Physical strain of walking in people with neuromuscular diseases is high and relates to step activity in daily life.

OBJECTIVE: To determine the physical strain of walking and assess its relationship with daily steps and intensity of daily activity in people with neuromuscular diseases. DESIGN: Cross-sectional study. SUBJECTS/PATIENTS: Sixty-one adults with neuromuscular diseases. METHODS: Physical strain of walking, defined as oxygen consumption during comfortable walking relative to peak oxygen uptake. Daily step count and daily time spent in moderate and vigorous physical activity were assessed using accelerometry and heart rate measurements, respectively. Regression analyses assessed the relationships between log daily step count and log daily time spent in moderate and vigorous physical activity, and physical strain of walking. RESULTS: The mean (standard deviation) physical strain of walking was 73 (20)% Log daily step count and physical strain were negatively associated (ß = -0.47). No association was found with log daily time spent in moderate and vigorous physical activity. CONCLUSIONS: The highly increased physical strain of comfortable walking indicates that walking is very demanding for people with neuromuscular diseases and is associated with a reduction in daily step activity. The absence of a relationship between intensity of activities and physical strain indicates that, despite a reduction in daily step activity, strenuous daily activities may still be performed.

Minimization of metabolic cost of transport predicts changes in gait mechanics over a range of ankle-foot orthosis stiffnesses in individuals with bilateral plantar flexor weakness.

Neuromuscular disorders often lead to ankle plantar flexor muscle weakness, which impairs ankle push-off power and forward propulsion during gait. To improve walking speed and reduce metabolic cost of transport (mCoT), patients with plantar flexor weakness are provided dorsal-leaf spring ankle-foot orthoses (AFOs). It is widely believed that mCoT during gait depends on the AFO stiffness and an optimal AFO stiffness that minimizes mCoT exists. The biomechanics behind why and how an optimal stiffness exists and benefits individuals with plantar flexor weakness are not well understood. We hypothesized that the AFO would reduce the required support moment and, hence, metabolic cost contributions of the ankle plantar flexor and knee extensor muscles during stance, and reduce hip flexor metabolic cost to initiate swing. To test these hypotheses, we generated neuromusculoskeletal simulations to represent gait of an individual with bilateral plantar flexor weakness wearing an AFO with varying stiffness. Predictions were based on the objective of minimizing mCoT, loading rates at impact and head accelerations at each stiffness level, and the motor patterns were determined via dynamic optimization. The predictive gait simulation results were compared to experimental data from subjects with bilateral plantar flexor weakness walking with varying AFO stiffness. Our simulations demonstrated that reductions in mCoT with increasing stiffness were attributed to reductions in quadriceps metabolic cost during midstance. Increases in mCoT above optimum stiffness were attributed to the increasing metabolic cost of both hip flexor and hamstrings muscles. The insights gained from our predictive gait simulations could inform clinicians on the prescription of personalized AFOs. With further model individualization, simulations based on mCoT minimization may sufficiently predict adaptations to an AFO in individuals with plantar flexor weakness.

Preliminary effectiveness and production time and costs of three-dimensional printed orthoses in chronic hand conditions: an interventional feasibility study.

OBJECTIVE: To assess the preliminary effectiveness of three-dimensional printed orthoses compared with conventionally custom-fabricated orthoses in persons with chronic hand conditions on performance of daily activities, hand function, quality of life, satisfaction, and production time and costs. DESIGN: Interventional feasibility study. SUBJECTS: Chronic hand orthotic users (n = 21). METHODS: Participants received a new three-dimensional printed orthosis according to the same type as their current orthosis, which served as the control condition. Primary outcome was performance of daily activities (Patient-Reported Outcomes Measurement Information System-Upper Extremity; Michigan Hand Questionnaire). Secondary outcomes were hand function, quality of life, and satisfaction. Furthermore, production time and costs were recorded. RESULTS: At 4 months' follow-up, no significant differences were found between three-dimensional printed orthoses and participants' existing conventional orthoses on activity performance, hand function, and quality of life. Satisfaction with the three-dimensional printed orthosis was significantly higher and the production time and costs for three-dimensional printed orthoses were significantly lower compared with conventional orthoses. The three-dimensional printed orthosis was preferred by 79% of the participants. CONCLUSIONS: This feasibility study in chronic hand conditions suggests that three-dimensional printed orthoses are similar to conventional orthoses in terms of activity performance, hand function, and quality of life. Satisfaction, and production time and costs favoured the three-dimensional printed hand orthoses.

Two-year course of walking adaptability in persons living with late effects of polio.

OBJECTIVE: To evaluate the 2-year course of walking adaptability in persons with late effects of polio. DESIGN: Prospective cohort study. PATIENTS: A total of 48 persons with late effects of polio (69% female, mean age 63.1 years) with a fall history and/or fear of falling. METHODS: Walking adaptability (i.e. variable target-stepping and reactive obstacle-avoidance) was assessed on an interactive treadmill at baseline, 1 year and 2 years. Further, leg-muscle strength and balance were assessed at baseline. The course of walking adaptability was analysed with linear mixed models. Based on median values, subgroups were defined for low vs high baseline walking-adaptability and for clinical characteristics. Tme by subgroup interactions were analysed. RESULTS: Variable target-stepping and reactive obstacle-avoidance did not change (p > 0.285). Reactive obstacle-avoidance improved for persons with a high balance score at baseline (p = 0.037), but not for those with lower scores (p = 0.531). No other time by subgroup interactions were found (p > 0.126). CONCLUSION: Walking adaptability did not change in persons with late effects of polio over 2 years, and walking adaptability course did not differ between subgroups stratified for walking adaptability determinants, except for balance. Since falls are a major problem among persons with late effects of polio, future studies should investigate whether walking adaptability declines over a longer time and which persons are most at risk.

Safety, walking ability, and satisfaction outcomes of the NEURO TRONIC stance-control knee-ankle-foot orthosis (SCKAFO): A comparative evaluation to the E-MAG active SCKAFO.

BACKGROUND: Stance control knee-ankle-foot orthoses (SCKAFOs) ensure knee stability by locking during stance while allowing knee flexion during swing. Differences in function of the knee joints and building principles between devices may affect their effectiveness. OBJECTIVE: To investigate the preliminary effectiveness of a NEURO TRONIC on safety outcomes, net energy cost (EC), and user experiences in individuals already using an E-MAG Active SCKAFO. STUDY DESIGN: Prospective uncontrolled intervention study. METHODS: A convenience sample of 10 subjects with flaccid lower extremity muscle weakness, including the quadriceps, due to neuromuscular disorders already using an E-MAG Active SCKAFO were provided with a newly fabricated NEURO TRONIC SCKAFO. Outcomes included knee joint locking failures and unlocking failures (ULFs) (i.e., percentage of steps the knee joint failed to lock/unlock) when walking under challenging conditions on an instrumented treadmill while wearing a safety harness; net EC (J/kg per meter) assessed with a 6-min walk test at comfortable speed; 3D gait kinematics and kinetics; and patient-reported outcomes. RESULTS: No differences between devices were found for knee joint locking failures (both devices 0%) and ULFs (9.9% for the NEURO TRONIC vs. 13.9% for the E-MAG Active SCKAFO). The mean (standard deviation) net EC with the NEURO TRONIC SCKAFO was 8.2% (from 3.68 [0.81] to 3.38 [0.75] J/kg per meter, p = 0.123) lower, although not significantly, compared with that with the E-MAG Active SCKAFO. Significant improvements with the NEURO TRONIC SCKAFO were found for ankle power ( p = 0.003), perceived walking effort ( p = 0.014), and reported falls ( p = 0.034). CONCLUSION: Both the NEURO TRONIC SCKAFO and the E-MAG Active SCKAFO were safe in terms of knee joint locking, while ULFs were frequent with both devices. The net EC with the NEURO TRONIC SCKAFO decreased, although not significantly, by 8.2%, likely due to insufficient power. Perceived walking effort was in favor of the NEURO TRONIC SCKAFO.

Gait stability and the relationship with energy cost of walking in polio survivors with unilateral plantarflexor weakness.

BACKGROUND: Polio survivors often exhibit plantarflexor weakness, which impairs gait stability, and increases energy cost of walking. Quantifying gait stability could provide insights in the control mechanisms polio survivors use to maintain gait stability and in whether impaired gait stability is related to the increased energy cost of walking. RESEARCH QUESTION: Is gait stability impaired in polio survivors with plantarflexor weakness compared to able-bodied individuals, and does gait stability relate to energy cost of walking? METHODS: We retrospectively analyzed barefoot biomechanical gait data of 31 polio survivors with unilateral plantarflexor weakness and of 24 able-bodied individuals. We estimated gait stability by calculating variability (SD) of step width, step length, double support time, and stance time, and by the mean and variability (SD) of the mediolateral and anteroposterior margin of stability (MoSML and MoSAP). In addition, energy cost of walking (polio survivors only) at comfortable speed was analyzed. RESULTS: Comfortable speed was 31% lower in polio survivors compared to able-bodied individuals (p < 0.001). Corrected for speed differences, step width variability was significantly larger in polio survivors (+41%), double support time variability was significantly smaller (-27%), MoSML (affected leg) was significantly larger (+80%), and MoSAP was significantly smaller (affected leg:-17% and non-affected leg:-15%). Step width and step length variability (affected leg) were positively correlated with energy cost of walking (r = 0.502 and r = 0.552). MoSAP (non-affected leg) was negatively correlated with energy cost of walking (r = -0.530). SIGNIFICANCE: Polio survivors with unilateral plantarflexor weakness demonstrated an impaired gait stability. Increased step width and step length variability and lower MoSAP could be factors related to the elevated energy cost of walking in polio survivors. These findings increase our understanding of stability problems due to plantarflexor weakness, which could be used for the improvement of (orthotic) interventions to enhance gait stability and reduce energy cost in polio survivors.

Validity and reliability of the Dutch translation of the OPUS' client satisfaction with device module in chronic users of hand orthoses.

BACKGROUND: Orthosis satisfaction is an important outcome in assessing quality of care. However, no measurement specifically assessing orthosis satisfaction is available in the Dutch language. Therefore, the aim of this study was to translate the Client Satisfaction with Device (CSD) module of the Orthotics and Prosthetics Users' Survey (OPUS) into Dutch, and to assess its content validity, structural validity and reliability in persons with chronic hand conditions. METHODS: The CSD was translated and cross-cultural adapted according to respective guidelines. To determine content validity, 10 chronic hand orthotic users and two professionals judged the relevance, comprehensibility, and comprehensiveness of the Dutch CSD (D-CSD). Thereafter, in a cross-sectional study, 76 persons were asked to complete the D-CSD twice, with a 2-week interval. Dimensionality of the D-CSD was examined by principal component analysis (PCA), and factor model fit was assessed by confirmatory factor analysis (CFA). Reliability was assessed as internal consistency and test-retest reliability, including the 95% limits of agreement (LoA), the standard error of measurement (SEM) and smallest detectable change (SDC). RESULTS: The D-CSD items and response options were deemed relevant and comprehensible. After adding an item on cleaning the orthosis, content validity was judged sufficient. PCA indicated a one-factor model, which was confirmed by CFA. We found good internal consistency (Cronbach's alpha = 0.82; 95%CI 0.75-0.87), and moderate to good test-retest reliability (ICC = 0.81; 95%CI 0.71-0.87). There was no difference between the mean D-CSD score at test (26.8 points) and retest (25.9 points) (mean (SD) difference: 0.86 points (4.00); 95%CI -0.06-1.79; p = 0.07). The 95% LoA were -6.99 to 8.71, and the SEM and SDC were 2.88 and 7.98 points, respectively. CONCLUSIONS: Based on sufficient content and structural validity, and good reliability, we consider the D-CSD a useful tool to evaluate orthosis satisfaction in persons with chronic hand conditions on group level. Because of a relatively high SDC, sensitivity to detect changes over time on individual level is limited. STUDY REGISTRATION NUMBER: NCT05320211.

Fatigue-related gait adaptations in children with cerebral palsy.

AIM: To obtain insights into the effects of fatigue on the kinematics, kinetics, and energy cost of walking (ECoW) in children with cerebral palsy (CP). METHOD: In this prospective observational study, 12 children with CP (mean age 12 years 9 months, SD 2 years 7 months; four females, eight males) and 15 typically developing children (mean age 10 years 8 months, SD 2 years 4 months; seven females, eight males) followed a prolonged intensity-based walking protocol on an instrumented treadmill, combined with gas analysis measurements. The protocol consisted of consecutive stages, including a 6-minute walking exercise (6MW) at comfortable speed, 2 minutes of moderate-intensity walking (MIW) (with a heart rate > 70% of its predicted maximal), and 4 minutes walking after MIW. If necessary, the speed and slope were incremented to reach MIW. Outcomes were evaluated at the beginning and end of the 6MW and after MIW. RESULTS: With prolonged walking, Gait Profile Scores deteriorated slightly for both groups (p < 0.01). Knee flexion increased during early stance (p = 0.004) and ankle dorsiflexion increased during late stance (p = 0.034) in children with CP only. Negligible effects were found for kinetics. No demonstrable change in ECoW was found in either group (p = 0.195). INTERPRETATION: Kinematic deviations in children with CP are progressive with prolonged walking. The large variation in adaptations indicates that an individual approach is recommended to investigate the effects of physical fatigue on gait in clinical practice.

Preliminary effectiveness of 3D-printed orthoses in chronic hand conditions: study protocol for a non-randomised interventional feasibility study.

INTRODUCTION: Hand orthoses are often provided to improve performance of activities of daily life (ADL). Yet, the manufacturing process of conventional custom-fabricated hand orthoses is a time-consuming and labour-intensive process. Even though three-dimensional (3D) printing of orthoses is a rapidly growing area that can facilitate the manufacturing process of hand orthoses, evidence on the effectiveness, costs and production time of 3D-printed orthoses in chronic hand conditions is scarce. This study aims to assess (1) the preliminary effectiveness of 3D-printed orthoses compared with conventionally custom-fabricated orthoses in persons with chronic hand conditions, (2) production time and costs of both orthoses and (3) experiences of the participants and orthotists with the manufacturing process of the 3D-printed orthosis. METHODS AND ANALYSIS: In this prospective non-randomised interventional feasibility study, 20 adults with various chronic hand conditions using a conventional thumb, wrist or wrist-thumb orthosis will be provided with a 3D-printed corresponding type of orthosis. Assessments will be done 2 weeks prior to the intervention and at baseline for the conventional orthosis, and at 1 month and 4 months follow-up for the 3D-printed orthosis. The primary outcome is change from baseline in ADL performance (custom short form Dutch-Flemish Patient-Reported Outcomes Measurement Information System-Upper Extremity; ADL domain Michigan Hand Outcomes Questionnaire Dutch language version (MHQ-DLV)) at 4 months follow-up. Secondary outcomes include general hand function (MHQ-DLV), satisfaction with the orthosis (Dutch Client Satisfaction with Device; Dutch version of the Quebec User Evaluation of Satisfaction with Assistive Technology), usability (in-house questionnaire) and quality of life (EuroQoL 5-Dimension 5-Level). Costs and production time of the conventional and 3D-printed orthoses will be prospectively recorded. Experiences regarding the manufacturing process will be obtained from participants and orthotists (in-house questionnaire). ETHICS AND DISSEMINATION: The Medical Ethics Committee of the Amsterdam UMC, Academic Medical Centre, has waived the requirement for ethical review of this study. Results will be disseminated through peer-reviewed journals, scientific conferences, and media aimed at a broad audience including patients. TRIAL REGISTRATION NUMBER: NCT05320211.

Effects of specialist care lower limb orthoses on personal goal attainment and walking ability in adults with neuromuscular disorders.

BACKGROUND: Lower limb orthoses intend to improve walking in adults with neuromuscular disorders (NMD). Yet, reported group effects of lower limb orthoses on treatment outcomes have generally been small and heterogeneous. We propose that guideline-based orthotic care within a multidisciplinary expert setting may improve treatment outcomes. AIM: To examine the effectiveness of specialist care orthoses compared to usual care orthoses on personal goal attainment and walking ability. DESIGN: Cohort study. POPULATION: Adults with NMD who experienced walking problems due to calf and/or quadriceps muscle weakness and were provided with a specialist care lower limb orthosis between October 2011 and January 2021. METHODS: Three months after provision, the specialist care orthosis was compared to the usual care orthosis worn at baseline in terms of personal goal attainment (Goal Attainment Scaling (GAS)), comfortable walking speed (m/s), net energy cost (J/kg/m) (both assessed during a 6-minute walk test), perceived walking ability and satisfaction. RESULTS: Sixty-four adults with NMD were eligible for analysis. The specialist care orthoses comprised 19 dorsiflexion-restricting ankle-foot orthoses (AFOs), 22 stance-control knee-ankle-foot orthoses (KAFOs) and 23 locked KAFOs. Overall, 61% of subjects showed a clinically relevant improvement in GAS score. Perceived safety, stability, intensity, fear of falling and satisfaction while walking all improved (p≤0.002), and subjects were satisfied with their specialist care orthosis and the services provided. Although no effects on walking speed or net energy cost were found in combined orthosis groups, specialist care AFOs significantly reduced net energy cost (by 9.5%) compared to usual care orthoses (from mean (SD) 3.81 (0.97) to 3.45 (0.80) J/kg/m, p = 0.004). CONCLUSION: Guideline-based orthotic care within a multidisciplinary expertise setting could improve treatment outcomes in adults with NMD compared to usual orthotic care by improvements in goal attainment and walking ability. A randomized controlled trial is now warranted to confirm these results.

Efficacy of aerobic exercise on aerobic capacity in slowly progressive neuromuscular diseases: A systematic review and meta-analysis.

BACKGROUND: Aerobic exercise aims to improve aerobic capacity. OBJECTIVE: To summarize the evidence on the efficacy of aerobic exercise on aerobic capacity in slowly progressive neuromuscular diseases (NMDs). METHODS: We searched the electronic databases MEDLINE, EMBASE, SPORTDiscus and Web of Science Conference Proceedings Index for articles published up to June 17, 2021, selecting randomized controlled trials that included adults with slowly progressive NMDs and compared aerobic exercise to no aerobic exercise. The primary outcome was peak oxygen uptake (VO2peak) directly post-intervention. Secondary outcomes included other peak test parameters, submaximal test parameters, long-term outcomes ≥8 weeks post-intervention, adherence and adverse events. Meta-analyses were performed for the primary outcome and for secondary outcomes when reported in more than 2 studies. Risk of bias was assessed with the Cochrane Risk of Bias tool and quality of evidence according to GRADE. RESULTS: Nine studies were included (195 participants with 8 different NMDs). Eight studies were rated at high risk of bias and 1 study was rated at some concerns. Duration of exercise programs ranged from 6 to 26 weeks, with 3 weekly training sessions of 20 to 40 min, based on maximal capacity. Meta-analyses revealed short-term moderate beneficial effects of aerobic exercise on VO2peak (standardized mean difference [SMD] 0.55, 95% CI 0.23; 0.86) and peak workload (SMD 0.61, 95% CI 0.24; 0.99). Long-term effects were not assessed. Most training sessions (83-97%) were completed, but time spent in target intensity zones was not reported. Included studies lacked detailed adverse event reporting. CONCLUSIONS: There is low-quality evidence that aerobic exercise is safe and leads to moderate improvement of aerobic capacity directly post-intervention in slowly progressive NMDs, but the long-term efficacy remains unclear. Detailed information about the time spent in target intensity zones and adverse events is lacking. PROSPERO: CRD42020200083.

Six Minutes Walking in Polio Survivors: Effects on Fatigue and Walking Adaptability.

OBJECTIVE: To investigate whether 6-min walking is fatiguing for polio survivors, and how fatigue influences their normal and adaptive walking. DESIGN: Cross-sectional study. PATIENTS: Polio survivors (n = 23) with ≥ 1 fall and/or fear of falling reported in the previous year and healthy individuals (n = 11). METHODS: Participants performed 1 normal-walk test and 2 walking-adaptability tests (target stepping and narrow-beam walking) on an instrumented treadmill at fixed self-selected speed, each test lasting 6 min. Leg-muscle fatigue (leg-muscle activation, measured with surface electromyography), cardiorespiratory fatigue (heart rate, rate of perceived exertion), gait and walking-adaptability performance were assessed. The study compared: (i) the first and last minute per test, (ii) normal and adaptive walking, and (iii) groups. RESULTS: Leg-muscle activation did not change during normal walking (p > 0.546), but declined over time during adaptive walking, especially in polio survivors (p < 0.030). Cardiorespiratory fatigue increased during all tests (p < 0.001), especially in polio survivors (p < 0.01), and was higher during adaptive than normal walking (p < 0.007). Target-stepping performance declined in both groups (p = 0.007), while narrow-beam walking improved in healthy individuals (p < 0.001) and declined in polio survivors (p < 0.001). CONCLUSION: Cardiorespiratory fatigue might further degrade walking adaptability, especially among polio survivors during narrow-beam walking. This might increase the risk of falls among polio survivors.

Factors Associated With Walking Adaptability and Its Relationship With Falling in Polio Survivors.

OBJECTIVE: To explore factors associated with walking adaptability and associations between walking adaptability and falling in polio survivors. DESIGN: Cross-sectional study. SETTING: Outpatient expert polio clinic. PARTICIPANTS: Polio survivors (N=46) who fell in the previous year and/or reported fear of falling. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Walking adaptability was assessed on an interactive treadmill and operationalized as variable target-stepping and reactive obstacle avoidance performance. Further, we collected walking speed and assessed leg muscle strength, balance performance (Berg Balance Scale and Timed-Up-and-Go Test), balance confidence (Activities-specific Balance Confidence scale), ambulation level, orthosis use, fear of falling, and number of falls in the previous year. RESULTS: With walking speed included as a covariate, muscle weakness of the most affected leg and balance confidence explained 54% of the variance in variable target-stepping performance. For reactive obstacle avoidance performance, muscle weakness of the most affected leg and knee extensor strength of the least affected leg explained 32% of the variance. Only target-stepping performance was significantly related to the number of falls reported in the previous year (R2=0.277, P<.001) and mediated the relation between leg muscle weakness and balance confidence with falling. CONCLUSION: Our exploratory study suggests that leg muscle weakness and reduced balance confidence limit walking adaptability in polio survivors. Because poorer target stepping rather than obstacle avoidance performance was associated with falling, our results indicate that a limited ability to ensure safe foot placement may be a fall risk factor in this group. These findings should be confirmed in a larger sample.

Validity and reproducibility of C-Mill walking-adaptability assessment in polio survivors.

BACKGROUND: The C-Mill interactive treadmill allows for a safe walking-adaptability assessment, unveiling reduced walking adaptability in polio survivors compared to healthy individuals, possibly related to their high fall rate. However, evidence on its validity and reproducibility is scarce. RESEARCH QUESTION: What is the validity and reproducibility of C-Mill walking-adaptability assessment in polio survivors? METHODS: Polio survivors with a history and/or fear of falling (n = 46) performed two walking-adaptability assessments, 1-2 weeks apart, including target-stepping tests (with 0%, 20% and 30% inter-target variance) and obstacle-avoidance tests (anticipatory and reactive). We examined (1) face validity by determining Group effects (for subgroups stratified for fall frequency, fear of falling and leg muscle weakness) and Condition effects (for difficulty level) on walking-adaptability outcomes, (2) construct validity by correlating walking-adaptability and balance outcomes, and (3) content validity by establishing possible ceiling effects. We determined whether face-validity findings were reproducible over test occasions and calculated Intraclass Correlation Coefficients (ICC) and the 95% Limits of Agreement (LoA) for walking-adaptability outcomes. RESULTS: Walking-adaptability outcomes differed in to-be-expected directions for subgroups stratified for fall frequency and leg muscle weakness and for difficulty levels, all reproducible over test occasions. Correlations between walking-adaptability and balance outcomes were mainly low (r < 0.587). Ceiling effects were present for anticipatory obstacle-avoidance and balance outcomes, but not for reactive obstacle avoidance. ICCs [95% confidence intervals] were good for the challenging 20% (0.80[0.67-0.88]) and 30% target-stepping conditions (0.74[0.57-0.85]) and for the reactive obstacle-avoidance (0.76[0.59-0.86]) condition, but not for 0% target-stepping and anticipatory obstacle-avoidance (ICC<0.62) conditions. Likewise, the narrowest LoA were observed for the 20% and 30% target-stepping conditions. SIGNIFICANCE: We proved face, construct and content validity of C-Mill walking-adaptability assessment in polio survivors with a history of falls and/or fear of falling. Adding walking-adaptability assessment, particularly the more challenging tests given their superior reproducibility, to currently used clinical tests could improve fall-risk evaluation in this population.

Use and Usability Of Custom-Made Knee-Ankle-Foot Orthoses In Polio Survivors with Knee Instability: A Cross-Sectional Survey.

OBJECTIVE: To investigate the use of custom-made knee-ankle-foot orthoses in daily life and differences in usability factors of knee-ankle-foot orthoses between users and discontinued users. DESIGN: Cross-sectional survey study. SUBJECTS: A total of 163 polio survivors provided with a knee-ankle-foot orthosis at an outpatient clinic of a university hospital. METHODS: Use and usability of knee-ankle-foot orthoses in daily life were assessed with a postal questionnaire. Usability factors were formulated using the International Organization for Standardization (ISO) 9241-11 standard. RESULTS: A total of 106 respondents (65%) returned the questionnaire. Of these, 98 were eligible for analysis. Seventy-four respondents (76%) reported using their knee-ankle-foot orthosis. Compared with discontinued users (24%), users experienced more limitations when walking without an orthosis (p = 0.001), were more often experienced with wearing a previous orthosis (p < 0.001) and were more often prescribed with a locked rather than a stance-control knee-ankle-foot orthosis (p = 0.015). Furthermore, users reported better effectiveness of their knee-ankle-foot orthosis (p < 0.001), more satisfaction with goals of use and knee-ankle-foot orthosis-related aspects (p < 0.001). CONCLUSION: The majority of polio survivors used their custom-made knee-ankle-foot orthoses in daily life. Factors related to continued use, such as walking ability without orthosis, expectations of the orthosis, previous orthosis experience and type of knee-ankle-foot orthosis provided, should be considered and discussed when prescribing a knee-ankle-foot orthosis in polio survivors.

Individual stiffness optimization of dorsal leaf spring ankle-foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations.

BACKGROUND: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier's recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. METHODS: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. RESULTS: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (- 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s, p = 0.003). Additionally, a larger ankle range of motion (+ 1.3 ± 0.3 degrees, p < 0.001) and higher ankle power (+ 0.16 ± 0.04 W/kg, p < 0.001) were found with the experimentally optimized stiffness compared to the supplier recommended stiffness. CONCLUSIONS: In people with calf muscle weakness, current supplier's recommendations for the CA7 stiffness level result in the provision of DLS-AFOs that are too stiff and only achieve 80% of the reduction in energy cost achieved with an individual optimized stiffness. It is recommended to experimentally optimize the CA7 stiffness in people with calf muscle weakness in order to maximize treatment outcomes. Trial registration Nederlands Trial Register 5170. Registration date: May 7th 2015. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5170 .

Polio survivors have poorer walking adaptability than healthy individuals.

BACKGROUND: Falling is a major health problem in polio survivors, often occurring as a result of tripping, slipping or misplaced steps. Therefore, reduced walking adaptability possibly plays an important role. RESEARCH QUESTION: Does walking adaptability, assessed on an interactive treadmill, differ between polio survivors and healthy individuals? METHODS: In this cross-sectional study, 48 polio survivors with at least one reported fall in the past year and/or fear of falling and 25 healthy individuals of similar age walked at self-selected comfortable fixed speed on an instrumented treadmill. Walking adaptability was measured as i) target-stepping accuracy (determined as variable error [VE] in mm independent of speed) in three conditions; 0 %, 20 % and 30 % variation in step length and width, and ii) anticipatory and reactive obstacle avoidance (ObA and ObR, in percentage successfully avoided). All trials were checked for valid step detection. RESULTS: 46 polio survivors (mean ± SD age: 63.2 ± 8.7 years) and 25 healthy individuals (64.3 ± 6.6 years, p = 0.585) showed valid step detection. Compared to healthy individuals (mean±SE VE: 30.6±1.2 mm), polio survivors stepped less accurately onto targets (36.4±0.9 mm, p = 0.001), especially with their least-affected leg. Polio survivors avoided fewer obstacles successfully (mean±SE ObA: 83±3 %, ObR: 59±4 %) than healthy individuals (100±0.3 %, p < 0.001 and 94±3 %, p < 0.001, respectively), with a stronger decline in success rates from anticipatory to reactive obstacle avoidance for polio survivors (p < 0.001). SIGNIFICANCE: Polio survivors reporting falls and/or fear of falling had a demonstrably reduced walking adaptability, especially so for reactive obstacle avoidance, which requires step adjustments under high time-pressure demands. Future research should study the merit of walking-adaptability assessment to currently used clinical methods of fall-risk assessment within this population.

Production Time and User Satisfaction of 3-Dimensional Printed Orthoses For Chronic Hand Conditions Compared With Conventional Orthoses: A Prospective Case Series.

OBJECTIVE: Hand orthoses are often prescribed for persons with chronic hand and wrist impairments. This study assessed the feasibility, in terms of production time and user satisfaction, of 3-dimensional printed hand orthoses compared with conventional hand orthoses for this population. METHODS: In this prospective case series, both a conventional hand orthosis and a 3-dimensional printed hand orthosis were manufactured for 10 participants. Production time (in minutes) of each orthosis was recorded. Each orthosis was worn for one week, after which participants completed a self-designed questionnaire on satisfaction, scored on a 5-point Likert scale. Functionality and orthosis preference were also assessed. RESULTS: The mean (standard deviation (SD)) production time for the 3-dimensional printed orthoses, of 112 (11.0) min, was significantly shorter compared with 239 (29.2) min for the conventional orthoses (95% confidence interval (95% CI) 71-182 min, p = 0.001). Satisfaction scores were similar for both orthoses, except for comfort item "fitting method", which was rated significantly higher for scanning compared with casting (median [IQR] score: 5 [0.0]; 4 [2.0], p = 0.034). Functionality and orthosis preference were rated similar for both orthoses. CONCLUSION: As the production time was halved, user satisfaction similar, and scanning experienced as slightly more comfortable than casting, 3-dimensional printed hand orthoses seem feasible and potentially beneficial for use in people with chronic hand and wrist impairments.

Individualized Aerobic Exercise in Neuromuscular Diseases: A Pilot Study on the Feasibility and Preliminary Effectiveness to Improve Physical Fitness.

OBJECTIVE: Clear guidelines to prescribe aerobic exercise in neuromuscular diseases (NMD) are lacking, which hampers effective application in neuromuscular rehabilitation. This pilot study evaluated the feasibility and preliminary effectiveness of an individualized aerobic exercise program according to a recently developed training guide (B-FIT) to improve physical fitness in individuals with NMD. METHODS: Thirty-one individuals who were ambulatory and had 15 different slowly progressive NMD participated in a 4-month, polarized, home-based, aerobic exercise program. The program included 2 low-intensity sessions and 1 high-intensity session per week. Feasibility outcomes were the following: completion rate, proportion of followed sessions, adverse events, and participant and therapist satisfaction based on a self-designed questionnaire. Submaximal incremental exercise tests were used to assess the effects on physical fitness. RESULTS: Twenty-six participants (84%) completed the B-FIT program, and the proportion of followed sessions was >75%. Three adverse events were reported and resolved. Regarding satisfaction, participants (based on n = 9) reported feeling fitter, but training was considered insufficiently challenging. Physical therapists (n = 5) reported that B-FIT provides a clear, well-grounded guidance. They perceived the time investment for initiating the program and the carry-over to primary care as the main barriers. The mean (SD) submaximal heart rate (based on n = 20) reduced significantly by -6.5 beats per minute (95% CI = -11.8 to -1.2), from 121.7 (16.5) at baseline to 115.2 (14.3) after intervention. Submaximal ratings of perceived exertion, anaerobic threshold, and peak workload also improved significantly (P < .05). CONCLUSION: The outcomes of this pilot study suggest that individualized aerobic exercise according to B-FIT is feasible and has potential to improve physical fitness in a wide variety of slowly progressive NMD. However, some barriers must be addressed before investigating the efficacy in a randomized controlled trial. IMPACT: The outcomes of this study demonstrate the feasibility of individualized aerobic exercise according to the B-FIT training guide and the potential to improve physical fitness in NMD. Physical therapists indicated that the use of B-FIT provides a clear, well-grounded guidance. The training guide can support health care professionals in the application of aerobic exercise in adult neuromuscular rehabilitation. LAY SUMMARY: Individualized exercise according to the B-FIT training guide is feasible in a wide variety of slowly progressive NMD and might help improve physical fitness.