power, and between CHAMP and comfortable walking speed and stride duration, were moderate (0.4>r>0.59).

Conclusions

This study demonstrated that service members with TCN fractures, compared with healthy controls, have altered gait characteristics, specifically lower walking speed and ankle joint ROM, both related to lower physical functioning. Patients with bilateral depressed Böhler’s angle had the worse functional performance, and further research is recommended to evaluate the relationship between Böhler’s angle and physical performance.

Clinical Trial

The Dutch Ministry of Defence (MOD) and the Institutional Review Board and Medical Ethics Review Committee Brabant, The Netherlands, approved this study (P1550).