Errors in the ankle plantarflexor force production are related to the gait deficits of individuals with multiple sclerosis

Davies, Brenda L.; Hoffman, Rashelle M.; Healey, Kathleen; Zabad, Rana; Kurz, Max J.

doi:10.1016/j.humov.2016.11.008

Cited by 20 publications

(14 citation statements)

References 47 publications

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“…In addition, biomechanical gait deficits (i.e., reduced push-off and toe clearance in swing) were found to be consistent with impairments in activation and coordination of these distal synergies. This corroborated findings of others that have identified the reduction of (i) propulsion and (ii) foot-ground clearance during swing to be among the most disabling deficits in gait of PwMS ( 25 , 26 ).…”

Section: Introductionsupporting

confidence: 90%

Improved Gait of Persons With Multiple Sclerosis After Rehabilitation: Effects on Lower Limb Muscle Synergies, Push-Off, and Toe-Clearance

et al. 2020

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Introduction: Persons with MS (PwMS) have markedly reduced push-off and toe-clearance during gait compared to healthy subjects (HS). These deficits may result from alterations in neuromotor control at the ankle. To optimize rehabilitation interventions for PwMS, a crucial step is to evaluate if and how altered neuromotor control, as represented by muscle synergies, improves with rehabilitation. In this study we investigated changes in ankle motor control and associated biomechanical parameters during gait in PwMS, occurring with increase in speed after gait rehabilitation. Methods: 3D motion and EMG data were collected while 11 PwMS (age 50.3 + 11.1; EDSS 5.2 + 1.2) walked overground at self-selected speed before (T0) and after 20 sessions (T1) of intensive treadmill training. Muscle synergies were extracted using non-negative matrix factorization. Gait parameters were computed according to the LAMB protocol. Pearson's correlation coefficient was used to evaluate the similarity of motor modules between PwMS and HS. To assess differences in distal module activations representing neuromotor control at the ankle [Forward Propulsion (FPM) and Ground Clearance modules (GCM)], each module's activation timing was integrated over 100% of the gait cycle and the activation percentage index (API) was computed in six phases. Ten age matched HS provided two separate speed-matched normative datasets for T0 and T1. For speed independent comparison for the PwMs Z scores were calculated for all their gait variables. Results: In PwMS velocity increased significantly from T0 to T1 (0.74–0.90 m/s, p < 0.05). The activation profiles (API) of FPM and GCM of PwMS improved in pre-swing ( p < 0.05): FPM (Mean [95% CI] [%]: T0: 12.5 [5.7–19.3] vs. T1: 9.0 [2.7–15.3]); GCM (T0: 26.7 [18.2–35.3] vs. T1: 24.5 [18.2–30.7]). This was associated with an increase in toe clearance (80.3 to 103.6 mm, p < 0.05) and a higher ankle power peak in pre-swing (1.53–1.93 W/kg, p < 0.05). Conclusion: Increased gait speed of PwMS after intensive gait training was consistent with improvements in spatio-temporal gait parameters. The most important finding of this study was the re-organization of distal leg modules related to neurophysiological changes induced by rehabilitation. This was associated with an improved ankle performance.

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Section: Introductionsupporting

confidence: 90%

Improved Gait of Persons With Multiple Sclerosis After Rehabilitation: Effects on Lower Limb Muscle Synergies, Push-Off, and Toe-Clearance

et al. 2020

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“…Human posture control and motion require sufficient coordination of central nervous and musculoskeletal systems. In the musculoskeletal system, the ankle plantar-flexors generate necessary force for foot propulsion during walking [1] and running [2], as well as maintaining the static and dynamic balance control [3] in human. The function of plantar-flexor has been suggested as one strong indicator of gait performance [4].…”

Section: Introductionmentioning

confidence: 99%

“…The function of plantar-flexor has been suggested as one strong indicator of gait performance [4]. Weakness [1] and contracture [5] of plantar-flexor tend to adversely affected balance and gait, leading to higher risk of falls [6].…”

Section: Introductionmentioning

confidence: 99%

Towards Wearable Comprehensive Capture and Analysis of Skeletal Muscle Activity during Human Locomotion

Zong-Hao

Ling

Shea

et al. 2019

Sensors

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Background: Motion capture and analyzing systems are essential for understanding locomotion. However, the existing devices are too cumbersome and can be used indoors only. A newly-developed wearable motion capture and measurement system with multiple sensors and ultrasound imaging was introduced in this study. Methods: In ten healthy participants, the changes in muscle area and activity of gastrocnemius, plantarflexion and dorsiflexion of right leg during walking were evaluated by the developed system and the Vicon system. The existence of significant changes in a gait cycle, comparison of the ankle kinetic data captured by the developed system and the Vicon system, and test-retest reliability (evaluated by the intraclass correlation coefficient, ICC) in each channel’s data captured by the developed system were examined. Results: Moderate to good test-retest reliability of various channels of the developed system (0.512 ≤ ICC ≤ 0.988, p < 0.05), significantly high correlation between the developed system and Vicon system in ankle joint angles (0.638R ≤ 0.707, p < 0.05), and significant changes in muscle activity of gastrocnemius during a gait cycle (p < 0.05) were found. Conclusion: A newly developed wearable motion capture and measurement system with ultrasound imaging that can accurately capture the motion of one leg was evaluated in this study, which paves the way towards real-time comprehensive evaluation of muscles and joint motions during different activities in both indoor and outdoor environments.

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“…For instance, a common manifestation of MS is di culty clearing the foot during the swing phase of gait, which is often attributed to dorsi exion and eversion weakness in the ankle. AFOs are frequently prescribed in this situation (13,14).…”

Section: Introductionmentioning

confidence: 99%

Biomechanical Analysis of an Unpowered Hip Flexion Orthosis on Individuals With and Without Multiple Sclerosis

Neuman¹,

Shearin

McCain

et al. 2020

Preprint

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BackgroundGait impairment is a common complication of multiple sclerosis (MS). Gait limitations such as limited hip flexion, foot drop, and knee hyperextension often require external devices like crutches, canes, and orthoses. The effects of mobility-assistive technologies (MATs) prescribed to people with MS are not well understood, and current devices do not cater to the specific needs of these individuals. To address this, a passive unilateral hip flexion-assisting orthosis (HFO) was developed that uses resistance bands spanning the hip joint to redirect energy in the gait cycle. The purpose of this study was to investigate the short-term effects of the HFO on gait mechanics and muscle activation for people with and without MS.MethodsFive healthy subjects and five subjects with MS walked for minute-long sessions with the device using three different levels of band stiffness. We analyzed peak hip flexion and extension angles, lower limb joint work, and muscle activity in eight muscles on the lower limbs and trunk. Single-subjects analysis was used due to inter-subject variability.ResultsFor subjects with MS, the HFO caused an increase in peak hip flexion angle and a decrease in peak hip extension angle. Healthy subjects showed less pronounced kinematic changes when using the device. Power generated at the hip was increased in most subjects with the HFO. Muscle activity showed inconsistent results, but several subjects showed increases in hip extensor and trunk muscle activity.ConclusionsThis exploratory study showed that the HFO was well-tolerated by healthy subjects and subjects with MS, and that it promoted more normative kinematics at the hip for those with MS. Future studies with longer exposure to the HFO and personalized assistance parameters are needed to understand the efficacy of the HFO for mobility assistance and rehabilitation for people with MS.

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Errors in the ankle plantarflexor force production are related to the gait deficits of individuals with multiple sclerosis

Abstract: Altogether these results imply that errors in the ankle plantarflexion force production may be a limiting factor in the mobility of individuals with MS.

Cited by 20 publications

References 47 publications

Improved Gait of Persons With Multiple Sclerosis After Rehabilitation: Effects on Lower Limb Muscle Synergies, Push-Off, and Toe-Clearance

Improved Gait of Persons With Multiple Sclerosis After Rehabilitation: Effects on Lower Limb Muscle Synergies, Push-Off, and Toe-Clearance

Towards Wearable Comprehensive Capture and Analysis of Skeletal Muscle Activity during Human Locomotion

Biomechanical Analysis of an Unpowered Hip Flexion Orthosis on Individuals With and Without Multiple Sclerosis

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