A Passive Polycentric Mechanism to Improve Active Mediolateral Balance in Prosthetic Walking

Prosthetic legs are typically passive systems without active ankle control, restricting mediolateral balancing to a hip strategy. Resulting balance control impairments for persons with a lower extremity amputation may be mitigated by increasing hip strategy effectiveness, in which relatively small hip moments of force are adequate for mediolateral balancing. To increase hip strategy effectiveness we have developed a prosthetic leg prototype based on the Peaucellier mechanism, the Sideways Balance Mechanism (SBM). This polycentric mechanism adds a frontal plane degree of freedom, reducing mediolateral body displacements. Adding a passive joint alone introduces instability, in which mediolateral body rotation leads to CoM height loss, ultimately resulting in a fall. The SBM however provides stability typically absent by lengthening under rotation, thereby compensating for CoM height loss. By allowing for both foot rotation (in-/eversion), and increased mediolateral ground reaction force the SBM increases hip strategy effectiveness. We aimed to provide proof of principle that the SBM can improve active mediolateral balance control in prosthetic walking by increasing hip strategy effectiveness compared to a typical set-up. Comparison between a typical set-up and the SBM showed an increased mediolateral ground reaction force at equal hip moments of force for a 2D forwards dynamics computer simulation, and a reduced hip moment of force at equal mediolateral ground reaction force for a case study. Results validate increased hip strategy effectiveness of the SBM compared to a typical set-up, providing proof of principle that adding an SBM to a prosthetic set-up improves mediolateral balance control in prosthetic walking.

Prevalence and factors associated with musculoskeletal complaints and disability in individuals with brachial plexus injury: a cross-sectional study

PURPOSE

(1) To determine the prevalence of musculoskeletal complaints (MSCs) in the non-affected bodily structures in individuals with brachial plexus injury (BPI) and (2) to analyse factors associated with MSCs and disability.

METHODS

Survey among individuals with BPI and a control group. Multivariable logistic and linear regression analyses were used to identify factors associated with MSCs or disability.

RESULTS

Forty-nine percent of individuals (34/70) with BPI experienced MSC, which was not significantly different from controls (35%, n = 40/113). Complaints were most often located in high back (OR  =  3.6) or non-affected limb (OR  =  2.2) or neck (OR  =  2.1). Greater disability was associated with the presence of MSC in individuals with BPI (OR  =  1.1, 95% confidence interval (95% CI) = 1.0; 1.1). Those with no or a low level of education (B = -10.2, 95% CI = -19.6; -1.4), a history of nerve surgery (B = 11.1, 95% CI = -0.2; 20.9), and moderately affected active range of motion (AROM) of the affected limb (B = 20.7, 95% CI  =  8.8; 31.0) experienced most disability. Individuals with severely affected AROM showed a wide range of experienced disability.

CONCLUSIONS

Clinicians should be aware that almost half of individuals with BPI have MSCs in the non-affected bodily structures, which was associated with increased disability.Implications for rehabilitationMusculoskeletal complaints of the non-affected limb, back and neck are common among individuals with brachial plexus injury, and are associated with more disability.Disability was associated with loss of active range of motion (AROM) in the affected limb, although there was a wide variation in experienced disability among individuals with no or a very limited AROM.

Frontal plane roll-over analysis of prosthetic feet

In prosthetic walking mediolateral balance is compromised due to the lack of active ankle control, by moments of force, in the prosthetic limb. Active control is reduced to the hip strategy, and passive mechanical stability depends on the curvature of the prosthetic foot under load. Mediolateral roll-over curvatures of prosthetic feet are largely unknown. In this study we determined the mediolateral roll-over characteristics of various prosthetic feet and foot-shoe combinations. Characteristics were determined by means of an inverted pendulum-like apparatus. The relationship between the centre of pressure (CoP) and the shank angle was measured and converted to roll-over shape and effective radius of curvature. Further, hysteresis (i.e., lagging in CoP displacement due to material compliance or slip) at vertical shank angle was determined from the hysteresis curve. Passive mechanical stability varied widely, though all measured foot-shoe combinations were relatively compliant. Mediolateral motion of the CoP ranged between 4 mm and 40 mm, thereby remaining well within each foot's physical width. Derived roll-over radii of curvature are also small, with an average of 102 mm. Hysteresis ranges between 20% and 115% of total CoP displacement and becomes more pronounced when adding a shoe. This may be due to slipping of the foot core in its cosmetic cover, or the foot in the shoe. Slip may be disadvantageous for balance control by limiting mediolateral travel of the CoP. It may therefore be clinically relevant to eliminate mediolateral slip in prosthetic foot design.

Effect of different forefoot rocker radii on lower-limb joint biomechanics in healthy individuals

INTRODUCTION

Previous studies showed that rocker shoes with a stiff forefoot rocker profile significantly reduce peak plantar flexion moment at the ankle (PFM) and peak ankle dorsiflexion (DF). Both parameters are related to Achilles tendon and Plantar Fascia unloading. The shape of an outsole with a forefoot rocker is described with multiple rocker design parameters. The aim of this research is, to determine the relation between different forefoot rocker radii on peak DF and peak PFM at a self-selected walking speed.

METHODS

10 participants walked in standard shoes and three experimental pairs of shoes with different forefoot rocker radii. Lower extremity kinematics and kinetics were collected while walking on an instrumented treadmill at preferred walking speed and analysed with Statistical Parametric Mapping (SPM) (α = .05; post-hoc α = .05/6).

RESULTS

Peak value analyses showed significant decreases in peak DF, peak PFM, and peak ankle power generation for the rocker conditions. No relevant significant differences were found in spatio-temporal parameters and total work at the ankle joint. SPM showed a significant decrease (% gait cycle) in DF (40-69 %), PFM (7-15 %; 41-68 %; 69-81 %), ankle power (10-15 %; 32-51 %; 55-64 %; 64-67 %; 72-80 %) and foot-to-horizontal angle (FHA) (0-4 %; 40-62 %; 92-100 %) and an increased shank-to-vertical angle (SVA) (44-84 %) for the rocker conditions.

CONCLUSION

The results of this study suggest that rocker shoes with a proximally placed apex significantly reduce DF and PFM during the third rocker compared with control shoes. This effect is mainly explained by a change in the FHA. Smaller radii cause the largest reductions in DF and PFM, so therefore, a uniform standardisation of the forefoot rocker radius is essential.

A toolkit for prosthetists and orthotists to facilitate progress in professional communication over the next 50 years

BACKGROUND

In this celebratory issue of Prosthetics and Orthotics International, we review professional communication skills in the field of prosthetics and orthotics.

OBJECTIVE

We aim to reflect on communication skills in the past 50 years, to discuss developments in the coming 50 years, and to create a toolkit and research agenda to facilitate progress in professional communication in the next 50 years.

RESULTS

Despite being a key area in prosthetics and orthotics training programmes, we found no studies on professional communication with an experimental design published in Prosthetics and Orthotics International. As an alternative, we provide clinical reflections on the changes in professional communication in the past 50 years, and we discuss questionnaire-based and qualitative studies that provide evidence for the importance of communication in pedorthic footwear provision. In the coming 50 years, professional communication in the field of prosthetics and orthotics may be impacted by aging populations, global mobility, information technology, technological advances and emphasis on prevention. We discuss each of these topics. To facilitate progress in professional communication, we have created a toolkit with resources for prosthetics and orthotics professionals, prosthetics and orthotics students and other interested professionals.

CONCLUSIONS

We hope this toolkit will inspire others to use, extend and implement it in their daily practice. As a research agenda, we strongly recommend undertaking research on interventions to improve professional communication and to study its effect on clinically meaningful outcomes.

Effect of awareness of being monitored on wearing of orthopaedic footwear

OBJECTIVE

To investigate the effect of awareness of being monitored on wearing time and adherence to wearing orthopaedic footwear. Quantitative assessment of wearing time was made using direct measurement with temperature sensors during the first 3 months after provision of footwear.

DESIGN

Randomized controlled trial.

INTERVENTION

Awareness that the temperature sensor is used for measuring wearing time.

METHODS

All 55 participants had a temperature sensor built into the medial arch of the left insole of their orthopaedic footwear. Participants were assigned randomly to either an "awareness group" (n = 25, mean age 67 years) and knew they were being monitored for wearing time, or a "no awareness group" (n = 30, mean age 65 years) and only knew their shoe temperature was being measured. Differences were assessed with a linear mixed model.

RESULTS

Mean (standard deviation; SD) wearing time in the intervention group was 7.32 h/day (SD 4.2), and 6.11 h/day (SD 4.1) in the control group (p = 0.017). A significant interaction effect was found between awareness and pathology group on wearing time (p = 0.036). The difference was especially large (7.0 (SD 4.7) vs 2.4 (SD 2.2) h/day) in the subgroup of people with diabetes.

CONCLUSION

Awareness of being monitored increases wearing time and wearing of orthopaedic footwear.

Mechanical Noise Improves the Vibration Perception Threshold of the Foot in People With Diabetic Neuropathy

BACKGROUND

Mechanical noise may improve somatosensation at the dorsal side of the foot, but the effect at the plantar side of the foot, the side most at risk for foot ulceration, is unknown. Moreover, techniques used in research so far have several problems that limit applicability in daily practice. Piezoelectric actuators may provide mechanical noise with better clinical applicability. We assessed the effects of piezoelectric actuators generating mechanical noise on the vibration perception threshold (VPT) at the plantar side of the foot in people with diabetic neuropathy.

METHODS

Double-blind within-subjects design in a controlled laboratory setting including participants with diabetic neuropathy (N = 40; 18 male; mean age 69.6 years; mean duration of diabetes 14.1 years; mean BMI 30.5). VPT was measured at three plantar foot locations with and without mechanical noise applied via piezoelectric actuators.

RESULTS

Mechanical noise improved VPT at metatarsophalangeal joint (MTP) 1 (left 39.3V vs 43.5V; right 39.0 vs 42.6 V), MTP5 (left 37.5V vs 41.7V; right 34.5V vs 40.8V) and the heel (left 40.0V vs 44.0V; right 39.3V vs 41.0V), all P < .001.

CONCLUSIONS

Mechanical noise improves VPT at the plantar side of the foot in people with diabetic neuropathy. This is an important step for further development of insoles using mechanical noise that may have the potential to improve VPT and decrease the risk of foot ulceration.

Development of an Ankle-Foot Orthosis That Provides Support for Flaccid Paretic Plantarflexor and Dorsiflexor Muscles

ADJUST, a novel ankle-foot orthosis (AFO) that we have developed, allows the ankle a normal range of motion (ROM) while providing support for flaccid ankle-muscle paresis. It consists of two leaf-spring hinges that independently control plantarflexion and dorsiflexion stiffness. To evaluate whether ADJUST meets the minimum mechanical requirements, we quantified its ankle ROM and stiffness. To evaluate whether it meets the minimum ankle kinematic and kinetic goals for normal gait, a patient with both plantarflexor and dorsiflexor paralysis used it, and his own AFO, to walk. When fitted with stiff springs, ADJUST met all requirements and goals. During the stance and the swing phases, ankle ROM was within the normal range when ADJUST was fitted with stiff springs. Ankle ROM during stance was outside the normal range both with the patient's own AFO and with ADJUST when it was fitted with flexible springs. Power at the ankle met the minimum goal but was lower with ADJUST than with the patient's own AFO. The optimal stiffness configuration that would result in a higher power at the ankle with a normal ankle ROM was not reached for this patient. Walking with ADJUST seems feasible and could be profitable in patients with flaccid ankle muscle paresis.

Validity and feasibility of a temperature sensor for measuring use and non-use of orthopaedic footwear

OBJECTIVE

Adherence is a prerequisite for the effectiveness of orthopaedic footwear. The aim of this study is to assess the validity of a new temperature sensor for objective assessment of footwear use and non-use.

DESIGN

Observational study.

METHODS

The validity of a temperature sensor (Orthotimer, Balingen, Germany) to discriminate between time periods of use and non-use of footwear over a period of 48 h was assessed using 3 algorithms, in 10 healthy participants (mean age 32.8 years (standard deviation (SD) 14.1 years)). Footwear use measured with the sensor was compared with a reference standard, footwear use measured with a time-lapse sports camera secured to the shoe.

MAIN OUTCOME MEASURE

Hours of footwear use.

RESULTS

Mean footwear use measured with the camera was 8.10 (SD 2.46) h per day. Mean footwear uses measured with the sensor and calculated with the 3 algorithms were 8.16 (SD 2.37), 8.86 (SD 2.48) and 4.91 (SD 3.17) h per day for the Groningen algorithm, algorithm-25, and algorithm-29, respectively. The correlation between footwear use assessed with the camera and with the sensor was: rGroningen = 0.995, ralg25 = 0.919 and ralg29 = 0.680).

CONCLUSION

The temperature sensor is a valid instrument to measure footwear use and non-use when using the Groningen algorithm.

A user-centered qualitative study on experiences with ankle-foot orthoses and suggestions for improved design

BACKGROUND

Improving ankle-foot orthosis design can best be done by implementing a user-centered approach.

OBJECTIVE

To provide insight into the ideas of ankle-foot orthosis users with flaccid ankle muscle paresis on the importance of activities and suggestions for an improved ankle-foot orthosis design.

STUDY DESIGN

A focus-group discussion with eight ankle-foot orthosis users (57 ± 5 years, 50% female).

METHODS

Main inclusion criteria were as follows: ⩾18 years, unable to stand on tip-toe and unable to lift toes. Main exclusion criterion was spasticity of lower extremity muscles. Transcribed data were coded according to the International Classification of Functioning, Disability and Health. Thematic analysis with inductive approach was chosen to order and interpret codes.

RESULTS

Ankle-foot orthosis users ranked walking the most important activity followed by sitting down/standing up from a chair. Their opinion was that ankle-foot orthoses facilitate walking and standing. Ankle-foot orthosis users suggested that an improved ankle-foot orthosis design should balance between stability and flexibility.

CONCLUSION

Current ankle-foot orthoses facilitate walking which was the most important activity according to ankle-foot orthosis users. An improved ankle-foot orthosis design should enable walking and should optimize between stability and flexibility dependent on the activity and the paresis severity. Clinical relevance Experienced users of ankle-foot orthosis agreed that matching ankle-foot orthosis functions to daily-life activities is a trade-off between stability and flexibility. An improved ankle-foot orthosis design should at least enable level walking.

Diabetic Foot Australia guideline on footwear for people with diabetes

Background

The aim of this paper was to create an updated Australian guideline on footwear for people with diabetes.

Methods

We reviewed new footwear publications, (inter)national guidelines, and consensus expert opinion alongside the 2013 Australian footwear guideline to formulate updated recommendations.

Result

We recommend health professionals managing people with diabetes should: (1) Advise people with diabetes to wear footwear that fits, protects and accommodates the shape of their feet. (2) Advise people with diabetes to always wear socks within their footwear, in order to reduce shear and friction. (3) Educate people with diabetes, their relatives and caregivers on the importance of wearing appropriate footwear to prevent foot ulceration. (4) Instruct people with diabetes at intermediate- or high-risk of foot ulceration to obtain footwear from an appropriately trained professional to ensure it fits, protects and accommodates the shape of their feet. (5) Motivate people with diabetes at intermediate- or high-risk of foot ulceration to wear their footwear at all times, both indoors and outdoors. (6) Motivate people with diabetes at intermediate- or high-risk of foot ulceration (or their relatives and caregivers) to check their footwear, each time before wearing, to ensure that there are no foreign objects in, or penetrating, the footwear; and check their feet, each time their footwear is removed, to ensure there are no signs of abnormal pressure, trauma or ulceration. (7) For people with a foot deformity or pre-ulcerative lesion, consider prescribing medical grade footwear, which may include custom-made in-shoe orthoses or insoles. (8) For people with a healed plantar foot ulcer, prescribe medical grade footwear with custom-made in-shoe orthoses or insoles with a demonstrated plantar pressure relieving effect at high-risk areas. (9) Review prescribed footwear every three months to ensure it still fits adequately, protects, and supports the foot. (10) For people with a plantar diabetic foot ulcer, footwear is not specifically recommended for treatment; prescribe appropriate offloading devices to heal these ulcers.

Conclusions

This guideline contains 10 key recommendations to guide health professionals in selecting the most appropriate footwear to meet the specific foot risk needs of an individual with diabetes.

Effects of flexible and rigid rocker profiles on in-shoe pressure

Rocker profiles are commonly used in the prevention of diabetic foot ulcers. Rockers are mostly stiffened to restrict toe plantarflexion to ensure proper offloading. It is also described that toe dorsiflexion should be restricted. However, the difference in effect on plantar pressure between rigid rockers that restrict this motion and flexible rockers that do not is unknown. In-shoe plantar pressure data were collected for a control shoe and the same shoe with rigid and flexible rockers with the apex positioned at 50% and 60%. For 29 healthy female adults peak plantar pressure (PP), maximum mean pressure (MMP) and force-time integral (FTI) were determined for seven regions of the foot. Generalized estimate equation was used to analyse the effect of the different shoes on the outcome measures for these regions. Compared to the control shoe a significant increase of PP and FTI was found at the first toe for both rigid rockers and the flexible rocker with the apex positioned at 60%, while MMP was significantly increased in rockers with an apex position of 60% (p<0.001). PP at the first toe was significantly lower in flexible rockers when compared to rigid rockers (p<0.001). For both central and lateral forefoot PP and MMP were significantly more reduced in rigid rockers (p<0.001), while for the medial forefoot no differences were found. The use of rigid rockers results in larger reductions of forefoot plantar pressures, but in worse increase of plantar pressures at the first toe compared to rockers that allow toe dorsiflexion.

Communication techniques for improved acceptance and adherence with therapeutic footwear

BACKGROUND AND AIM

Clients' acceptance and adherence with orthoses can be influenced by a clinician's communication skills. In this clinical note, we describe two communication techniques, in the context of therapeutic footwear.

TECHNIQUE

Person-centred communication involves engaging with and listening to the attitudes of the client towards their condition, as well as discussing acceptance and expectations, in a structured consultation. Building a relationship is crucial and requires clients to feel heard and understood. An important influence on the acceptance and adherence is that a client makes a conscious decision to receive their device. This active receipt can be facilitated through shared decision making, wherein clinicians give clear, relevant and meaningful examples, based on clinical evidence, and ensure this is understood.

DISCUSSION

Two communication techniques for clinicians providing therapeutic footwear are described. These can be adapted for use with provision of other assistive technologies to improve client acceptance and adherence. Clinical relevance Small changes in how clinicians communicate to their clients in daily practice can have a big influence on the subsequent acceptance and adherence with therapeutic footwear and indeed other prescribed assistive technologies.

Age-related differences in women's foot shape

PURPOSE

Describe age-related differences in women's foot shape using a wide range of measurements and ages.

STUDY DESIGN

Cross-sectional, observational study.

MAIN OUTCOME MEASUREMENTS

Six foot-shape measurements of each foot: foot lengths, ball widths, ball circumferences, low instep circumferences, high instep circumferences, and heel instep circumference.

RESULTS

168 women from 20 to over 80 years of age, divided into seven age categories, were included. Older women had significantly greater foot-shape measurements, even after adjusting for Body Mass Index. Ball widths increased 3.1-4.0mm per decade, ball circumferences 5.6-7.4mm per decade, high instep circumferences 0.4-4.8mm per decade, and heel instep circumferences 1.8-1.9mm per decade. Ball widths, ball circumferences, and left high instep circumference plateaued in the 70-75 years-of-age category, and decreased in the oldest age category. For low instep circumference, age did not prevail significantly over Body Mass Index. Foot length was not associated with age.

CONCLUSION

This study described women's progressive foot-shape changes with age. The findings provide a better understanding of foot-shape changes, mainly found in the forefoot. It demonstrates that for a good fit, shoe design for older adults and for younger adults should differ.

A review of salient elements defining team collaboration in paediatric rehabilitation

Objective: To explicate the complex process of team collaboration and identify salient elements of team collaboration in paediatric rehabilitation.

Data sources: After an initial search to define key features of team collaboration a systematic search on team collaboration and the key features was executed to identify salient elements. The systematic search was carried out in Index Medicus (MEDLINE), Educational Resource Information Clearinghouse (ERIC) and American Psychological Association (Psyc INFO) covering the period from January 1993 to December 2004.

Review methods: Based on title and abstract relevant publications were identified and qualitatively assessed by two reviewers. To facilitate the interpretation of the salient elements, the articles were also classified according to the criteria ‘participants and setting’ and ‘research method’.

Results: Of the total of 930 identified publications 28 studies proved eligible and were subsequently assessed. The evaluation yielded 29 salient elements defining five key features of team collaboration (i.e. communication, decision making, goal setting, organization and team process). Parent involvement proved to play a dominant role and was mentioned in relation to all five features.

Conclusions: Based on the results, rather than an underlying element, it is proposed to consider parent involvement as the sixth feature of team collaboration. The 29 distinctive elements of teamwork could be useful as a guideline and checklist for empirical studies and may help enhance multidisciplinary collaboration in paediatric care. However, additional exploratory research focusing on the way these elements interact with each other and the key features and whether they facilitate or restrict team collaboration is warranted.

Family-centred care in family-specific teams

Objective: To evaluate the perceptions and views of parents and rehabilitation and special education professionals on the family-centredness of care delivered and received.

Design: Descriptive study with comparison of ratings in family-specific teams.

Setting: Five paediatric facilities in the Netherlands.

Subjects: Parents of children with cerebral palsy and professionals providing their children's rehabilitation and educational services.

Main measures: The Dutch Measure of Processes of Care for families (MPOC-NL) and the Measure of Processes of Care for service providers (MPOC-SP). Data were collected and analysed per family.

Results: In total 38 MPOC-NLs and 204 MPOC-SPs were returned. The family-specific team analysis of importance ratings yielded significant differences ( P < 0.05) on all domains between parents, rehabilitation professionals and special education professionals. For Enabling and partnership ( P < 0.01) and Specific information about the child ( P < 0.01), parents considered the behaviours to be significantly more important than rehabilitation professionals. The problem-score analyses showed that in all domains a considerable number of parents (19—38%) did not receive the care they deemed important.

Conclusion: Family-specific analyses of MPOC importance ratings revealed differences in attitudes towards importance of specific care behaviours of team members, which subsequently may have caused the relatively high incidence of parents not receiving the care they deemed important. This underscores the need to explore and attune opinions on what constitutes proper service delivery.

An open socket technique for through-knee amputations in relation to skin problems of the stump: an explorative study

Objective: To compare the conventional socket for through-knee amputees with an open socket system for skin problems and other relevant items.

Design: All data were collected during three visits to the prosthetic clinic. At the second visit the conventional socket was replaced by the open socket. The use of both socket types was evaluated with a questionnaire and stump inspection.

Setting: The subjects were evaluated at the Rehabilitation Centre, St Maartenskliniek, Nijmegen, the Netherlands.

Subjects: Twenty subjects with a unilateral through-knee amputation were included and 13 subjects had a trial with the open socket.

Results: There is a significant decrease of hyperhydrosis when wearing the open socket, there is no significant decrease in skin irritation or ulcers. The open socket also gives more comfort in sitting position.

Conclusion: A further trial is needed in a selected group of prosthesis users among through-knee amputees to establish the long-term acceptance and benefits of the prosthesis with an open socket.

Distinguishing theories of dysfunction, treatment and care. Reflections on ‘Describing rehabilitation interventions’

Background: An editorial by Wade (Clinical Rehabilitation 2005; 19: 811-18. suggested a method for describing rehabilitation interventions.

Objective: To review the editorial critically, and to suggest a more complete theory.

Editorial: The editorial develops a model identifying factors that should be considered when analysing a complex rehabilitation problem, and provides a high-level description of the rehabilitation process. It explicitly does not address theories of behaviour change.

New ideas: Three additional theoretical models are needed. The first considers the mechanisms that link the factors identified in Wade's model. For example how does self-esteem (in personal context) actually influence activity performance? This is a theory of dysfunction. The second needs to discuss how treatments alter their target. For example how does cognitive behavioural therapy alter pain perception and/or alter activity performance? This is a theory of treatment. It may be related to the theory of dysfunction. The third, which is less certain, needs to consider the process of giving support (maintaining the status quo). For example, how should one offer continuing opportunities for meaningful social role performance to someone with major cognitive losses? This is a theory of care.

Conclusion: The two models that Wade integrated in his conceptual framework (the World Health Organization's International Classification of Functioning (WHO ICF) and the rehabilitation process) should primarily be considered as descriptive in character. Theories are still needed to understand how activity limitation arises and how treatments alter activity limitation, and possibly how a patient is supported to maintain a certain level of activity.

Staying in dynamic balance on a prosthetic limb: A leg to stand on?

With the loss of a lower limb, amputees lack the active muscle empowered control of the ankle that is important for balance control. We examined single-leg stance on prosthesis vs. sound limb balancing on narrow ridges in transtibial amputees. When balancing on the prosthetic limb, the lateral displacement of the center of pressure was reduced and was compensated by an increase in counter-rotation. We show that single-leg stance on a prosthetic limb can be compared to balancing on a narrow ridge. Standing on a prosthetic limb involves the same balance mechanisms as balancing on narrow ridges of 40-mm to 20-mm width. Yet, the ability to balance on a narrow ridge with the sound limb was only a weak predictor for an amputee's ability to stand on the prosthetic limb. Balancing in single-leg stance on a prosthetic limb is not a common activity. The ability to compensate with the sound limb may therefore be functionally more important than the ability to stay in dynamic balance on the prosthetic limb.

Exergames for unsupervised balance training at home: A pilot study in healthy older adults

Exercise videogames (exergames) are gaining popularity as tools for improving balance ability in older adults, yet few exergames are suitable for home-based use. The purpose of the current pilot study was to examine the effects of a 6-week unsupervised home-based exergaming training program on balance performance. Ten community dwelling healthy older adults (age: 75.9 ± 7.2 years) played a newly developed ice skating exergame for six weeks at home. In the game, the speed and direction of a virtual ice skater on a frozen canal were controlled using lateral weight shifts, which were captured using Kinect. Sway characteristics during quiet standing in eyes open (EO), eyes closed (EC) and dual task (DT) conditions were assessed in time and frequency domain before, and after two, four and six weeks of training. Balance was also evaluated using the narrow ridge balance test (NRBT). Multilevel modeling was applied to examine changes in balance ability. Participants played 631 (± 124)min over the intervention period and no subjects dropped out. Balance in terms of sway characteristics improved on average by 17.4% (EO) and 23.3% (EC) after six weeks of training (p<0.05). Differences in rate of improvement (p<0.05) were observed between participants. No intervention effects were found for quiet standing in DT conditions and on the NRBT. In conclusion, the pilot study showed that unsupervised home-based exergaming is feasible in community dwelling older adults, but also that participants do not benefit equally from the program, thereby emphasizing the need for more personalized exergame training programs.

A systematic review of instruments for assessment of capacity in activities of daily living in children with developmental co-ordination disorder

Children with developmental co-ordination disorder (DCD) face evident motor difficulties in activities of daily living (ADL). Assessment of their capacity in ADL is essential for diagnosis and intervention, in order to limit the daily consequences of the disorder. The aim of this study is to systematically review potential instruments for standardized and objective assessment of children's capacity in ADL, suited for children with DCD. As a first step, databases of MEDLINE, EMBASE, CINAHL and PsycINFO were searched to identify studies that described instruments with potential for assessment of capacity in ADL. Second, instruments were included for review when two independent reviewers agreed that the instruments (1) are standardized and objective; (2) assess at activity level and comprise items that reflect ADL; and (3) are applicable to school-aged children that can move independently. Out of 1507 publications, 66 publications were selected, describing 39 instruments. Seven of these instruments were found to fulfil the criteria and were included for review: the Bruininks-Oseretsky Test of Motor Performance-2 (BOT2); the Do-Eat (Do-Eat); the Movement Assessment Battery for Children-2 (MABC2); the school-Assessment of Motor and Process Skills (schoolAMPS); the Tuffts Assessment of Motor Performance (TAMP); the Test of Gross Motor Development (TGMD); and the Functional Independence Measure for Children (WeeFIM). As a third step, for the included instruments, suitability for children with DCD was discussed based on the ADL comprised, ecological validity and other psychometric properties. We concluded that current instruments do not provide comprehensive and ecologically valid assessment of capacity in ADL as required for children with DCD.

Psychometric properties of the DCDDaily-Q: a new parental questionnaire on children's performance in activities of daily living

Difficulties in the performance of activities of daily living (ADL) are a key feature of developmental coordination disorder (DCD). The DCDDaily-Q was developed to address children's motor performance in a comprehensive range ADL. The aim of this study was to investigate the psychometric properties of this parental questionnaire. Parents of 218 five to eight year-old children (DCD group: N=25; reference group: N=193) completed the research version of the new DCDDaily-Q and the Movement Assessment Battery for Children-2 (MABC2) Checklist and Developmental Coordination Disorder Questionnaire (DCDQ). Children were assessed with the MABC2 and DCDDaily. Item reduction analyses were performed and reliability (internal consistency and factor structure) and concurrent, discriminant, and incremental validity of the DCDDaily-Q were investigated. The final version of the DCDDaily-Q comprises 23 items that cover three underlying factors and shows good internal consistency (Cronbach's α>.80). Moderate correlations were found between the DCDDaily-Q and the other instruments used (p<.001 for the reference group; p>.05 for the DCD group). Discriminant validity of the DCDDaily-Q was good for DCDDaily-Q total scores (p<.001) and all 23 item scores (p<.01), indicating poorer performance in the DCD group. Sensitivity (88%) and specificity (92%) were good. The DCDDaily-Q better predicted DCD than currently used questionnaires (R(2)=.88). In conclusion, the DCDDaily-Q is a valid and reliable questionnaire to address children's ADL performance.

Running with a minimalist shoe increases plantar pressure in the forefoot region of healthy female runners

OBJECTIVES

Minimalist running shoes have been proposed as an alternative to barefoot running. However, several studies have reported cases of forefoot stress fractures after switching from standard to minimalist shoes. Therefore, the aim of the current study was to investigate the differences in plantar pressure in the forefoot region between running with a minimalist shoe and running with a standard shoe in healthy female runners during overground running.

DESIGN

Randomized crossover design.

METHODS

In-shoe plantar pressure measurements were recorded from eighteen healthy female runners. Peak pressure, maximum mean pressure, pressure time integral and instant of peak pressure were assessed for seven foot areas. Force time integral, stride time, stance time, swing time, shoe comfort and landing type were assessed for both shoe types. A linear mixed model was used to analyze the data.

RESULTS

Peak pressure and maximum mean pressure were higher in the medial forefoot (respectively 13.5% and 7.46%), central forefoot (respectively 37.5% and 29.2%) and lateral forefoot (respectively 37.9% and 20.4%) for the minimalist shoe condition. Stance time was reduced with 3.81%. No relevant differences in shoe comfort or landing strategy were found.

CONCLUSIONS

Running with a minimalist shoe increased plantar pressure without a change in landing pattern. This increased pressure in the forefoot region might play a role in the occurrence of metatarsal stress fractures in runners who switched to minimalist shoes and warrants a cautious approach to transitioning to minimalist shoe use.

Effect of rocker shoes on plantar pressure pattern in healthy female runners

Rocker profile shoes (rocker shoes) are one of the treatment options of metatarsalgia and forefoot stress fractures. The efficacy of rocker shoes in unloading the forefoot pressure has been shown in walking. In running, however, the effect of rocker shoes on forefoot pressure is unknown. Eighteen healthy female runners participated in this study. In-shoe plantar pressures were recorded during running with the standard running shoes and rocker shoes. Shoe comfort was assessed after each shoe measurement. Peak pressure (PP), maximum mean pressure (MMP) and force-time integral (FTI) were determined for seven foot areas. The effects of shoes on the different outcome variables were statistically analyzed using a linear mixed model. Running with the rocker shoes caused a significant reduction (p<0.001) in all pressure parameters in the central and lateral forefoot. FTI and MMP were also reduced by 11% and 12% in the medial forefoot while running with rocker shoes. Running with rocker shoes resulted in a significant increase in all pressure parameters at the heel region (p<0.001). Running with rocker shoes received a significant (p<0.01) lower comfort rate than running with standard running shoes. Rocker shoes might be beneficial for runners who are recovering from metatarsalgia or stress fractures of the forefoot region, as it reduces plantar pressure in the forefoot region.

Combined arm stretch positioning and neuromuscular electrical stimulation during rehabilitation does not improve range of motion, shoulder pain or function in patients after stroke: a randomised trial

QUESTION

Does static stretch positioning combined with simultaneous neuromuscular electrical stimulation (NMES) in the subacute phase after stroke have beneficial effects on basic arm body functions and activities?

DESIGN

Multicentre randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis.

PARTICIPANTS

Forty-six people in the subacute phase after stroke with severe arm motor deficits (initial Fugl-Meyer Assessment arm score ≤ 18).

INTERVENTION

In addition to conventional stroke rehabilitation, participants in the experimental group received arm stretch positioning combined with motor amplitude NMES for two 45-minute sessions a day, five days a week, for eight weeks. Control participants received sham arm positioning (ie, no stretch) and sham NMES (ie, transcutaneous electrical nerve stimulation with no motor effect) to the forearm only, at a similar frequency and duration.

OUTCOME MEASURES

The primary outcome measures were passive range of arm motion and the presence of pain in the hemiplegic shoulder. Secondary outcome measures were severity of shoulder pain, restrictions in performance of activities of daily living, hypertonia, spasticity, motor control and shoulder subluxation. Outcomes were assessed at baseline, mid-treatment, at the end of the treatment period (8 weeks) and at follow-up (20 weeks).

RESULTS

Multilevel regression analysis showed no significant group effects nor significant time × group interactions on any of the passive range of arm motions. The relative risk of shoulder pain in the experimental group was non-significant at 1.44 (95% CI 0.80 to 2.62).

CONCLUSION

In people with poor arm motor control in the subacute phase after stroke, static stretch positioning combined with simultaneous NMES has no statistically significant effects on range of motion, shoulder pain, basic arm function, or activities of daily living.

TRIAL REGISTRATION

NTR1748.

Exergaming for balance training of elderly: state of the art and future developments

Fall injuries are responsible for physical dysfunction, significant disability, and loss of independence among elderly. Poor postural control is one of the major risk factors for falling but can be trained in fall prevention programs. These however suffer from low therapy adherence, particularly if prevention is the goal. To provide a fun and motivating training environment for elderly, exercise games, or exergames, have been studied as balance training tools in the past years. The present paper reviews the effects of exergame training programs on postural control of elderly reported so far. Additionally we aim to provide an in-depth discussion of technologies and outcome measures utilized in exergame studies. Thirteen papers were included in the analysis. Most of the reviewed studies reported positive results with respect to improvements in balance ability after a training period, yet few reached significant levels. Outcome measures for quantification of postural control are under continuous dispute and no gold standard is present. Clinical measures used in the studies reviewed are well validated yet only give a global indication of balance ability. Instrumented measures were unable to detect small changes in balance ability as they are mainly based on calculating summary statistics, thereby ignoring the time-varying structure of the signals. Both methods only allow for measuring balance after the exergame intervention program. Current developments in sensor technology allow for accurate registration of movements and rapid analysis of signals. We propose to quantify the time-varying structure of postural control during gameplay using low-cost sensor systems. Continuous monitoring of balance ability leaves the user unaware of the measurements and allows for generating user-specific exergame training programs and feedback, both during one game and in timeframes of weeks or months. This approach is unique and unlocks the as of yet untapped potential of exergames as balance training tools for community dwelling elderly.

Biomechanics of slow running and walking with a rocker shoe

Evidence suggests a link between the loading of the Achilles tendon and the magnitude of the ankle internal plantar flexion moment during late stance of gait, which is clinically relevant in the management of Achilles tendinopathy. Some studies showed that rocker shoes can reduce the ankle internal plantar flexion moment. However, the existing evidence is not conclusive and focused on walking and scarce in running. Sixteen healthy runners participated in this study. Lower extremity kinetics, kinematics and electromyographic (EMG) signals of triceps surae and tibialis anterior were quantified for two types of shoes during running and walking. The peak ankle plantar flexion moment was reduced significantly in late stance of running (0.27 Nm/kg; p<0.001) and walking (0.24 Nm/kg; p<0.001) with the rocker shoe compared to standard shoe. The ankle power generation and plantar flexion moment impulse were also reduced significantly when running and walking with the rocker shoe (p<0.001). No significant changes in the knee and hip moments were found in running and walking. A significant delay of the EMG peak, approximately 2% (p<0.001), was present in the triceps surae when walking with rocker shoes. There were no significant changes in the EMG peak amplitude of triceps surae in running and walking. The peak amplitude of tibialis anterior was significantly increased (64.7 μV, p<0.001) when walking with rocker shoes. The findings show that rocker shoes reduce the ankle plantar flexion moment during the late stance phase of running and walking in healthy people.

Lower limb amputation in Northern Netherlands: unchanged incidence from 1991-1992 to 2003-2004

BACKGROUND

Investigating population changes gives insight into effectiveness and need for prevention and rehabilitation services. Incidence rates of amputation are highly varied, making it difficult to meaningfully compare rates between studies and regions or to compare changes over time.

STUDY DESIGN

Historical cohort study of transtibial amputation, knee disarticulation, and transfemoral amputations resulting from vascular disease or infection, with/without diabetes, in 2003-2004, in the three Northern provinces of the Netherlands.

OBJECTIVES

To report the incidence of first transtibial amputation, knee disarticulation, or transfemoral amputation in 2003-2004 and the characteristics of this population, and to compare these outcomes to an earlier reported cohort from 1991 to 1992.

METHODS

Population-based incidence rates were calculated per 100,000 person-years and compared across the two cohorts.

RESULTS

Incidence of amputation was 8.8 (all age groups) and 23.6 (≥45 years) per 100,000 person-years. This was unchanged from the earlier study of 1991-1992. The relative risk of amputation was 12 times greater for people with diabetes than for people without diabetes.

CONCLUSIONS

Investigation is needed into reasons for the unchanged incidence with respect to the provision of services from a range of disciplines, including vascular surgery, diabetes care, and multidisciplinary foot clinics.

CLINICAL RELEVANCE

This study shows an unchanged incidence of amputation over time and a high risk of amputation related to diabetes. Given the increased prevalence of diabetes and population aging, both of which present an increase in the population at risk of amputation, finding methods for reducing the rate of amputation is of importance.

Reconsidering evidence-based practice in prosthetic rehabilitation: a shared enterprise

BACKGROUND

A divide is experienced between producers and users of evidence in prosthetic rehabilitation.

OBJECTIVE

To discuss the complexity inherent in establishing evidence-based practice in a prosthetic rehabilitation team illustrated by the case of prosthetic prescription for elderly dysvascular transfemoral amputee patients.

STUDY DESIGN

A qualitative research design was used, in which data from multiple sources was triangulated to extract themes for discussion.

METHODS

This discussion paper draws on empirical material gathered by individual and focus-group interviews with members of a prosthetic rehabilitation team, information on technological advancements presented on websites of orthopaedic industry, guidelines and literature study.

RESULTS

A prosthetic rehabilitation team needs to deal with lack of evidence, contradictory results, various classification systems, diverging interests of different stakeholders and many modifying factors, and all of this in a continuous technological changing environment. Integrating research designs with different strengths but not sharing the same biases may help researchers to deal with the multimorbidity and multifaceted disability of the target group. Articulating clinical knowledge, patients' needs and values in a systematic way provides depth, detail, nuance and context for evidence-based practice issues in prosthetic rehabilitation.

CONCLUSIONS

Reconsidering the relationship between evidence, technology and rehabilitation practice is an imperative shared enterprise for clinicians and researchers. Scientific, clinical and patient-related knowledge are seen as important knowledge practices that should inform and strengthen each other.

CLINICAL RELEVANCE

This discussion paper puts the academic clinical debate on evidence-based practice in prosthetics and orthotics in another light. By demonstrating the complexities surrounding evidence-based practice, it is argued and illustrated how both researchers and clinicians can contribute to optimal patient care in which evidence, technology and rehabilitation practice are integrated.

Rocker shoe, minimalist shoe, and standard running shoe: a comparison of running economy

OBJECTIVES

Running with rocker shoes is believed to prevent lower limb injuries. However, it is not clear how running in these shoes affects the energy expenditure. The purpose of this study was, therefore, to assess the effects of rocker shoes on running economy in comparison with standard and minimalist running shoes.

DESIGN

Cross-over design.

METHODS

Eighteen endurance female runners (age=23.6 ± 3 years), who were inexperienced in running with rocker shoes and with minimalist/barefoot running, participated in this study. Oxygen consumption, carbon dioxide production, heart rate and rate of perceived exertion were measured while participants completed a 6-min sub-maximal treadmill running test for each footwear condition. The data of the last 2 min of each shoe condition were averaged for analysis. A linear mixed model was used to compare differences among three footwear conditions.

RESULTS

Oxygen consumption during running with rocker shoes was on average 4.5% higher than with the standard shoes (p<0.001) and 5.6% higher than with the minimalist shoe (p<0.001). No significant differences were found in heart rate and rate of perceived exertion across three shoe conditions.

CONCLUSIONS

Female runners, who are not experienced in running with the rocker shoes and minimalist shoes, show more energy expenditure during running with the rocker shoes compared with the standard and minimalist shoes. As the studied shoes were of different masses, part of the effect of increased energy expenditure with the rocker shoe is likely to be due to its larger mass as compared with standard running shoes and minimalist shoes.

Development and psychometric properties of the DCDDaily: a new test for clinical assessment of capacity in activities of daily living in children with developmental coordination disorder

Objective:

To develop the DCDDaily, an instrument for objective and standardized clinical assessment of capacity in activities of daily living (ADL) in children with developmental coordination disorder (DCD), and to investigate its usability, reliability, and validity.

Subjects:

Five to eight-year-old children with and without DCD.

Main measures:

The DCDDaily was developed based on thorough review of the literature and extensive expert involvement. To investigate the usability (assessment time and feasibility), reliability (internal consistency and repeatability), and validity (concurrent and discriminant validity) of the DCDDaily, children were assessed with the DCDDaily and the Movement Assessment Battery for Children-2 Test, and their parents filled in the Movement Assessment Battery for Children-2 Checklist and Developmental Coordination Disorder Questionnaire.

Results:

459 children were assessed (DCD group, n = 55; normative reference group, n = 404). Assessment was possible within 30 minutes and in any clinical setting. For internal consistency, Cronbach’s α = 0.83. Intraclass correlation = 0.87 for test–retest reliability and 0.89 for inter-rater reliability. Concurrent correlations with Movement Assessment Battery for Children-2 Test and questionnaires were ρ = −0.494, 0.239, and −0.284, p < 0.001. Discriminant validity measures showed significantly worse performance in the DCD group than in the control group (mean (SD) score 33 (5.6) versus 26 (4.3), p < 0.001). The area under curve characteristic = 0.872, sensitivity and specificity were 80%.

Conclusions:

The DCDDaily is a valid and reliable instrument for clinical assessment of capacity in ADL, that is feasible for use in clinical practice.

Active LifestyLe Rehabilitation interventions in aging spinal cord injury (ALLRISC): a multicentre research program

BACKGROUND

With today's specialized medical care, life expectancy of persons with a spinal cord injury (SCI) has considerably improved. With increasing age and time since injury, many individuals with SCI, however, show a serious inactive lifestyle, associated with deconditioning and secondary health conditions (SHCs) (e.g. pressure sores, urinary and respiratory tract infections, osteoporosis, upper-extremity pain, obesity, diabetes, cardiovascular disease) and resulting in reduced participation and quality of life (QoL). Avoiding this downward spiral, is crucial.

OBJECTIVES

To understand possible deconditioning and SHCs in persons aging with a SCI in the context of active lifestyle, fitness, participation and QoL and to examine interventions that enhance active lifestyle, fitness, participation and QoL and help prevent some of the SHCs.

METHODS

A multicentre multidisciplinary research program (Active LifestyLe Rehabilitation Interventions in aging Spinal Cord injury, ALLRISC) in the setting of the long-standing Dutch SCI-rehabilitation clinical research network.

RESULTS

ALLRISC is a four-study research program addressing inactive lifestyle, deconditioning, and SHCs and their associations in people aging with SCI. The program consists of a cross-sectional study (n = 300) and three randomized clinical trials. All studies share a focus on fitness, active lifestyle, SHCs and deconditioning and outcome measures on these and other (participation, QoL) domains. It is hypothesized that a self-management program, low-intensity wheelchair exercise and hybrid functional electrical stimulation-supported leg and handcycling are effective interventions to enhance active life style and fitness, help to prevent some of the important SHCs in chronic SCI and improve participation and QoL.

CONCLUSION

ALLRISC aims to provide evidence-based preventive components of a rehabilitation aftercare system that preserves functioning in aging persons with SCI.

Epidemiology of ankle and foot overuse injuries in sports: A systematic review

Studies regarding ankle and foot overuse injuries are quite diverse in research methodology, data reporting, and outcomes. The aims of this systematic review were to analyze the methodology of published studies regarding ankle and foot overuse injuries in different sports disciplines and to summarize epidemiological data of ankle and foot overuse injuries. Four electronic databases, PubMed (MEDLINE), EMBASE, CINAHL, and SPORTDiscus(®) were systematically searched up to June 2011. A total of 89 articles on 23 sports disciplines were included in this review. Soccer, running, and gymnastics were the most frequently studied sports. Achilles tendinopathy, plantar fasciitis, and stress fracture were the most frequently studied injuries. Study design and reporting methods were heterogeneous. Most studies suffered from a weak methodology and poor reporting. The most common weaknesses were lack of a clear case definition, describing assessment procedures and reporting sample characteristics. Due to methodological heterogeneity of studies, inter-sports and intra-sports comparisons and meta-analysis were not possible. Methodology of most studies on incidence and prevalence of ankle and foot overuse injuries is insufficient. Based on the results, we recommend authors to clearly define cases, describe assessment procedures and report sample characteristics adequately.

What influences a patient's decision to use custom-made orthopaedic shoes?

BACKGROUND

Despite potential benefits, some patients decide not to use their custom-made orthopaedic shoes (OS). Factors are known in the domains 'usability', 'communication and service', and 'opinion of others' that influence a patient's decision to use OS. However, the interplay between these factors has never been investigated. The aim of this study was to explore the interplay between factors concerning OS, and the influences thereof on a patient's decision to use OS.

METHODS

A mixed-methods design was used, combining qualitative and quantitative data by means of sequential data analysis and triangulation. Priority was given to the qualitative part. Qualitative data was gathered with a semi-structured interview covering the three domains. Data was analysed using the framework approach. Quantitative data concerned the interplay between factors and determining a rank-order for the importance of factors of 'usability'.

RESULTS

A patient's decision to use OS was influenced by various factors indicated as being important and by acceptance of their OS. Factors of 'usability' were more important than factors of 'communication'; the 'opinion of others' was of limited importance. An improvement of walking was indicated as the most important factor of 'usability'. The importance of other factors (cosmetic appearance and ease of use) was determined by reaching a compromise between these factors and an improvement of walking.

CONCLUSIONS

A patient's decision to use OS is influenced by various factors indicated as being important and by acceptance of their OS. An improvement of walking is the most important factor of 'usability', the importance of other factors (cosmetic appearance and ease of use) is determined by reaching compromises between these factors and an improvement of walking. Communication is essential to gain insight in a patient's acceptance and in the compromises they are willing to reach. This makes communication the key for clinicians to influence a patient's decision to use OS.

Determining asymmetry of roll-over shapes in prosthetic walking

How does the inherent asymmetry of the locomotor system in people with lower-limb amputation affect the ankle-foot roll-over shape of prosthetic walking? In a single-case design, we evaluated the walking patterns of six people with lower-limb amputation (3 transtibial and 3 transfemoral) and three matched nondisabled controls. We analyzed the walking patterns in terms of roll-over characteristics and spatial and temporal factors. We determined the level of asymmetry by roll-over shape comparison (root-mean-square distance) as well as differences in radius of curvature. In addition, we calculated ratios to determine spatial and temporal asymmetries and described different aspects of asymmetry of roll-over shapes. All participants showed some level of asymmetry in roll-over shape, even the nondisabled controls. Furthermore, we found good intralimb reproducibility for the group as a whole. With respect to spatial and temporal factors, the participants with transtibial amputation had a quite symmetrical gait pattern, while the gait in the participants with transfemoral amputation was more asymmetrical. The individual ankle-foot roll-over shapes provide additional insight into the marked individual adjustments occurring during the stance phase of the nondisabled limb. The two methods we present are suitable for determining asymmetry of roll-over shapes; both methods should be used complementarily.

Principles of obstacle avoidance with a transfemoral prosthetic limb

In this study, conditions that enable a prosthetic knee flexion strategy in transfemoral amputee subjects during obstacle avoidance were investigated. This study explored the hip torque principle and the static ground principle as object avoidance strategies. A prosthetic limb simulator device was used to study the influence of applied hip torques and static ground friction on the prosthetic foot trajectory. Inverse dynamics were used to calculate the energy produced by the hip joint. A two-dimensional forward dynamics model was used to investigate the relation between obstacle-foot distance and the necessary hip torques utilized during obstacle avoidance. The study showed that a prosthetic knee flexion strategy was facilitated by the use of ground friction and by larger active hip torques. This strategy required more energy produced by the hip compared to a knee extension strategy. We conclude that when an amputee maintains enough distance between the distal tip of the foot and the obstacle during stance, he or she produces sufficiently high, yet feasible, hip torques and uses static ground friction, the amputee satisfies the conditions for enable stepping over an obstacle using a knee flexion strategy.

Stabilizing moments of force on a prosthetic knee during stance in the first steps after gait initiation

In this study, the occurrences of stabilizing and destabilizing external moments of force on a prosthetic knee during stance, in the first steps after gait initiation, in inexperienced users were investigated. Primary aim was to identify the differences in the external moments during gait initiation with the sound leg leading and the prosthetic leg leading. A prosthetic leg simulator device, with a flexible knee, was used to test able-bodied subject, with no walking aid experience. Inverse dynamics calculations were preformed to calculate the external moments. The subjects learned to control the prosthetic leg within 100 steps, without walking aids, evoking similar patterns of external moments of force during the steps after the gait initiation, either with their sound leg loading or prosthetic leg leading. Critical phases in which a sudden flexion of the knee can occur were found just after heelstrike and just before toe off, in which the external moment of force was close to the internal moment produced by a knee extension aiding spring in the opposite direction.

Proprioceptive deficits after ACL injury: are they clinically relevant?

OBJECTIVE

To establish the clinical relevance of proprioceptive deficits reported after anterior cruciate ligament (ACL) injury.

MATERIAL AND METHODS

A literature search was done in electronic databases from January 1990 to June 2009. Inclusion criteria for studies were ACL deficient (ACL-D) and ACL reconstruction (ACL-R) articles written in English, Dutch or German and calculation of correlation(s) between proprioception tests and clinical outcome measures. Clinical outcome measures were muscle strength, laxity, hop test, balance, patient-reported outcome, objective knee score rating, patient satisfaction or return to sports. Studies included in the review were assessed on their methodological quality.

RESULTS

In total 1161 studies were identified of which 24 met the inclusion criteria. Pooling of all data was not possible due to substantial differences in measurement techniques and data analysis. Most studies failed to perform reliability measurements of the test device used. In general, the correlation between proprioception and laxity, balance, hop tests and patient outcome was low. Four studies reported a moderate correlation between proprioception, strength, balance or hop test.

CONCLUSION

There is limited evidence that proprioceptive deficits as detected by commonly used tests adversely affect function in ACL-D and ACL-R patients. Development of new tests to determine the relevant role of the sensorimotor system is needed. These tests should ideally be used as screening tests for primary and secondary prevention of ACL injury.