Ankle Plantar Flexors Research Articles

Association between knee extensor and ankle plantarflexor muscle thickness and echo intensity with postural sway, mobility and physical function in older adults.

The purpose of this study was to assess the association between muscle thickness and echo intensity of the knee extensors and ankle plantarflexors with postural sway, mobility and physical function in older adults. Twenty-one older men and women (age; 69.9±4.3years) were assessed for postural sway (centre of pressure movement), mobility (i.e. Timed-Up and-Go-test [TUG]), physical function (i.e. 5 times sit-to-stand [STS]), and ultrasound derived measures of muscle thickness and echo intensity of the vastus lateralis (VL) and gastrocnemius medialis (GM). Significant inverse correlations were observed between VL and GM thickness with TUG (r=-0.432 to -0.492) and STS (r=-0.473 to -0.596). Significant positive correlations were observed between VL and GM echo intensity with TUG (r=0.459 to 0.518) and STS (r=0.481 to 0.635). Significant positive correlations were also detected between GM echo intensity and anteroposterior sway (r=0.451 to 0.534). Two key findings emerged from the present experiment. First, this study provides novel evidence that ankle plantarflexor echo intensity, but not thickness, was associated with anteroposterior postural sway among older adults. Second, we provide new evidence that muscle thickness and echo intensity of the knee extensors and uniquely, the ankle plantarflexors, presented with similar magnitude associations with TUG and STS performance in older adults.

Does extracorporeal shock wave therapy decrease spasticity of ankle plantar flexor muscles in patients with stroke: A randomized controlled trial

Objective: To evaluate the effectiveness of radial extracorporeal shock wave therapy on ankle flexor spasticity in stroke survivors and to reveal changes in the fibroelastic components of muscle. Design: Randomized controlled trial. Setting: Inpatient neuro-rehabilitation clinic of a university hospital. Participants: Stroke patients with ankle flexor spasticity. Interventions: Patients were randomized to three groups; radial extracorporeal shock wave therapy, sham, or control. Active and sham therapy were administered two sessions/week for two weeks. All patients received conventional rehabilitation. Main measures: The primary outcome was Modified Ashworth Scale. Secondary outcomes were the Tardieu Scale and elastic properties of plantar flexor muscles assessed by elastography (strain index). All assessments were performed before, immediately after the treatment, and four weeks later at follow-up. Results: Fifty-one participants were enrolled (active therapy n = 17, sham n = 17, control n = 17). Modified Ashworth scores showed a significant decrease in the active therapy group (from 2.47 ± 0.72 to 1.41 ± 0.62) compared to sham (from 2.19 ± 1.05 to 2.06 ± 1.12) and control (from 2.06 ± 0.85 to 2.00 ± 0.73) groups immediately after the treatment (P < 0.001). Tardieu results were also in concordance (P < 0.001), however this effect was not preserved at follow-up. Elastic properties of the ankle flexors were improved in all groups at both assessments after the therapy showing significant decreases in strain index (P < 0.001). However, there was no difference among the groups in terms of improvement in elastography. Conclusion: Radial extracorporeal shock wave therapy has short-term anti-spastic effects on ankle flexor muscles when used as an adjunct to conventional rehabilitation.

Effects of physical-cognitive training on physical and psychological functions among older adults with type 2 diabetes and balance impairment: a randomized controlled trial.

Risks of falls among older adults are multifactorial in nature. A combined training program might be beneficial on fall-related outcomes. This study aimed to explore the effects of group-based physical-cognitive trainings on physical and psychological outcomes among older adults with type 2 diabetes mellitus (T2DM) and balance impairment. Fall incidence were also determined. Thirty-seven older adults with T2DM and balance impairment were randomly assigned to control and intervention groups. The intervention program comprised of 24 training sessions of 45–60 min exercise for 8 weeks. The exercise consisted of warm-up, aerobic exercise by nine square stepping, resistance exercise combined with cognitive training and cool down. All participants were assessed at baseline, 4 and 8 weeks after intervention, and 1-year follow-up. Both groups reported similar rates of falls. Global cognition, depressive symptoms, and fear of falling did not differ between groups at any time. The Timed Up & Go (TUG) test, alternate stepping test (AST), knee extensors, ankle plantarflexors, and dorsiflexors strength differed at 4 weeks. TUG, AST, hip abductors, knee flexors, ankle plantarflexors, and dorsiflexors strength differed at 8 weeks. The activity of daily living (ADL), TUG test (P=0.002) and AST, hip extensors and abductors, knee extensors and flexors, ankle plantarflexors and dorsiflexors were different at 1-year follow-up. The group-based physical-cognitive training could benefit older adults with T2DM in terms of maintaining ADL. The intervention could reduce fall risk factors by improving balance and lower limb muscle strength among older adults with T2DM and balance impairment.

Rounding the base: A lower extremity biomechanical analysis in softball players

Contacting the base is a common injury mechanism for base runners in softball, with ankle sprains being the most common type of injury, but it is not known how the base affects lower extremity mechanics. The purpose of this study was to analyze lower extremity biomechanics while rounding a base. Sixteen recreationally active females with previous softball experience completed two base rounding conditions. A base was securely placed on the force place for the with base (WB) condition, and an outline of the base was taped on the force plate for the no base (NB) condition. Three-dimensional right-leg hip, knee, and ankle kinematics and kinetics were measured during the stance phase of the base rounding and analyzed using statistical parametric mapping (SPM). The WB condition resulted in decreased hip abduction ( p = 0.034), increased dorsiflexion ( p = 0.012), and decreased inversion ( p &lt; 0.001) angles. Increased hip extension ( p &lt; 0.001) and hip abduction ( p = 0.016) moments were exhibited during the WB condition. Decreased hip abduction ( p = 0.026), ankle plantarflexor ( p &lt; 0.001), and ankle eversion ( p &lt; 0.001) moments were also exhibited in the WB condition. The base acts as a lateral banking surface, reducing variables associated with ankle sprains, and likely assists in propelling base runners to the next base without injury.

Biomechanical Parameters that May Influence Lower Limb Injury during Landing in Taekwondo

Background and Objectives: The jumping kick of Taekwondo was a unilateral exercise that repeatedly moves in one direction. The exercise was exposed to the risk of injury due to the heavy ground reaction force and load in the landing. The first purpose of this study was to compare the impact force (IF), peak vertical ground reaction force (PVGRF), vertical loading rate (VLR), vertical stiffness (VS), and landing foot angle (LFA) during the landing of the jumping kick according to the experience of lower injury. The second purpose of this study was to investigate the lower extremities’ strength and the bilateral/ipsilateral asymmetry between the groups; Material and Methods: Ten injury-experience athletes (IG, age: 21.0 ± 0.8 years; height: 170.5 ± 4.1 cm; body weight: 66.7 ± 6.0 kg; career: 8.1 ± 5.0 years) and seven non-injury experience athletes (NG, age: 22.9 ± 4.0 years; height: 173.4 ± 3.1 cm; body weight: 67.9 ± 7.9 kg; career: 8.3 ± 5.0 years) participated; Results: There was no statistical difference between the two groups in the landing and lower extremity muscle strength impact variables. However, in the bilateral asymmetry of the ankle plantar flexor and the ipsilateral asymmetry of the hip abductor/adductor, IG was statistically larger than NG (p < 0.05). The landing foot angle also showed negative correlation to all impact variables (IF, PVGRF, VLR, and VS) (p < 0.05); Conclusions: It is desirable to place the landing foot down at a wide angle to prevent injury in performing Taekwondo jumping kicks. Although NGs have been shown to have better muscle strength symmetry and balance in some areas compared to IG, further research is needed to determine whether they are effective in preventing injury.

Clinical Assessment and Pedobarographic Analysis after Radial Shock Wave Therapy of Ankle Plantar Flexor Spasticity in Stroke

Objective: Radial shock wave therapy (RSWT) has increasingly been utilized in the treatment of spasticity recently. The purpose of the current study is to assess the effectiveness of RSWT in the treatment of ankle plantar flexor muscles spasticity of stroke patients by pedobarography and clinical evaluation.&#x0D; Materials and Methods: A total of 23 stroke patients were enrolled into the study. Patients received an initial sham treatment of RSWT, followed by three separate interventional sessions received one week apart. Treatment success was assessed using the Modified Ashworth Scale (MAS), ankle passive range of motion (pROM) measurement and pedobarography.&#x0D; Results and Discussion: No significant change was observed in clinical and pedobarographic values following sham RSWT. In the intervention group, however, MAS decreased from3.34±0.7 to 2.39±0.89 after a single RSWT session and to 2.04±0.92 first week and to 2.52±0.89 fourth week after three RSWT sessions. As a result of the study, heel peak pressure and total plantar contact area were improved. In particular, three RSWT sessions were more effective than single RSWT session.&#x0D; Conclusions: We observed a significant improvement in plantar flexor spasticity in stroke patients after both a single and three RSWT sessions and this improvement persisted during the four-week study period.&#x0D; Bangladesh Journal of Medical Science Vol.20(3) 2021 p.586-593

Muscle Force Patterns in Lower Extremity Muscles for Elite Discus Throwers, Javelin Throwers and Shot-Putters - A Case Study.

Optimal release variables, as well as the kinematics and kinetics of athletes, are crucial for the maximization of throwing distance in athletics. Mathematical models and simulations allow throwing techniques to be studied. However, muscle force patterns and the contribution of specific muscle groups in athletics throwing events are not well understood and require detailed research. In this study, important variables of the muscle force generated during the javelin, discus and shot put events were determined using OpenSim software. Musculoskeletal simulations were carried out based on kinematic and kinetic data collected using the Vicon system and Kistler plates with the help of nine top Polish athletes (three in each event). OpenSim software was used to calculate muscle forces and joint velocities. For each discipline, it was found that the main muscle groups involved in the throwing movement were better at distinguishing throwers than joint velocities. The contribution of right ankle plantar flexors at the beginning of the final acceleration phase as well as left hip extensors at the end of the final acceleration phase was given special attention. This work provides a better understanding of the techniques used in athletics throws. Musculoskeletal simulations of throwing styles might help coaches analyze the techniques of individual athletes, resulting in better adjustment of training programmes and injury prevention protocols.

The Effects of Static Stretching On Dynamic Postural Control During Maximum Forward Leaning Task

The purpose of this study was to determine how the application of static stretching to ankle plantar flexors affects postural control during maximum forward leaning. Twenty-six volunteer males (age 21.4 ± 1.2 years) were randomly assigned to stretching and control conditions. Participants conducted 5-min stretching on a stretch board for the stretching condition and were kept standing for 6-min for the control condition. Before and after intervention, the range of motion (ROM) at ankle dorsiflexion and the center of pressure (COP) excursion during maximal forward leaning were determined. Mean anteroposterior COP position, COP velocity and COP areas were calculated to compare the change in postural control. After stretching, ROM was significantly increased. During maximal forward leaning after stretching, both COP position and velocity showed significant increases compared to before stretching. Moreover, COP position and velocity in the stretching condition were significantly higher than in the control condition after stretching. No significant differences were found in COP area before and after stretching. Five-minute stretching increased not only ROM but also the anterior limit of stability while maintaining posture and led to faster COP shift than before stretching. These results indicate that static stretching would improve dynamic postural control as well.

Effects of whole-body vibration on quadriceps and hamstring muscle strength, endurance, and power in children with hemiparetic cerebral palsy: a randomized controlled study

BackgroundHemiplegic cerebral palsy (CP) enormously affects the quadriceps and hamstring muscles. It causes weakness in the affected lower-extremity muscles in addition to muscle imbalance and inadequate power production, especially in the ankle plantar-flexor and knee extensor muscles. It also causes anomalous delayed myoelectrical action of the medial hamstring. A whole-body vibration (WBV) exercise can diminish muscle spasticity and improve walking speed, muscle strength, and gross motor function without causing unfavorable impacts in adults suffering from CP. Thus, the aim of this study is to investigate the impacts of WBV training associated with conventional physical therapy on the quadriceps and hamstring muscle strength, endurance, and power in children with hemiparetic CP.ResultsThe post-intervention values of the quadriceps and hamstring muscle force, endurance, and power were significantly higher than the pre-intervention values for both groups (p = 0.001). The post-intervention values of the study group were significantly higher than the control group (quadriceps force, p = 0.015; hamstring force, p = 0.030; endurance, p = 0.025; power, p = 0.014).ConclusionThe 8 weeks of WBV training that was added to traditional physical therapy was more successful in improving the quadriceps and hamstring muscle strength, endurance, and power in children with hemiparetic CP when compared to traditional physical therapy alone.

Increased Ankle Plantar Flexor Stiffness Is Associated With Reduced Mechanical Response to Stretch in Adults With CP

Hyperexcitable stretch reflexes are often not present despite of other signs of spasticity in people with brain lesion. Here we looked for evidence that increased resistance to length change of the plantar flexor muscle-fascicles may contribute to a reduction in the stretch reflex response in adults with cerebral palsy (CP). A total of 17 neurologically intact (NI) adults (mean age 36.1; 12 female) and 13 ambulant adults with CP (7 unilateral; mean age 33.1; 5 female) participated in the study. Subjects were seated in a chair with the examined foot attached to a foot plate, which could be moved by a computer-controlled electromotor. An ultrasound probe was placed over the medial aspect of the leg to measure the length of medial gastrocnemius muscle fascicles. Slow (7 deg/s) and fast (200 deg/s) stretches with amplitude 6 deg of the plantar flexors were applied over an ankle range of 70 deg at 10 deg intervals between 60 and 130 deg plantarflexion. It was checked by EMG electrodes that the slow stretches were sufficiently slow not to elicit any activity and that the fast stretches were sufficiently quick to elicit a maximal stretch reflex in both groups. The torque elicited by the stretches was measured together with changes in the length of medial gastrocnemius muscle fascicles. Muscle fascicles increased significantly in length with increasing dorsiflexion position in both populations (p < 0.001), but the fascicles were shorter in the CP population at all positions. Slow stretches elicited significantly larger torque and significantly smaller length change of muscle fascicles as the ankle joint position was moved more towards dorsiflexion in CP than in NI (p < 0.001). Fast stretches elicited larger torque responses at ankle joint positions of 80–100 deg in the NI than in the CP group (p < 0.01). A significant negative correlation was observed between the torque response and muscle fascicle length change to slow stretch in CP (p < 0.05), but not in NI. These findings support that increased passive resistance of the ankle plantar flexor muscle-tendon unit and development of contractures may conceal stretch reflex response in adults with CP. We argue that this should be taken into account in the neurological examination of spasticity.

Levodopa facilitates improvements in gait kinetics at the hip, not the ankle, in individuals with Parkinson's disease

Parkinson’s disease symptoms impair gait, limit mobility, and reduce independence. Levodopa improves muscle activation, strength, and coordination; thus, facilitating increased step length, but few studies have evaluated the underlying forces associated with medication-induced gait improvements. Here, we assess the effects of levodopa on gait kinetics in persons with Parkinson’s disease. Over two sessions, 13 participants with Parkinson’s disease walked on a treadmill while both optimally medicated and after a 12-hour medication withdrawal. Walking was analyzed for spatiotemporal parameters, ranges of motion, anterior-posterior ground reaction forces, joint torques, and powers using an instrumented treadmill and motion capture system. When on medication, participants increased gait speed by significantly improving step length (p = .009) and time (p = .004). Peak propulsive force (p = .001) and hip flexion torques (p = .003) increased with medication while hip extensor and ankle plantarflexor torques did not. While differences in joint power were not significantly different, the optimal medication condition showed medium to large effects, with the largest effect at the hip (dz = 0.84). Our findings suggest the underlying forces responsible for the increases in gait speed are primarily due to increases at the hip, with limited change at the ankle. Disproportionate use of muscle force may be a limiting factor for levodopa’s use as an intervention for walking. Future interventions should consider targeting force production deficits during gait in those with Parkinson’s disease.

The Effects of Lower Extremity Muscle Fatigue on Dynamic Balance in Volleyball Players

Objectives: Lower extremity muscles are critical for maintaining dynamic balance and athletic performance. Fatigue of these muscles may affect dynamic balance. It is unclear whether fatigue in a particular muscle group can affect dynamic balance more than that in other groups. This study was conducted to evaluate and compare the effects of fatigue in 5 muscle groups on dynamic balance in volleyball players. Methods: Fifteen healthy male volleyball players separately performed the Star Excursion Balance Test before and immediately after the occurrence of fatigue of ankle Plantar Flexor (PF), knee extensor, knee flexor, hip abductor, and hip adductor muscles. Composite reach distance and distance in anterior, posteromedial, and posterolateral directions were recorded, accordingly. Results: Repeated-measures Analysis of Variance (ANOVA) data indicated that fatigue of all muscle groups significantly decreased the mean score of composite (P&lt;0.001). Anterior, posteromedial, and posterolateral distance scores decreased following muscle fatigue of knee extensors and ankle PFs (P&lt;0.05). Discussion: This study suggested that regarding composite reach score, fatigue of ankle, knee, and hip muscles similarly decreased dynamic balance. However, evaluating three main directions revealed that knee extensors and ankle PFs muscles fatigue presented more prominent effects on the explored volleyball players’ balance, compared to the other muscles.

Factors associated with relative muscle strength in patients with type 2 diabetes mellitus

ObjectivesSome patients with type 2 diabetes mellitus (T2DM) experience decreased mobility associated with lower relative muscle strength (normalized with muscle mass). This study aimed to identify factors predicting relative muscle strength of patients with T2DM assessed at regular clinical visits. MethodsA total of 144 T2DM patients underwent fasting blood drawing (determining white blood cell count [WBC], diabetic kidney disease [DKD], and glycated hemoglobin [HbA1c]) and the assessment of body composition, diabetic peripheral neuropathy (DPN), activity level, and muscle strength (grip, knee extensor, and ankle plantar flexor strength). One-way ANOVA and multiple regression models were used to identify factors associated with the relative muscle strength. ResultsOur data showed that age, diabetes duration, fat percentage, WBC, DPN, and DKD were negatively associated with the relative muscle strength. Specifically, a greater WBC was associated with lower relative muscle strength of both distal and proximal muscle groups of extremities after the adjustment of other associated factors. DPN was associated with lower relative strength of the distal muscle groups of extremities. ConclusionsWBC may be used as a marker of inflammation, and greater count, even within the normal range, is negatively associated with the relative muscle strength in patients with T2DM.

Neurophysiological validation of simultaneous intrinsic and reflexive joint impedance estimates

BackgroundPeople with brain or neural injuries, such as cerebral palsy or spinal cord injury, commonly have joint hyper-resistance. Diagnosis and treatment of joint hyper-resistance is challenging due to a mix of tonic and phasic contributions. The parallel-cascade (PC) system identification technique offers a potential solution to disentangle the intrinsic (tonic) and reflexive (phasic) contributions to joint impedance, i.e. resistance. However, a simultaneous neurophysiological validation of both intrinsic and reflexive joint impedances is lacking. This simultaneous validation is important given the mix of tonic and phasic contributions to joint hyper-resistance. Therefore, the main goal of this paper is to perform a group-level neurophysiological validation of the PC system identification technique using electromyography (EMG) measurements.MethodsTen healthy people participated in the study. Perturbations were applied to the ankle joint to elicit reflexes and allow for system identification. Participants completed 20 hold periods of 60 seconds, assumed to have constant joint impedance, with varying magnitudes of intrinsic and reflexive joint impedances across periods. Each hold period provided a paired data point between the PC-based estimates and neurophysiological measures, i.e. between intrinsic stiffness and background EMG, and between reflexive gain and reflex EMG.ResultsThe intrinsic paired data points, with all subjects combined, were strongly correlated, with a range of r = [0.87 0.91] in both ankle plantarflexors and dorsiflexors. The reflexive paired data points were moderately correlated, with r = [0.64 0.69] in the ankle plantarflexors only.ConclusionAn agreement with the neurophysiological basis on which PC algorithms are built is necessary to support its clinical application in people with joint hyper-resistance. Our results show this agreement for the PC system identification technique on group-level. Consequently, these results show the validity of the use of the technique for the integrated assessment and training of people with joint hyper-resistance in clinical practice.

Tension and trauma releasing exercises for people with multiple sclerosis – An exploratory pilot study

Background and aimMultiple sclerosis (MS) is characterized by increasing symptom burden leading many people with MS to use complementary treatments. TRE (Tension and Trauma Releasing Exercises) is a mind-body therapeutic method aiming to release muscle tension and stress. People with MS (PwMS) have reported benefits from TRE, but no scientific studies have investigated the effects of TRE on PwMS. Aim: To test a TRE program for PwMS and thereby explore outcome measures to be applied in future randomized studies. Experimental procedureA nine-week TRE program was completed by nine participants: Five were women, age ranged from 44 to 66 years, and time since diagnosis ranged from 2 to 21 years. Outcome measures included self-reported day-to-day levels of nine different symptoms as well as sleep quality and stress level. Modified Fatigue Impact Scale (MFIS) fatigue score and spasticity level of the ankle plantar flexors, assessed using a Portable Spasticity Assessment Device (PSAD), were measured pre and post intervention. ResultsDecreases were seen in the mean scores of all nine self-reported day-to-day symptoms as well as stress level, while sleep quality mean score increased. LME analyses showed that all changes were statistically significant except one (bowel dysfunction). Mean MFIS-measured fatigue level decreased significantly from a score of 43.7 (SD = 13.6) to a score of 22.0 (SD = 12.3). No significant change was reported in PSAD-measured spasticity level. ConclusionThe study indicates possible effects of TRE on PwMS on several self-reported outcome measures. Larger, randomized studies should be carried out to explore the findings further.

Habitual endurance running does not mitigate age-related differences in gait kinetics.

Older adults often walk with smaller ankle joint kinetics and larger hip joint kinetics compared to young adults. These age-related differences have been attributed, in part, to weaker plantarflexor muscles. While it is thought that regular physical activity helps to maintain muscle strength and mobility in older adults, physical activity levels on average decline with age. Therefore, understanding the effect of physical activity level on gait kinetics is an important objective for the management of mobility impairment in older adults. The purpose of this study was determine the effect of habitual endurance running on lower-extremity joint kinetics. 12 male older long-term runners (67±5yrs., 1.79±0.07m, 77.3±13.7kg) and 12 male older non-runners (70±3yrs., 1.78±0.06m, 79.68±10.6kg), performed overground walking trials at 1.3m/s while kinematic and kinetic data were collected. Participants also performed maximal voluntary contractions at the hip, knee, and ankle joints on an isokinetic dynamometer. Older runners displayed similar ankle plantarflexor strength, similar hip extensor strength, and greater knee extensor strength compared to older non-runners, and walked with similar ankle joint kinetics (p>0.05), and larger hip joint kinetics compared to older non-runners (p<0.05). Thus, physical activity, in the form of running at least 20miles/wk. and training for at least one race per year, did not mitigate the characteristic age-related differences in gait kinetics. Our findings may indicate that age-related differences in lower-extremity gait kinetics are a normal consequence of natural aging.

Gene expressions in cerebral palsy subjects reveal structural and functional changes in the gastrocnemius muscle that are closely associated with passive muscle stiffness.

Cerebral palsy (CP) is a non-progressive motor disorder that affects posture and gait due to contracture development. The purpose of this study is to analyze a possible relation between muscle stiffness and gene expression levels in muscle tissue of children with CP. Next-generation sequencing (NGS) of gene transcripts was carried out in muscle biopsies from gastrocnemius muscle (n=13 children with CP and n=13 typical developed (TD) children). Passive stiffness of the ankle plantarflexors was measured. Structural changes of the basement membranes and the sarcomere length were measured. Twelve pre-defined gene target sub-categories of muscle function, structure and metabolism showed significant differences between muscle tissue of CP and TD children. Passive stiffness was significantly correlated to gene expression levels of HSPG2 (p=0.02; R2=0.67), PRELP (p=0.002; R2=0.84), RYR3 (p=0.04; R2=0.66), C COL5A3 (p=0.0007; R2=0.88), ASPH (p=0.002; R2=0.82) and COL4A6 (p=0.03; R2=0.97). Morphological differences in the basement membrane were observed between children with CP and TD children. The sarcomere length was significantly increased in children with CP when compared with TD (p=0.04). These findings show that gene targets in the categories: calcium handling, basement membrane and collagens, were significantly correlated to passive muscle stiffness. A Reactome pathway analysis showed that pathways involved in DNA repair, ECM proteoglycans and ion homeostasis were amongst the most upregulated pathways in CP, while pathways involved in collagen fibril crosslinking, collagen fibril assembly and collagen turnover were amongst the most downregulated pathways when compared with TD children. These results underline that contracture formation and motor impairment in CP is an interplay between multiple factors.

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

Partial foot amputation is often associated with decreased mobility and function. Recent advances in custom carbon-fiber dynamic ankle-foot orthoses (CDOs) have improved gait, pain, and function following musculoskeletal trauma and can benefit individuals with partial foot amputation. However, limited information is available related to CDO use outside the military. The purpose of this case report is to describe the course of care and outcomes of a civilian provided with CDOs after bilateral transmetatarsal amputation. A 72-year-old man had a blood-borne bacterial infection (septicemia) of unknown origin at 68years of age, developed limb-threatening necrosis of the hands and feet, and received bilateral transmetatarsal amputations with skin grafting. The patient initially used foam toe fillers and cushioned shoes but was functionally limited and experienced recurrent ulceration. He was fitted with bilateral CDOs 39months after amputation and completed device-specific training with a physical therapist. After 1week with the CDOs, ankle range of motion during gait was reduced, but greater than 40% increases were observed in bilateral ankle plantarflexor moments and ankle plantarflexion push-off power compared with the toe fillers. With additional therapist-directed training focused on gait and activity performance, ankle plantarflexor moments and plantarflexion push-off power further increased when compared with results after 1week of CDO use. The patient reported marked improvement in quality of life with the CDOs due to improved walking ability on level and uneven terrain, marked improvement in confidence, and reduced pain. This case reflects the lessons learned and outcomes of a civilian using bilateral CDOs after bilateral transmetatarsal amputation and with poor skin quality. The results from this case study suggest that carbon-fiber CDOs and focused training by a physical therapist can result in improved gait biomechanics, mobility, and quality of life.

Is Ankle Plantar Flexor Strength Associated With Balance and Walking Speed in Healthy People? A Systematic Review and Meta-Analysis.

The purpose of this study was to investigate the association between ankle plantar flexor muscle (PF) strength and balance and walking speed in healthy adults. Four databases (Ovid MEDLINE, Ovid EMBASE, CINAHL Plus, and SPORTDiscus) were searched from inception to December 2019. Studies with any design were included if the association between PF strength and balance and walking speed was investigated among healthy adults. Articles were screened for eligibility independently by 2 reviewers. Study characteristics and Pearson r values derived from the association between PF strength and balance and walking speed were extracted. Thirty-four studies were eligible. The main group of interest in the studies was older adults. Pearson r values were transformed to rz values using Fisher z-transformation. Meta-analysis of rz values was conducted and then back-transformed to r. In older adults, PF maximal isometric strength had a positive weak association with static balance (r=0.20; 95% CI=0.08-0.32), a positive moderate association with dynamic reactive balance (r=0.42; 95% CI=0.32-0.57) and proactive balance (r=0.55; 95% CI=0.18-1.06), and a positive weak association with preferred walking speed (r=0.29; 95% CI=0.19-0.41) and maximum walking speed (r=0.34; 95% CI=0.06-0.63). In younger adults, there was a moderate association between early-phase PF rate of torque development and reactive balance (0.42<r<0.52). PF strength appears to be moderately associated with dynamic reactive and proactive balance and weakly associated with static balance and walking speed. This finding highlights the potential role of PF strength in dynamic reactive and proactive balance. This meta-analysis showed that ankle PF strength might be important for challenging dynamic balance tasks.

People with mild PD have impaired force production in all lower limb muscle groups: A cross-sectional study.

Power is reduced in people with Parkinson's disease as a consequence of bradykinesia, but it is not clear whether reduced power is also due to a deficit in force production. The aim of this study was to quantify force production in all major lower limb muscle groups in people with PD during the "on" phase after medication, compared with aged-matched neurologically normal control participants. Design: A cross-sectional study was undertaken. Thirty ambulatory people with PD and 24 neurologically normal controls. Isometric force production of the hip flexors and extensors, hip adductors and abductors, hip internal rotators and external rotators, knee flexors and extensors, ankle dorsiflexors and plantarflexors, ankle invertors and evertors using hand-held dynamometry. There was a significant deficit in force production in participants with PD in all lower limb muscle groups tested, compared with control participants. On average, force production of participants with PD was 78% (range 67%-87%) of control participants, despite participants with PD regularly participating in exercise, being measured during their "on" phase after medication and having normal walking ability. The most severely affected muscle groups were the hip adductors (67%) and ankle plantarflexors (68%). People with PD have a significant loss of force production in all lower limb muscle groups compared with age-matched neurologically-normal controls. Clinicians should regularly assess the strength of all lower limb muscle groups, regardless of participation in physical activity, responsiveness to levodopa medication and walking ability.