Calf Muscle Weakness Research Articles

Effects of gait variability training following ankle-foot-orthosis provision in three individuals with bilateral calf muscle weakness due to neuromuscular disorders

Effects of gait variability training following ankle-foot-orthosis provision in three individuals with bilateral calf muscle weakness due to neuromuscular disorders

Evaluating the effectiveness of Baker's procedure in restoring functionality in neglected Achilles tendon injuries

Background: Neglected Achilles tendon injuries present a significant challenge in orthopedic practice, often requiring complex surgical interventions for effective treatment. This study aims to evaluate the functional outcomes of patients with neglected Achilles tendon injuries treated using Baker's procedure, a surgical technique designed for complex cases. Methods: This prospective interventional study was conducted at multiple medical centers in Dhaka, Bangladesh, from January 1, 2012, to May 31, 2013. It included 42 patients aged 18 to 60 years with signs of old Tendo-Achilles rupture. Participants were selected based on specific inclusion and exclusion criteria and underwent Baker's Procedure. Postoperative assessments included pain levels, ankle stiffness, calf-muscle weakness, footwear restrictions, range of motion, and patient satisfaction, evaluated using the Juhana Leppilahti modified score. Result: The majority of patients (85.71%) reported no pain post-treatment, while 14.29% experienced mild pain. Ankle stiffness was absent in 71.43% of the patients and mild in 28.57%. Calf-muscle weakness varied, with 64.29% showing no weakness, 28.57% mild weakness, and 7.14% moderate weakness. Footwear restrictions were minimal, with 92.86% reporting no restrictions. Active range of motion was normal (≤5°) in 64.29% of patients and mildly limited (6-10°) in 35.71%. Patient satisfaction was high, with 71.43% being 'Very satisfied' with their treatment outcomes. Conclusions: The study demonstrates that Baker's Procedure is an effective surgical intervention for neglected Achilles tendon injuries, leading to significant pain relief, restored functional mobility, and high patient satisfaction. These findings suggest that with appropriate surgical and rehabilitative care, patients with complex Achilles tendon injuries can achieve favorable outcomes, emphasizing the importance of tailored surgical approaches in orthopedic practice.

New mutation within a common haplotype is associated with calf muscle weakness in Holsteins

A recessive haplotype resulting in elevated calf mortality but with apparent incomplete penetrance was previously linked to the end of chromosome 16 (78.7-80.7 Mbp). Genotype analysis of 5.6 million Holsteins indicated that the haplotype was common and traced back to 1952, with a key ancestor born in 1984 (HOUSA1964484, Southwind) identified from chip genotypes as homozygous for the suspect haplotype. Sequence data from Southwind (an affected calf) and the sire of the affected calf were scanned for candidate mutations. A missense mutation with a deleterious projected impact at 79,613,592 bp was homozygous in the affected calf and heterozygous in the calf's sire and Southwind. Sequence data available from the Cooperative Dairy DNA Repository for 299 other Holsteins indicated a 97% concordance with the haplotype and an 89% call rate. The exon amino acid sequence appears to be broadly conserved in the CACNA1S gene, and mutations in humans and mice can cause phenotypes of temporary or permanent paralysis analogous to those in calves with the haplotype causing muscle weakness (HMW). Improved methods for using pedigree to track new mutations within existing haplotypes were developed and applied to the haplotypes for both muscle weakness and Holstein cholesterol deficiency (HCD). For HCD, concordance of the gene test with its haplotype status was greatly improved. For both defects, haplotype status was matched to heifer livability records for 558,000 calves. For HMW, only 46 heifers with livability records were homozygous and traced only to Southwind on both sides. Of those, 52% died before 18 mo at an average age of 1.7 ± 1.6 mo, but that death rate may be underestimated if only healthier calves were genotyped. The death rate was 2.4% for noncarriers. Different reporting methods or dominance effects may be needed to include HMW and other partially lethal effects in selection and mating. Direct tests are needed for new mutations within existing common haplotypes because tracking can be difficult even with accurate pedigrees when the original haplotype has a high frequency.

Incidents of Complications after Reconstruction of Neglected Achilles Tendon Injury by Baker's Procedure

Introduction: Neglected Achilles tendon ruptures present a significant challenge in orthopedic surgery, with varied outcomes and complications. This study aims to evaluate the effectiveness of Baker's Procedure in the reconstruction of neglected Achilles tendon ruptures and to analyze the associated postoperative outcomes and complications. Methods: This prospective interventional study was conducted from January 1, 2012, to May 31, 2013, at multiple centers in Dhaka, Bangladesh. It included 42 patients aged 18 to 60 years with neglected Tendo-Achilles ruptures, defined as injuries untreated for over 4 weeks. Baker's Procedure, involving gastrocnemius aponeurosis advancement, was employed for reconstruction. Result: Of the 42 participants, 71.43% were male, with a mean age of 30.7 years. Injuries predominantly occurred in the right Achilles tendon (57.14%) and were mainly caused by sharp-metal objects (57.14%) and toilet-pan accidents (35.71%). Postoperative complications included stitch or wound infections (21.43%), pain (14.29%), stiffness (28.57%), and calf-muscle weakness (35.71%). Excellent, good, and fair outcomes were achieved in 64.29%, 21.43%, and 14.29% of patients, respectively. Conclusion: Baker’s Procedure is effective in reconstructing neglected Achilles tendon ruptures, with a majority of patients achieving excellent or good outcomes. However, the relatively high rate of postoperative complications, particularly infections, calf muscle weakness and stiffness, highlights the need for improved surgical and postoperative strategies. These findings underscore the importance of tailored.

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

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. To examine the effectiveness of specialist care orthoses compared to usual care orthoses on personal goal attainment and walking ability. Cohort study. 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. 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. 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). 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.

Gait stability in relation to energy cost of walking in polio survivors with unilateral calf muscle weakness

Gait stability in relation to energy cost of walking in polio survivors with unilateral calf muscle weakness

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

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

Individual stiffness optimization of dorsal leaf spring ankle\u2013foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations

BackgroundIn 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.MethodsThirty-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.ResultsIn 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.ConclusionsIn 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.

Stiffness-Optimized Ankle-Foot Orthoses Improve Walking Energy Cost Compared to Conventional Orthoses in Neuromuscular Disorders: A Prospective Uncontrolled Intervention Study.

In persons with calf muscle weakness, walking energy cost is commonly increased due to persistent knee flexion and a diminished push-off. Provided ankle-foot orthoses (AFOs) usually lower walking energy cost. To maximize the reduction in energy cost, AFO bending stiffness should be individually optimized, but this is not common practice. Therefore, we aimed to evaluate whether individually stiffness-optimized AFOs reduce walking energy cost compared to conventional AFOs in persons with non-spastic calf muscle weakness and, secondarily, whether stiffness-optimized AFOs improve walking speed and gait biomechanics. Thirty-seven persons with non-spastic calf muscle weakness using a conventional AFO were included. Participants were provided a new, individually stiffness-optimized AFO. Walking energy cost, speed and gait biomechanics were assessed, at delivery and 3-months follow-up. Stiffness-optimized AFOs reduced walking energy cost with 9.2% (-0.42J/kg/m, 95%CI: 0.26 to 0.57) compared to the conventional AFOs while walking speed increased with 5.2% (+0.05m/s, 95%CI: 0.03 to 0.08). In bilateral affected persons the effects were larger compared to unilateral affected persons (difference effect energy cost: 0.31J/kg/m, speed: +0.09m/s). Although individually gait biomechanics changed considerably, no significant group differences were found (p > 0.118). We demonstrated that individually stiffness-optimized AFOs considerably and meaningfully reduced walking energy cost compared to conventional AFOs, which was accompanied by an increase in walking speed. Especially in bilateral affected persons large effects of stiffness-optimization were found. The individual differences in gait changes substantiate the recommendation that the AFO bending stiffness should be individually tuned to minimize walking energy cost.

Use and usability of custom-made dorsiflexion-restricting ankle-foot orthoses for calf muscle weakness in polio survivors: a cross-sectional survey.

Dorsiflexion-restricting ankle-foot orthoses (DR-AFOs) are often prescribed in polio survivors with calf muscle weakness to reduce or solve gait problems. However, orthoses are sometimes not being used and/or users are dissatisfied with the usability. To compare the usability of custom-made DR-AFOs provided in clinical care between users and discontinued users who have calf muscle weakness due to polio. Cross-sectional survey. Outpatient post-polio university hospital clinic in the Netherlands. All polio survivors with calf muscle weakness, provided with a DR-AFO between 2004 and 2015 in our outpatient clinic. DR-AFO use and usability according to the ISO 9241-11 standard were evaluated with a questionnaire sent out by postal mail. Forty of 57 questionnaires were returned. Five respondents did not fulfil the eligibility criteria. DR-AFO use among the 35 eligible respondents was 74%. Compared to discontinued users, users were significantly more often male (users: 16 of 26 vs. discontinued users: 0 of 9, P=0.001), more limited in their walking ability without DR-AFO (P=0.007), perceived more effectiveness, both overall (P=0.001) and on their personal goals of use (P=0.006), and were more satisfied with orthosis-related aspects (P=0.011), such as comfort. Almost three quarters of the polio survivors used their orthosis. Use was related to several aspects of usability, indicating that it is important to consider usability in the prescription process of DR-AFOs for polio survivors with calf muscle weakness. When prescribing DR-AFOs, it is important to consider that the orthosis is most likely used when the experienced walking problems are large and the DR-AFO reduces these problems. We recommend discussing the patient's personal goals for DR-AFO use and the anticipated improvement on the individual's walking problems as well as possible hindrance of the orthosis during daily life activities. Furthermore, providers may need to pay extra attention to females and should particularly take care that the experienced fit and comfort are satisfactory. Incorporating these suggestions in clinical practice may further improve DR-AFO use among polio survivors with calf muscle weakness.

Impact of Physiotherapy on the Calf Muscle Torque Variability after Achilles Tendon Rupture

It has been established that muscle torque variability determines movement stability during the task [1]. Calf muscle weakness, ankle range of motion reduction and postural misbalance are common pathological limitations after Achilles tendon rupture (ATR). Most studies analyse rehabilitation influence for muscle strength and body balance, but there is a lack of information about calf muscle torque variability. The aim of the study was to determine ankle plantar flexion and dorsal flexion muscle maximal voluntary contraction torque and variability Q. Organization and methods. We measured five males, (aged 29 ± 6) after 6.5 – week surgery of ATR. Participants performed isometric ankle flexion and extension force with injured and non-injured legs. Muscles maximal voluntary contraction (MVC) torque and torque variability were measured at –15°; 0°; 15° angles. The variability of target force was 20% of MVC torque. Rehabilitation programme consisted of balance, muscle strength and stretching exercises. Calf muscle MVC torque and variability were observed before and after 8-week rehabilitation. The results of the research. We determined that after physiotherapy the injured and the non-injured leg isometric ankle flexion and extension muscle MVC torque increased and muscle torque variability decreased.Keywords: muscle torque variability, isometric maximal voluntary contraction torque, rehabilitation suformavimas.

Description of orthotic properties and effect evaluation of ankle-foot orthoses in non-spastic calf muscle weakness.

To describe the orthotic properties and evaluate the effects of ankle-foot orthoses for calf muscle weakness in persons with non-spastic neuromuscular disorders compared with shoes-only. Cross-sectional study. Thirty-four persons who used ankle-foot orthoses for non-spastic calf muscle weakness. The following orthotic properties were measured: ankle-foot orthosis type, mass, and ankle and footplate stiffness. For walking with shoes-only and with the ankle-foot orthoses, walking speed, energy cost and gait biomechanics were assessed. Four types of ankle-foot orthosis were identified: shaft-reinforced orthopaedic shoes (n = 6), ventral ankle-foot orthoses (n = 10), dorsal leaf ankle-foot orthoses (n = 12) and dorsiflexion-stop ankle-foot orthoses (n = 6). These types differed significantly with regards to mass, ankle-and footplate stiffness. Compared with shoes-only, all ankle-foot orthoses/orthopaedic shoes groups combined increased walking speed by 0.18 m/s (95% confidence interval (95% CI) 0.13-0.23), reduced energy cost by 0.70 J/kg/m (95% CI 0.48-0.94) and limited ankle dorsiflexion by -3.0° (95% CI 1.3-4.7). Higher ankle-foot orthoses ankle stiffness correlated with greater reductions in walking energy cost and maximal ankle dorsiflexion angle. Ankle-foot orthoses for persons with non-spastic calf muscle weakness vary greatly in properties and effects on gait. The large variation in effectiveness may be due to differences in ankle stiffness, although this requires further prospective evaluation.

Modifying ankle foot orthosis stiffness in patients with calf muscle weakness: gait responses on group and individual level

BackgroundTo improve gait, persons with calf muscle weakness can be provided with a dorsal leaf spring ankle foot orthosis (DLS-AFO). These AFOs can store energy during stance and return this energy during push-off, which, in turn, reduces walking energy cost. Simulations indicate that the effect of the DLS-AFO on walking energy cost and gait biomechanics depends on its stiffness and on patient characteristics. We therefore studied the effect of varying DLS-AFO stiffness on reducing walking energy cost, and improving gait biomechanics and AFO generated power in persons with non-spastic calf muscle weakness, and whether the optimal AFO stiffness for maximally reducing walking energy cost varies between persons.MethodsThirty-seven individuals with neuromuscular disorders and non-spastic calf muscle weakness were included. Participants were provided with a DLS-AFO of which the stiffness could be varied. For 5 stiffness configurations (ranging from 2.8 to 6.6 Nm/degree), walking energy cost (J/kg/m) was assessed using a 6-min comfortable walk test. Selected gait parameters, e.g. maximal dorsiflexion angle, ankle power, knee angle, knee moment and AFO generated power, were derived from 3D gait analysis.ResultsOn group level, no significant effect of DLS-AFO stiffness on reducing walking energy cost was found (p = 0.059, largest difference: 0.14 J/kg/m). The AFO stiffness that reduced energy cost the most varied between persons. The difference in energy cost between the least and most efficient AFO stiffness was on average 10.7%. Regarding gait biomechanics, increasing AFO stiffness significantly decreased maximal ankle dorsiflexion angle (− 1.1 ± 0.1 degrees per 1 Nm/degree, p < 0.001) and peak ankle power (− 0.09 ± 0.01 W/kg, p < 0.001). The reduction in minimal knee angle (− 0.3 ± 0.1 degrees, p = 0.034), and increment in external knee extension moment in stance (− 0.01 ± 0.01 Nm/kg, p = 0.016) were small, although all stiffness’ substantially affected knee angle and knee moment compared to shoes only. No effect of stiffness on AFO generated power was found (p = 0.900).ConclusionsThe optimal efficient DLS-AFO stiffness varied largely between persons with non-spastic calf muscle weakness. Results indicate this is caused by an individual trade-off between ankle angle and ankle power affected differently by AFO stiffness. We therefore recommend that the AFO stiffness should be individually optimized to best improve gait.Trial registration numberNederlands Trial Register 5170. Registration date: May 7th 2015. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5170

Optimizing ankle foot orthosis stiffness substantially improves energy cost compared to usual orthotic care in persons with calf muscle weakness

Postural stability depends on the integration of the multisensory system to produce motor outputs. When visual and somatosensory input is reliable, this reduces reliance on the vestibular system. Despite this, vestibular loss can still cause severe postural dysfunction. Training one or more of the three sensory systems through vestibular habituation and adaptation can alter sensory weighting and change postural behavior.The purpose of this study was to assess sensory reweighting of postural control processing after combined vestibular activation with voluntary weight shift training in healthy adults.Thirty-three healthy individuals (18–35 y.o.) were randomly assigned to one of three groups: No training (control), visual feedback weight shift training (WST) coupled with an active horizontal headshake (HS) activity to elicit a vestibular perturbation, or the same WST without HS (NoHS). Training was performed 2x/day, every other day (M, W, F), totaling six sessions. Pre- and post- assessments on the Sensory Organization Test (SOT) were performed. Separate between- and within- repeated measures ANOVAs were used to analyze the six SOT equilibrium scores, composite scores, sensory ratios and center of pressure (COP) variables by comparing baseline to post-training. Alpha level was set at p < .05.There was a significant group x session x condition change (p = .012) in the COP multiscale entropy (MSE) velocity sway in the HS group during SOT conditions 5 and 6. Similarly, COP medio-lateral standard deviation sway (ML Std) showed group x session x visual condition (p = .028), due to HS in condition 6 relative to other two groups.Postural training can alter sensory organization after a visual feedback-vestibular activation training protocol, suggesting a possible sensory reweighting through vestibular adaptation and/or habituation.Translating these findings into a vestibular-impaired population can stimulate the design of a rehabilitation balance protocol.

Predictive simulations can validly reproduce the gait pattern of people with non-spastic bilateral calf muscle weakness

Predictive simulations can validly reproduce the gait pattern of people with non-spastic bilateral calf muscle weakness

Stiffness modification of two ankle-foot orthosis types to optimize gait in individuals with non-spastic calf muscle weakness \u2013 a proof-of-concept study

BackgroundTo reduce gait problems in individuals with non-spastic calf muscle weakness, spring-like ankle-foot orthoses (AFOs) are often applied, but they are not individually optimized to treatment outcome. The aim of this proof-of-concept study was to evaluate the effects of modifying the stiffness for two spring-like AFO types with shoes-only as reference on gait outcomes in three individuals with calf muscle weakness due to polio.MethodsWe assessed 3D gait biomechanics, walking speed and walking energy cost for shoes-only and five stiffness conditions of a dorsal-leaf-spring AFO and a spring-hinged AFO. Outcomes were compared between stiffness conditions in the two AFOs and three subjects.ResultsMaximum ankle dorsiflexion angle decreased with increasing stiffness in both AFOs (up to 6–8°) and all subjects. Maximum knee extension angle changed little between stiffness conditions, however different responses between the AFOs and subjects were observed compared to shoes-only. Walking speed remained unchanged across conditions. For walking energy cost, we found fairly large differences across stiffness conditions with both AFOs and between subjects (range 3–15%).ConclusionsModifying AFO stiffness in individuals with non-spastic calf muscle weakness resulted in substantial differences in ankle biomechanics and walking energy cost with no effect on speed. Our results provide proof-of-concept that individually optimizing AFO stiffness can clinically beneficially improve gait performance.

A tropomyosin-receptor kinase-fused gene mutation associates with vacuolar myopathy.

A 44-year-old Caucasian man presented with a 7-year history of upper and lower limb muscle fasciculations and cramps, progressive asymmetric weakness, muscle atrophy, and length-dependent sensory loss. His parents (deceased), 3 older siblings, and 3 children had no history of neurologic symptoms, including weakness and sensory symptoms, with the exception of cramps in the mother. He was not taking any medication known to cause neuropathy or myopathy. On examination, there was right greater than left shoulder girdle muscle weakness and atrophy (Medical Research Council grades 3/5 and 4/5), intrinsic left hand muscle weakness (4+/5) with atrophy, asymmetric pelvic girdle (4/5 right, 3/5 left), and left foot dorsiflexor weakness (4+/5). Strength of neck flexor and extensors, and axial muscles, was normal. He had bilateral calf muscle atrophy and weakness as suggested by his inability to stand on toes (figure, A–C). He was areflexic. Sensory examination revealed distal vibration and pinprick deficits in the upper and lower limbs in a length-dependent fashion. He had bilateral pes cavus. The authors thank the patient for the photographs; Dr. A. Kendler at University of Cincinnati for sharing the muscle biopsy slides; and Invitae for performing the additional analysis of genes associated with myopathies.

Compensations in lower limb joint work during walking in response to unilateral calf muscle weakness

BackgroundPatients with calf muscle weakness due to neuromuscular disorders have a reduced ankle push-off work, which leads to increased energy dissipation at contralateral heel-strike. Consequently, compensatory positive work needs to be generated, which is mechanically less efficient. It is unknown whether neuromuscular disorder patients compensate with their ipsilateral hip and/or contralateral leg; and if such compensatory joint work is related to walking energy cost. Research questionDo patients with calf muscle weakness compensate for the increase in negative joint work by increasing positive ipsilateral hip work and/or positive contralateral leg work? And is the total mechanical work related with walking energy cost? MethodsSeventeen patients with unilateral flaccid calf muscle weakness and 10 healthy individuals performed the following two tests: i) a barefoot 3D gait analysis at comfortable speed and matched control speed (i.e. 0.4 non-dimensional) to assess lower limb joint work and ii) a 6-minute walk test at comfortable speed to assess walking energy cost. ResultsPatients had a lower comfortable walking speed compared to healthy individuals (1.05 vs 1.36 m/s, p < 0.001) and did not increase positive lower limb joint work at comfortable speed. At matched speed (1.25 m/s), patients showed increased positive work at their ipsilateral hip (0.38 ± 0.08 vs 0.27 ± 0.07, p = 0.001) and/or contralateral leg (0.99 ± 0.14 vs 0.69 ± 0.14, p < 0.001). Patients with weakest plantar flexors used both strategies. No relation between total positive work and walking energy cost was found (r = 0.43, p = 0.122). SignificancePatients with unilateral calf muscle weakness compensated for reduced ankle push-off work by lowering their comfortable walking speed or, at matched speed, by generating additional positive joint work at the ipsilateral hip and/or contralateral leg. The additional positive joint work at matched speed did not explain the elevated walking energy cost at comfortable speed, which needs further exploration.

Gait patterns in association with underlying impairments in polio survivors with calf muscle weakness

The objective was to identify gait patterns in polio survivors with calf muscle weakness and associate them to underlying lower extremity impairments, which are expected to help in the search for an optimal orthosis.Unilaterally affected patients underwent barefoot 3D-gait analyses. Gait pattern clusters were created based on the ankle and knee angle and ankle moment shown in midstance of the affected limb. Impairment clusters were created based on plantarflexor and knee-extensor strength, and ankle and knee joint range-of-motion. The association between gait patterns and underlying impairments were examined descriptively. The Random Forest Algorithm and regression analyses were used to predict gait patterns and parameters.Seven gait patterns in 73 polio survivors were identified, with two dominant patterns: one with a mildly/non-deviant ankle angle, ankle moment and knee angle (n=23), and one with a strongly deviant ankle angle and a mildly/non-deviant ankle moment and knee angle (n=18). Gait pattern prediction from underlying impairments was 49% accurate with best prediction performance for the second dominant gait pattern (sensitivity 78% and positive predictive value 74%). The underlying impairments explained between 20 and 32% of the variance in individual gait parameters.Polio survivors with calf muscle weakness who present a similar impairment profile do not necessarily walk the same. From physical examination alone, the gait pattern nor the individual gait parameters could be accurately predicted. The patient’s gait should therefore be measured to help in the prescription and evaluation of orthoses for these patients.

Compensatory gait strategies for reduced ankle work in patients with unilateral flaccid calf muscle weakness

Compensatory gait strategies for reduced ankle work in patients with unilateral flaccid calf muscle weakness