Ankle and foot kinematics associated with stage II PTTD during stance

Lower limbs biomechanical deficits associated with stage 1 and 2 posterior tibialis tendon dysfunction during walking

BACKGROUND

Posterior tibialis tendon dysfunction (PTTD) is a chronic degenerative musculoskeletal disorder causing a progressive ankle complex and arch collapse altering lower limb biomechanics. However, biomechanical changes associated with stage 1 and 2 PTTD need to be better characterized during walking to guide clinical recommendations and improve non-operative treatments.

RESEARCH QUESTION

What are the lower limb kinematic and kinetic differences between individuals with stage 1 (PTTD1), individuals with stage 2 PTTD (PTTD2) and healthy counterparts during gait?

METHODS

Sixteen PTTD1, 11 PTTD2 and 20 healthy controls were included in this multicentric case-control study to compare their lower limb gait biomechanics. Kinematic and kinetic data were recorded using a three-dimensional motion capture system and a force plate. One-dimensional statistical parametric mapping was used to compare lower limb joint motion and moments between groups during the stance phase.

RESULTS

PTTD1 had minimal biomechanical differences compared with the control group. In contrast, PTTD2 presented significant differences compared with controls and PTTD1. At the ankle, PTTD2 exhibited greater plantarflexion and eversion angles and midfoot dorsiflexion and inversion angles throughout stance compared with controls and PTTD1. PTTD2 presented lower midfoot abduction moments compared with controls. These changes led PTTD2 to exhibit knee and hip adaptative biomechanical mechanisms in the frontal and transverse planes in late stance. PTTD2 had greater knee internal rotation angles and smaller knee external rotation moments compared to controls. PTTD2 had smaller hip internal rotation angles compared with PTTD1 and smaller hip adduction moments compared with controls.

SIGNIFICANCE

PTTD1 showed minimal biomechanical differences compared to controls and important differences compared to PTTD2. The lower limb biomechanical deficits accentuate as the pathology advances from stage 1 to stage 2. PTTD is a progressive condition needing early clinical management at stage 1 to avoid successive biomechanical changes associated with stage 2.

Comparison of Foot Kinematics Between Normal Arch and Flexible Flatfoot Using the Oxford Foot Model: A Matched Case-Control Study

Background

Symptomatic flexible flatfoot causes alterations in gait, but exactly how this condition affects the intersegmental motion of the foot during the gait cycle remains unclear. Previous studies have examined the kinematics, yielding inconsistent findings. Therefore, the objective of this study was to investigate how flexible flatfoot deformity, defined as Johnson and Strom classification staging II, affects the intersegmental motion of the foot during fast walking based on a comparison with the matched control group.

Methods

Eleven participants with symptomatic flexible flatfoot and 11 healthy matched control participants were recruited using a foot screening protocol incorporated through a foot physical examinations and radiographic measurements. All demographic characteristics exhibited comparable profiles between the groups. During controlled walking, kinematic outcomes pertaining to the hallux, hindfoot, forefoot, and tibia were collected using the multisegmental Oxford Foot Model.

Results

All spatiotemporal parameters were comparable between the groups. In comparison to the control group, individuals with symptomatic flexible flatfoot demonstrated increased hallux valgus and plantarflexion, increased forefoot abduction, heightened hindfoot eversion, and internal rotation. Notably, no significant major differences were observed in the tibia motion segment. Further, significant correlations were identified between static foot measurements and the extent of the maximum deviation observed during dynamic kinematic assessments.

Conclusion

Compared with age- and gender-matched controls, participants with symptomatic flexible flatfoot exhibited significant gait pattern deviations. A significant correlation also exists between static foot deformity measurements and dynamic kinematic deviations. Collectively, these findings have implications for developing targeted therapeutic interventions to address flexible flatfoot.

Level of evidence

Level III, diagnostic study.

Increase in lateral contact force in the tibiotalar joint during walking in flatfoot patients with reduced stiffness of the spring ligament

Foot deformities in patients with flexible flatfeet, such as the flattened medial arch and hindfoot valgus, affect the force distribution around the tibiotalar joint during walking and increase the risk of secondary injuries. In this study, we developed a multi-segment foot model that could calculate the dynamics around the tibiotalar joint and investigated the difference in the kinetics between normal feet and feet with flatfoot. Ten participants with normal feet and ten with flexible flatfoot were enrolled in the study. The body kinematics, ground reaction force, and foot pressure of the participants were recorded during walking. A five-segment foot model was developed to calculate contact forces in the tibiotalar joint. A flatfoot model was developed by modifying the stiffness of the spring ligaments of a normal foot model. Ground reaction force was applied to the plantar surface of the foot models. The foot models were attached to a full-body musculoskeletal model to conduct inverse dynamic simulations of walking. Participants with flatfoot had significantly greater lateral contact force (1.19 BW vs. 0.80 BW) and more posteriorly located center of pressure (33.7 % vs. 46.6 %) in the tibiotalar joint than those with normal feet (p < 0.05). The average and peak posterior tibialis muscle forces were significantly larger in participants with flatfoot than in those with normal feet (3.06 BW vs. 2.22 BW; 4.52 BW vs. 3.33 BW). The altered mechanics may influence the risk of arthritis.

Influence of the center of pressure on baropodometric gait pattern variations in the adult population with flatfoot: A case-control study

Background: Adult flatfoot is considered an alteration in the foot bone structure characterized by a decrease or collapse of the medial arch during static or dynamic balance in the gait pattern. The aim of our research was to analyze the center of pressure differences between the population with adult flatfoot and the population with normal feet.

Methods: A case-control study involving 62 subjects was carried out on 31 adults with bilateral flatfoot and 31 healthy controls. The gait pattern analysis data were collected employing a complete portable baropodometric platform with piezoresistive sensors.

Results: Gait pattern analysis showed statistically significant differences in the cases group, revealing lower levels in the left foot loading response of the stance phase in foot contact time (p = 0.016) and contact foot percentage (p = 0.019).

Conclusion: The adult population with bilateral flatfoot evidenced higher contact time data in the total stance phase compared to the control group, which seems to be linked to the presence of foot deformity in the adult population.

Characteristics and Future Direction of Tibialis Posterior Tendinopathy Research: A Scoping Review

Background and Objectives: Tibialis posterior tendon pathologies have been traditionally categorized into different stages of posterior tibial tendon dysfunction (PTTD), or adult acquired flatfoot deformity (AAFD), and more recently to progressive collapsing foot deformity (PCFD). The purpose of this scoping review is to synthesize and characterize literature on early stages of PTTD (previously known as Stage I and II), which we will describe as tibialis posterior tendinopathy (TPT). We aim to identify what is known about TPT, identify gaps in knowledge on the topics of TPT, and propose future research direction. Materials and Methods: We included 44 studies and categorized them into epidemiology, diagnosis, evaluation, biomechanics outcome measure, imaging, and nonsurgical treatment. Results: A majority of studies (86.4%, 38 of 44 studies) recruited patients with mean or median ages greater than 40. For studies that reported body mass index (BMI) of the patients, 81.5% had mean or median BMI meeting criteria for being overweight. All but two papers described study populations as predominantly or entirely female gender. Biomechanical studies characterized findings associated with TPT to include increased forefoot abduction and rearfoot eversion during gait cycle, weak hip and ankle performance, and poor balance. Research on non-surgical treatment focused on orthotics with evidence mostly limited to observational studies. The optimal exercise regimen for the management of TPT remains unclear due to the limited number of high-quality studies. Conclusions: More epidemiological studies from diverse patient populations are necessary to better understand prevalence, incidence, and risk factors for TPT. The lack of high-quality studies investigating nonsurgical treatment options is concerning because, regardless of coexisting foot deformity, the initial treatment for TPT is typically conservative. Additional studies comparing various exercise programs may help identify optimal exercise therapy, and investigation into further nonsurgical treatments is needed to optimize the management for TPT.

Biomechanical Effects of Surgical Reconstruction for Flexible Progressive Collapsing Foot Deformity: A Systematic Review

BACKGROUND

Symptomatic progressive collapsing foot deformity (PCFD) is frequently treated with reconstructive surgery. Multiple studies have documented successful treatment based on improvements in symptoms and physical examination findings. However, it is not well-established whether there are corresponding improvements in gait function following surgical treatment for PCFD.

METHODS

A systematic review of biomechanical outcomes of treatments for flexible PCFD was conducted on PubMed. The 4 articles chosen involved patients with symptomatic flexible PCFD who underwent a reconstructive surgery. Surgical interventions included osteotomy, tendon transfer, and/or ligament repair or reconstruction. Primary outcomes involved objective quantifiable measurements of kinematic, kinetic, or temporospatial parameters.

RESULTS

The initial search yielded 605 articles, from which 26 were retained after screening the title and abstract. Twenty-two were eliminated yielding 4 articles. Temporospatial, kinematic, and kinetic parameters were all altered after the patients underwent surgical intervention. Specifically, stride length, cadence, and walking speed all improved postoperatively. Walking kinetics also improved with restoration of normal motion in the frontal and sagittal planes and improvements in the dorsiflexion angle. There were also improvements in sagittal power.

DISCUSSION

Surgical intervention to treat flexible PCFD improves objective biomechanical outcomes; however, more follow-up studies are needed to establish the reliability and durability of these improvements.

LEVEL OF EVIDENCE

Level III: Systematic review.

Posterior tibial tendon dysfunction alters the midfoot mechanics and energetics during gait

A comprehensive insight into the in vivo foot kinetics of patients with posterior tibial tendon dysfunction (PTTD) is lacking to support clinical decision making. Our goal was to study how PTTD alters the kinetic and kinematic characteristics of the foot and ankle with a special focus on the midfoot joints. Multisegment foot joint kinetics and kinematics were compared based on the Rizzoli Foot Model and inversed dynamics between a control group (n = 25), patients with PTTD Stage II (n = 21) and PTTD Stage III (n = 4) over the entire stance phase. Compared to controls, a mean decrease in power generation of 1.3 W/kg was found in the Ankle joint in PTTD II patients (p < 0.001) and PTTD III patients of 1.5 W/kg (p < 0.001). In the Chopart joint, there was a mean increase in power absorption of 0.4 W/kg in the PTTD III patients (p = 0.014) and a mean decrease in power generation of 0.6 W/kg (p < 0.001) in the PTTD II patients. The distribution of total negative work showed a shift from the Ankle and first metatarsal phalangeal joint towards the Chopart joint in both PTTD compared with the control subjects. A significant reduction in range of motion was observed among both PTTD groups. The outcome of this study will enable the possibility to customize the conservative and surgical treatment of each patient with PTTD, to improve or even restore the kinetic features. This will prevent the natural deterioration of function seen in this pathology.

Injuries to the Spring Ligament: Nonoperative Treatment

The fibrocartilage within the superomedial calcaneonavicular (spring) ligament is part of an interwoven complex of ligaments that span the ankle, subtalar, and talonavicular joints. Acute isolated rupture of the spring ligament has been reported in association with an eversion ankle sprain. Attenuation and failure of the spring ligament causes complex 3D changes called the progressive collapsing foot deformity (PCFD). This deformity is characterized by hindfoot eversion, forefoot supination, collapse of the medial longitudinal arch, and forefoot abduction. Nonoperative treatment of an isolated spring ligament rupture and PCFD using various designs of orthoses have shown promising results.

How does the postoperative medial arch height influence the patient reported outcomes of stage Ⅱ acquired adult flatfoot deformity?

BACKGROUND

This study aimed to assess how the postoperative medial arch height influenced postoperative patient-reported clinical outcomes after surgery for stage Ⅱ acquired adult flatfoot deformity.

METHODS

A total of 30 feet of 30 patients (7 males, 23 females) who underwent surgery for stage Ⅱ acquired adult flatfoot deformity and could be followed up for at least 2 years were included. The average age at surgery was 60.0 (standard deviation, 13.0) years, and the average follow-up period was 40 (standard deviation, 15.4) months. Among them, 16 patients underwent lateral column lengthening and 14 patients did not. Patient-reported clinical outcomes were evaluated using the Self-Administered Foot Evaluation Questionnaire. Radiographic alignment was evaluated by the talonavicular coverage angle, lateral talo-1st metatarsal angle, medial cuneiform height, medial cuneiform to 5th metatarsal height, and calcaneal pitch. The correlation between postoperative Self-Administered Foot Evaluation Questionnaire and radiographic alignment was assessed with Pearson's correlation analysis.

RESULTS

Self-Administered Foot Evaluation Questionnaire and radiographic alignment significantly improved postoperatively in all patients (P < 0.0001). In patients with severe deformity who needed lateral column lengthening, lateral talo-1st metatarsal angle was negatively and medial cuneiform to 5th metatarsal height was positively correlated with physical functioning Self-Administered Foot Evaluation Questionnaire subscales (r = -0.56 and 0.55), and medial cuneiform height was positively correlated with physical functioning, social functioning and general health Self-Administered Foot Evaluation Questionnaire subscales (r = 0.70, 0.55 and 0.73, respectively).

CONCLUSION

Postoperative medial arch height could influence physical functioning, social functioning, and general health in patients with severe stage II adult-acquired flatfoot deformity.

Ankle plantar flexor muscle performance and patient reported outcomes in people following total ankle arthroplasty

BACKGROUND

The purpose of this study was to prospectively evaluate ankle power generation during gait in people with total ankle arthroplasty, and examine the relationships between postoperative plantar flexor strength, ankle power, and patient outcomes.

METHODS

Nineteen people with end-stage ankle arthritis who received a total ankle arthroplasty and 19 healthy matched controls participated in this case-control study. Patient reported outcomes included a region specific measure of foot function and a generic measure of physical function. Gait speed was recorded with the 6-min walk test. Isokinetic plantar flexor strength was measured with an instrumented dynamometer. Motion capture and force plate data were used to calculate peak ankle power generation during walking. Paired or independent t-tests were used to compare ankle power across time and between groups, respectively. Bivariate correlations were performed to examine the interplay of postoperative strength, ankle power, gait speed, and patient reported outcomes.

FINDINGS

Ankle power was not different between the preoperative and 6-month postoperative time points (d = 0.20). Six-month postoperative ankle power was less than controls (d = 1.32). Strength, ankle power, and gait speed were directly correlated in the patient group 6-months postoperatively (r or ρ ≥ 0.47). Six-month postoperative strength and ankle power were directly correlated to select 2-year patient reported outcomes (both ρ = 0.54).

INTERPRETATION

Lower than normal 6-month postoperative ankle power, which was correlated to strength, gait speed, and longer-term patient reported outcomes, suggests efforts toward improving ankle plantar flexor muscle performance may improve patient outcomes.

Postural Control Differences between Patients with Posterior Tibial Tendon Dysfunction and Healthy People during Gait

BACKGROUND

Patients with posterior tibial tendon dysfunction (PTTD) may exhibit postural instability during walking likely due to a loss of medial longitudinal arch, abnormal foot alignment, and pain. While many studies have investigated gait alterations in PTTD, there is no understanding of dynamic postural control mechanisms in this population during gait, which will help guide rehabilitation and gait training programs for patients with PTTD. The purpose of the study was to assess dynamic postural control mechanisms in patients with stage II PTTD as compared to age and gender matched healthy controls.

METHODS

Eleven patients with stage II PTTD (4 males and 7 females; age 59 ± 1 years; height 1.66 ± 0.12 m; mass 84.2 ± 16.0 kg) and ten gender and age matched controls were recruited in this study. Participants were asked to walk along a 10 m walkway. Ten Vicon cameras and four AMTI force platforms were used to collect kinematic and center of pressure (COP) data while participants performed gait. To test differences between PTTD vs. control groups, independent t-tests (set at α < 0.05) were performed.

RESULTS

Patients with PTTD had significantly higher double stance ratio (+23%) and anterior-posterior (AP) time to contact (TTC) percentage (+16%) as compared to healthy control. However, PTTD had lower AP COP excursion (-19%), AP COP velocity (-30%), and medial-lateral (ML) COP velocity (-40%) as compared to healthy controls. Mean ML COP trace values for PTTD were significantly decreased (-23%) as compared to controls, indicating COP trace for PTTD tends to be closer to the medial boundary than controls during single-support phase of walking.

CONCLUSION

PTTD patients showed more conservative and cautious postural strategies which may help maintain balance and reduce the need for postural adjustment during PTTD gait. They also showed more medially shifted COP patterns than healthy controls during single-support phase of walking. Dynamic postural control outcomes could be used to develop effective gait training programs aimed at alleviating a medial shift of COP (everted foot) for individuals with PTTD in order to improve their functionality and gait efficiency.

Midfoot Function Before and After Total Ankle Arthroplasty

BACKGROUND

Information regarding the effect of total ankle arthroplasty (TAA) on midfoot function is extremely limited. The purpose of this study was to characterize midfoot region motion and power during walking in people before and after TAA.

METHODS

This was a prospective cohort study of 19 patients with end-stage ankle arthritis who received a TAA and 19 healthy control group participants. A motion capture and force plate system was used to record sagittal and transverse plane first metatarsal and lateral forefoot with respect to hindfoot motion, as well as sagittal plane midfoot region positive and negative peak power during walking. Parametric or nonparametric tests to examine differences and equivalence across time were conducted. Comparisons to examine differences between postoperative TAA group and control group foot function were also performed.

RESULTS

Involved-limb midfoot function was not different between the preoperative and 6-month postoperative time point in the TAA group (all P ≥ .17). Equivalence testing revealed similarity in all midfoot function variables across time (all P < .05). Decreased first metatarsal and lateral forefoot motion, as well as positive peak power generation, were noted in the TAA group postoperative involved limb in comparison to the control group (all P ≤ .01).

CONCLUSION

The similarity of midfoot function across time, along with differences in midfoot function in comparison to controls, suggests that TAA does not change midfoot deficits by 6 months postoperation.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Podiatrists' views and experiences of using real time clinical gait analysis in the assessment and treatment of posterior tibial tendon dysfunction

Background

Real time clinical gait analysis (RTCGA) is often incorporated as part of a general or lower limb musculoskeletal (MSK) adult patient assessment. However, it is not known if RTCGA is clinically effective as a useful outcome measure or aids in decision making. Whether there is a clinical worth in conducting RTCGA in adult MSK consultations remains controversial. The aim of this study was to provide unique insights into MSK podiatrists use and opinions of RTCGA, using Posterior Tibial Tendon Dysfunction (PTTD) as an exemplar adult condition.

Methods

A qualitative approach was employed to explore MSK podiatrists’ views and experiences of RTCGA when assessing or treating patients with PTTD. Semi-structured interviews were conducted via Skype video calls which were transcribed using an orthographic transcription method. Thematic analysis was employed to identify key meanings and report patterns within the data.

Results

Twenty nine MSK podiatrists who used RTCGA in the assessment and treatment of PTTD participated in the study. Five themes were identified as 1) RTCGA Method; 2) Working with RTCGA; 3) RTCGA uses; 4) What could aid RTCGA; 5) How RTCGA skills are acquired. This is the first known study to explore this topic of relevance to clinicians and researchers alike. Clinical observations were not only kinematic, but also included patient perceived experiences such as pain and orthotic comfort with normative kinematic reference values not perceived as important to that management goal. The most common barefoot RTCGA observations performed were the rearfoot to leg angle, medial bulge, forefoot abduction and arch integrity. However, a high amount of variation in many gait observations was noted between participants. Documentation methods also varied with a four-point scale system to grade motion and position most often employed and RTCGA was most often learnt through experience. The main barriers to performing RTCGA were clinical time and space restrictions.

Conclusion

Findings from this study have provided a view of how podiatry MSK clinicians utilise RTCGA within their practice. MSK podiatrists use RTCGA as both an outcome measure and as an aid in decision making. This implies a perceived worth in conducting RTCGA, however further work is recommended that focusses on development of a national guideline to RTCGA to be adopted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-021-00482-8.

Calcaneal lengthening osteotomy in spastic planovalgus feet

PURPOSE OF STUDY

Planovalgus deformity in cerebral palsy is disabling for the child in terms of increased energy expenditure during the gait cycle. The lever arm function of the foot is lost due to midfoot break and the achilles tendon is at a disadvantage being unable to lift the body weight during push-off. We evaluated the results of calcaneal lengthening osteotomy in such patients with clinical, radiological and gait parameters.

METHODS

17 spastic feet in a sample of 10 children were included in our study. The children were classified according to the GMFCS classification system and clinical parameters such as heel valgus and heel rise tests, radiological angles such as Talo-calcaneal angle and Talo-navicular coverage angle on AP view and Calcaneal pitch angle, calcaneus-5th metatarsal angle and talus-1st metatarsal angle on lateral view were measured. Video gait analysis was performed to observe knee progression angle in mid stance and peak knee flexion angle in mid and terminal stance.

RESULTS

Improvement was noted clinically in the heel valgus angle (preop-12.06°, postop-5.12°) and radiological parameters showed an improved coverage of the talus by navicular with simultaneous lifting of the medial longitudinal arch. Gait analysis showed decreased knee flexion trend in mid and terminal stance phase with better restoration of the knee axis.

CONCLUSION

Calcaneal lengthening osteotomy with peroneus brevis lengthening corrects almost all aspects of planovalgus deformity with an improved gait pattern without disturbing joint range of motion. It is a safe procedure for GMFCS grade 1 and 2 patients without much complications.

Gait alterations in posterior tibial tendonitis: A systematic review and meta-analysis

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) is a common and debilitating tendinopathy that can lead to a profound decrease in gait function. While the clinical diagnosis and treatment of this disorder are well described, the pathomechanics have not been adequately characterized. The purpose of this systematic review and meta-analysis is to compare foot/ankle kinematics and kinetics in patients with PTTD with healthy controls during gait.

METHODS

Relevant articles were selected thought Medline (Pubmed), Scopus, CINAHL, and Web of Science. Studies focused on foot/ankle kinematics and kinetics in patients with PTTD were involved. Articles were included if they: 1) compared patients with PTTD to healthy controls, 2) utilized kinematics or kinetics as the primary outcome measure, 3) evaluated gait tasks, and 4) were written in English.

RESULTS

Eleven articles were included in this systematic review, and 8 studies were synthesized and analyzed. Our meta-analyses indicated increased dorsiflexion and abduction of the forefoot, as well as increased plantarflexion and eversion of hindfoot for patients with PTTD during stance of walking.

CONCLUSION

Our results from the meta-analysis showed more conclusive changes in the forefoot (increased dorsiflexion and abduction) and hindfoot (increased plantarflexion and eversion) kinematics during stance of walking, which may be associated with a pathological process of PTTD. This review provides an improved understanding of gait function in patients with PTTD and preliminary knowledge for future research.

Biomechanics and Orthotic Treatment of the Adult Acquired Flatfoot

The adult acquired flatfoot deformity resulting from posterior tibial tendon dysfunction is the result of rupture of the posterior tibial tendon as well as key ligaments of the ankle and hindfoot. Kinematic studies have verified certain levels of deformity causing hindfoot eversion, lowering of the medial longitudinal arch and forefoot abduction. The condition is progressive and left untreated will cause significant disability. Bracing with ankle-foot orthoses has shown promising results in arresting progression of deformity and avoiding debilitating surgery. Various types of ankle-foot orthoses have been studied in terms of effects on gait as well as efficacy in treatment.

"I need somebody who knows about feet" a qualitative study investigating the lived experiences of conservative treatment for patients with posterior tibial tendon dysfunction

Background

Posterior tibial tendon dysfunction is a disabling, chronic, progressive tendon condition that detrimentally affects foot, ankle and lower limb function. Research suggests that posterior tibial tendon dysfunction is poorly recognised and difficult to treat. When posterior tibial tendon dysfunction is diagnosed, the clinician is faced with a weak evidence base and guidelines for the common conservative treatments.to guide their management. Moreover, there are no current evidence-based guidelines for the conservative management of posterior tibial tendon dysfunction. Emerging research suggests that posterior tibial tendon dysfunction not only has a physical impact on the patient, but it also has psychosocial impact on quality of life.Conservative treatments for posterior tibial tendon dysfunction are generally undertaken during early management. The most common are foot orthoses, exercises, bracing, lifestyle changes and injections. Quantitative evidence supporting conservative treatments for posterior tibial tendon dysfunction in relation to function, pain and patient reported outcome measures are reported in the literature.There is a paucity of qualitative research investigating the psychosocial impact of the common treatments for posterior tibial tendon dysfunction. Interpretative phenomenology is concerned with lived experience which is involves the detailed exploration of experience which is embedded within the social and temporal contexts of the lifeworld of the person. The aim of study research is to investigate the lived experience of conservative treatments for patients who have posterior tibial tendon dysfunction using Interpretative Phenomenological Analysis.

Methods

Five participants with posterior tibial tendon dysfunction were purposively recruited from a private podiatry practice and semi-structured interviews were conducted to examine their lived experiences of treatment for posterior tibial tendon dysfunction. The data for this study was collected and analysed using Interpretative Phenomenological Analysis.

Results

This research identified three superordinate themes which influenced the lived experience of treatment for these patients (i) adverse experience during the patient journey (ii) treatment burden, and (iii) negative self-concept.

Conclusion

This study highlights some of what is anecdotally known about the lived experience of treatment for patients with posterior tibial tendon dysfunction, but has never been studied in a qualitative, methodological manner. This study addresses the gap in the qualitative literature. It reveals novel aspects of the lived experience throughout the patient journey, the detrimental impact of treatment burden, loss and negative self-concept. This evidence is important because it highlights the need for a greater understanding of the psychological and social factors that can influence the lived experience of treatment for this group of patients.

Flatfoot deformity affected the kinematics of the foot and ankle in proportion to the severity of deformity

BACKGROUND

Flatfoot deformity is thought to affect gait kinematics, but the effect of flatfoot on segmental motion of the foot during gait remains unclear. Recently, multi-segmental foot models (MFMs) have been introduced for the in vivo analysis of dynamic foot kinematics. The objective of this study was to find the effect of flatfoot on segmental motion of the foot during gait in females by comparisons with age and gender controlled healthy adults.

METHODS

Thirty six symptomatic flatfeet patients (52-80 years old) and 42 symptom-free female participants without flatfoot (60-69 years old) were included in this study. According to the Meary angle (MA) on standing lateral radiograph, flatfoot patients are divided into severe (SFF, MA>20°) and moderate (MFF, 10°<MA<20°) flatfoot group. Segmental foot kinematics were evaluated using a 3D MFM of a 15-marker set (DuPont Foot Model).

RESULTS

The cadence, speed, stride length, and step width are significantly lower in flatfoot patients. ROM of sagittal and transverse plane of the hindfoot, transverse plane of the forefoot and sagittal plane of the hallux were lower in severe flatfoot group. In the SFF group, there was loss of hindfoot adduction motion during the terminal stance and pre-swing phase. In forefoot kinematics, the SFF group showed significantly supinated and abducted position throughout the gait cycle. In hindfoot kinematics, plantar flexion motion in the pre-swing phase was significantly lower in flatfoot patients in proportion to the severity of the deformity.

CONCLUSIONS

We showed that flatfoot deformity affected the kinematics of the foot and ankle in proportion to the severity of deformity. We cautiously suggest that there might be a threshold of flatfoot precluding normal foot kinematics because normal kinematic pattern of the foot might not collapse in moderate flatfoot with a Meary angle of less than 20 degrees.

Multi-segment foot models and their use in clinical populations

BACKGROUND

Many multi-segment foot models based on skin-markers have been proposed for in-vivo kinematic analysis of foot joints. It remains unclear whether these models have developed far enough to be useful in clinical populations. The present paper aims at reviewing these models, by discussing major methodological issues, and analyzing relevant clinical applications.

RESEARCH QUESTION

Can multi-segment foot models be used in clinical populations?

METHODS

Pubmed and Google Scholar were used as the main search engines to perform an extensive literature search of papers reporting definition, validation or application studies of multi-segment foot models. The search keywords were the following: 'multisegment'; 'foot'; 'model'; 'kinematics', 'joints' and 'gait'.

RESULTS

More than 100 papers published between 1991 and 2018 were identified and included in the review. These studies either described a technique or reported a clinical application of one of nearly 40 models which differed according to the number of segments, bony landmarks, marker set, definition of anatomical frames, and convention for calculation of joint rotations. Only a few of these models have undergone robust validation studies. Clinical application papers divided by type of assessment revealed that the large majority of studies were a cross-sectional comparison of a pathological group to a control population.

SIGNIFICANCE

This review suggests that there is sufficient evidence that multi-segment foot models may be successfully applied in clinical populations. Analysis of the currently available models allows users to better identify the most suitable protocol for specific clinical applications. However new models require thorough validation and assessment before being used to support clinical decisions.

Exercise for posterior tibial tendon dysfunction: a systematic review of randomised clinical trials and clinical guidelines

Objective

To systematically review all randomised clinical trials to determine the efficacy of local strengthening exercises compared with other forms of conservative management for adults with posterior tibial tendon dysfunction.

Design

Systematic review.

Data sources

Four electronic databases (Cumulative Index to Nursing and Allied Health Literature, Cochrane, Embase and PubMed) were searched up to June 2018.

Eligibility criteria for selecting studies

The study included randomised clinical trials investigating individuals with posterior tibial tendon dysfunction where local strengthening was compared with other forms of conservative management with respect to pain, function and/or physical impairment outcome measures. Standardised mean differences (SMDs) were used to compare change scores between groups and descriptors of exercise prescription assessed according to the Template for Intervention Description and Replication and the Toigo and Boutellier recommendations.

Results

3 studies (n=93) were eligible for inclusion in the review. Varying strengthening exercises were compared with stretching and foot orthoses (n=2) or no intervention (n=1). Moderate effects (SMD 0.6-1.2) were found for reducing pain and disability with eccentric strengthening in conjunction with stretching and orthoses compared with concentric exercises, stretching and orthoses combined, and stretching and orthoses alone. Evaluation of exercise prescription parameters demonstrated minimal reporting, with the only consistent parameters being the number of sets and repetitions of the exercises, and the duration of the experimental period.

Conclusion

This review demonstrates the paucity of high-quality research for the conservative management of posterior tibial tendon dysfunction, and highlights the lack of exercise prescription parameters reported in clinical trials.

Trial registration number

CRD42017076156.

Self-reported social and activity restrictions accompany local impairments in posterior tibial tendon dysfunction: a systematic review

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) is a painful, progressive tendinopathy that reportedly predominates in middle-age, overweight women. There is no evidence based guidelines that clinicians can use to guide treatment planning, which leaves clinicians to make decisions on the basis of presenting clinical impairments and self-reported pain and disability. The purpose of this systematic review was to quantify clinical impairments, pain and disability in individuals with PTTD compared with controls.

METHODS

Five databases were searched for terms referring to the posterior tibial tendon and flatfoot up to and including 11 March 2018. The systematic review was registered with PROSPERO (CRD: 42016046951). Studies were eligible if they were published in the English language and contained data on clinical impairments, pain or disability compared between participants diagnosed with PTTD and pain-free individuals. Standardised mean differences (SMDs) were calculated where possible and meta-analysis was performed when homogeneity of outcomes allowed.

RESULTS

Ten eligible studies were identified and pooled in the meta-analyses. Strong effects were revealed for poor heel rise endurance (SMD -1.52, 95% CI -2.05 to - 0.99), less forefoot adduction-inversion strength (SMD -1.19, 95% CI -1.68 to - 0.71) and lower arch height (SMD -1.76, 95% CI -2.29 to - 1.23). Compared to controls, individuals with PTTD also had more self-reported stiffness (SMD 1.45, 95% CI 0.91 to 1.99), difficulties caused by foot problems (SMD 1.42, 95% CI 0.52 to 2.33) and social restrictions (SMD1.26, 95% CI 0.25 to 2.27).

CONCLUSION

There is evidence of impaired tibialis posterior capacity and lowered arch height in individuals with PTTD compared to controls. Further to addressing the expected impairments in local tendon function and foot posture, pain, stiffness, functional limitations and social participation restrictions should be considered when managing PTTD.

Reported selection criteria for adult acquired flatfoot deformity and posterior tibial tendon dysfunction: Are they one and the same? A systematic review

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) and adult acquired flatfoot deformity (AAFD) are used interchangeably, although both suggest quite different pathological processes.

OBJECTIVE

To investigate key differences in selection criteria used for inclusion into research studies.

METHODS

An electronic database search was performed from inception to June 2016. All primary research articles with clear inclusion/diagnostic criteria for PTTD or AAFD were included in the review. All criteria were extracted and synthesised into one aggregate list. Frequencies of recurring criteria were calculated and reported for each stage of the conditions.

RESULTS

Of the potentially eligible papers, 148 (65%) did not specify inclusion/selection criteria for PTTD or AAFD and were excluded. Eligibility criteria were reported 82 times in the 80 included papers, with 69 descriptions for PTTD and 13 for AAFD. After synthesis of criteria from all papers, there were 18 key signs and symptoms. Signs and symptoms were considered to be those relating to tendon pathology and those relating to structural deformity. The total number of individual inclusion/diagnostic criteria ranged from 2 to 9. The majority of articles required signs of both tendon dysfunction and structural deformity (84% for AAFD and 81% for PTTD). Across both groups, the most frequently reported criteria were abduction of the forefoot (11.5% of total criteria used), the presence of a flexible deformity (10.2%) and difficulty performing a single leg heel raise (10.0%). This was largely the case for the PTTD articles, whereas the AAFD articles were more focused on postural issues such as forefoot abduction, medial arch collapse, and hindfoot valgus (each 16.7%).

CONCLUSION

As well as synthesising the available literature and providing reporting recommendations, this review has identified that many papers investigating PTTD/AAFD do not state condition-specific selection criteria and that this limits their clinical applicability. Key signs and symptoms of PTTD and AAFD appear similar, except in early PTTD where no structural deformity is present. We recommend that PTTD is the preferred terminology for the condition associated with signs of local tendon dysfunction with pain and/or swelling along the tendon and difficulty with inversion and/or single leg heel raise characterising stage I and difficulty with single leg heel raise and a flexible flatfoot deformity characterizing stage II PTTD. While AAFD may be useful as an umbrella term for acquired flatfoot deformities, the specific associated aetiology should be reported in studies to aid consolidation and implementation of research into practice.

TRIAL REGISTRATION

Prospero ID: 42016046943.

Non-surgical treatment of pain associated with posterior tibial tendon dysfunction: study protocol for a randomised clinical trial

Background

Symptoms associated with pes planovalgus or flatfeet occur frequently, even though some people with a flatfoot deformity remain asymptomatic. Pes planovalgus is proposed to be associated with foot/ankle pain and poor function. Concurrently, the multifactorial weakness of the tibialis posterior muscle and its tendon can lead to a flattening of the longitudinal arch of the foot. Those affected can experience functional impairment and pain. Less severe cases at an early stage are eligible for non-surgical treatment and foot orthoses are considered to be the first line approach. Furthermore, strengthening of arch and ankle stabilising muscles are thought to contribute to active compensation of the deformity leading to stress relief of soft tissue structures. There is only limited evidence concerning the numerous therapy approaches, and so far, no data are available showing functional benefits that accompany these interventions.

Methods

After clinical diagnosis and clarification of inclusion criteria (e.g., age 40–70, current complaint of foot and ankle pain more than three months, posterior tibial tendon dysfunction stage I & II, longitudinal arch flattening verified by radiography), sixty participants with posterior tibial tendon dysfunction associated complaints will be included in the study and will be randomly assigned to one of three different intervention groups: (i) foot orthoses only (FOO), (ii) foot orthoses and eccentric exercise (FOE), or (iii) sham foot orthoses only (FOS). Participants in the FOO and FOE groups will be allocated individualised foot orthoses, the latter combined with eccentric exercise for ankle stabilisation and strengthening of the tibialis posterior muscle. Participants in the FOS group will be allocated sham foot orthoses only. During the intervention period of 12 weeks, all participants will be encouraged to follow an educational program for dosed foot load management (e.g., to stop activity if they experience increasing pain). Functional impairment will be evaluated pre- and post-intervention by the Foot Function Index. Further outcome measures include the Pain Disability Index, Visual Analogue Scale for pain, SF-12, kinematic data from 3D-movement analysis and neuromuscular activity during level and downstairs walking. Measuring outcomes pre- and post-intervention will allow the calculation of intervention effects by 3×3 Analysis of Variance (ANOVA) with repeated measures.

Discussion

The purpose of this randomised trial is to evaluate the therapeutic benefit of three different non-surgical treatment regimens in participants with posterior tibial tendon dysfunction and accompanying pes planovalgus. Furthermore, the analysis of changes in gait mechanics and neuromuscular control will contribute to an enhanced understanding of functional changes and eventually optimise conservative management strategies for these patients.

Trial registration

ClinicalTrials.gov Protocol Registration System: ClinicalTrials.gov ID NCT01839669

Segmental motion of forefoot and hindfoot as a diagnostic tool

Segmental motions derived from non-invasive motion analysis are being used to investigate the intrinsic functional behavior of the foot and ankle in health and disease. The goal of this research was to examine the ability of a generic segmented model of the foot to capture and differentiate changes in internal skeletal kinematics due to neuromuscular disease and/or trauma. A robotic apparatus that reproduces the kinematics and kinetics of gait in cadaver lower extremities was employed to produce motion under normal and aberrant neuromuscular activation patterns of tibialis posterior and/or tibialis anterior. Stance phase simulations were conducted on 10 donor limbs while recording three-dimensional kinematic trajectories of (1) skin-mounted markers used clinically to construct segmented foot models, and (2) bone-mounted marker clusters to capture actual internal bone motion as the gold standard for comparison. The models constructed from external marker data were able to differentiate the kinematic behaviors elicited by different neuromuscular conditions in a manner similar to that using the bone-derived data. Measurable differences between internal and externally measured kinematics were small, variable and random across the three axes of rotation and neuromuscular conditions, with a tendency toward more differences noted during early and late stance. Albeit slightly different, three-dimensional motion profiles of the hindfoot and forefoot segments correlated well with internal skeletal motion under all neuromuscular conditions, thereby confirming the utility of measuring segmental motions as a valid means of clinical assessment.

Clinical outcomes and static and dynamic assessment of foot posture after lateral column lengthening procedure

BACKGROUND

Lateral column lengthening (LCL) has been shown to radiographically restore the medial longitudinal arch. However, the impact of LCL on foot function during gait has not been reported using validated clinical outcomes and gait analysis.

METHODS

Thirteen patients with a stage II flatfoot who had undergone unilateral LCL surgery and 13 matched control subjects completed self-reported pain and functional scales as well as a clinical examination. A custom force transducer was used to establish the maximum passive range of motion of first metatarsal dorsiflexion at 40 N of force. Foot kinematic data were collected during gait using 3-dimensional motion analysis techniques.

RESULTS

Radiographic correction of the flatfoot was achieved in all cases. Despite this, most patients continued to report pain and dysfunction postoperatively. Participants post LCL demonstrated similar passive and active movement of the medial column when we compared the operated and the nonoperated sides. However, participants post LCL demonstrated significantly greater first metatarsal passive range of motion and first metatarsal dorsiflexion during gait than did controls (P < .01 for all pairwise comparisons).

CONCLUSION

Patients undergoing LCL for correction of stage II adult-acquired flatfoot deformity experience mixed outcomes and similar foot kinematics as the uninvolved limb despite radiographic correction of deformity. These patients maintain a low arch posture similar to their uninvolved limb. The consequence is that first metatarsal movement operates at the end range of dorsiflexion and patients do not obtain full hindfoot inversion at push-off. Longitudinal data are necessary to make a more valid comparison of the effects of surgical correction measured using radiographs and dynamic foot posture during gait.

LEVEL OF EVIDENCE

Level III, comparative series.

In vitro analysis of muscle activity illustrates mediolateral decoupling of hind and mid foot bone motion

Activity of the extrinsic ankle-foot muscles is typically described for the whole foot. This study determines if this muscle activity is also confirmed for individual foot segments defined in multi-segment foot models used for clinical gait analysis. Analysis of the individual bone motion can identify functional complexes within the foot and evaluates the influence of an altered foot position on muscle activity. A custom designed and built gait simulator incorporating pneumatic actuators is used to control the muscle force of six muscle groups in cadaveric feet. Measurements were performed in three static postures in which individual muscle force was incrementally changed. The motion of four bone embedded LED-clusters was measured using a Krypton motion capture system and resulting motion of calcaneus, talus, navicular and cuboid was calculated. Results indicate that primary muscle activity at bone level corresponds with that described for the whole foot. Secondary activity is not always coherent for bones within one segment: decoupling of the movement of medial and lateral foot bones is documented. Furthermore, secondary muscle activity can alter according to foot position. The observed medio-lateral decoupling of the foot bones dictates the need to extend some of the multi-segment foot models currently used in clinical gait analysis.

Biomechanical and clinical factors related to stage I posterior tibial tendon dysfunction

STUDY DESIGN

Case control.

OBJECTIVES

To investigate differences in arch height, ankle muscle strength, and biomechanical factors in individuals with stage I posterior tibial tendon dysfunction (PTTD) in comparison to healthy individuals.

BACKGROUND

PTTD is a progressive condition, so early recognition and treatment are essential to help delay or reverse the progression. However, no previous studies have investigated stage I PTTD, and no single study has measured static anatomical structure, muscle strength, and gait mechanics in this population.

METHODS

Twelve individuals with stage I PTTD and 12 healthy, age- and gender-matched control subjects, who were engaged in running-related activities, participated in this study. Measurements of arch height index, maximum voluntary ankle invertor muscle strength, and 3-dimensional rearfoot and medial longitudinal arch kinematics during walking were obtained.

RESULTS

The runners with PTTD demonstrated significantly lower seated arch height index (P = .02) and greater (P = .03) and prolonged (P = .05) peak rearfoot eversion angle during gait, compared to the healthy runners. No differences were found in standing arch height index values (P = .28), arch rigidity index (P = .06), ankle invertor strength (P = .49), or peak medial longitudinal arch values (P = .49) between groups.

CONCLUSION

The increased foot pronation is hypothesized to place greater strain on the posterior tibialis muscle, which may partially explain the progressive nature of this condition.

Women with posterior tibial tendon dysfunction have diminished ankle and hip muscle performance

STUDY DESIGN

Controlled laboratory study using a cross-sectional design.

OBJECTIVES

To characterize ankle and hip muscle performance in women with posterior tibial tendon dysfunction (PTTD) and compare them to matched controls. We hypothesized that ankle plantar flexor strength, and hip extensor and abductor strength and endurance, would be diminished in women with PTTD and this impairment would be on the side of dysfunction.

BACKGROUND

Individuals with PTTD demonstrate impaired walking abilities. Walking gait is strongly dependent on the performance of calf and hip musculature.

METHODS

Thirty-four middle-aged women (17 with PTTD) participated. Ankle plantar flexor strength was assessed with the single-leg heel raise test. Hip muscle performance, including strength and endurance, were dynamometrically measured. Differences between groups and sides were assessed with a mixed-model analysis of variance.

RESULTS

Females with PTTD performed significantly fewer single-leg heel raises and repeated sagittal and frontal plane non-weight-bearing leg lifts, and also had lower hip extensor and abductor torques than age-matched controls. There were no differences between sides for hip strength and endurance measures for either group, but differences between sides in ankle strength measures were noted in both groups.

CONCLUSION

Women with PTTD demonstrated decreased ankle and hip muscle performance bilaterally.