Are modular activations altered in lower limb muscles of persons with Multiple Sclerosis during walking? Evidence from muscle synergies and biomechanical analysis

Frontiers in Human Neuroscience

Alessandro Crippa¹  Elisa Gervasoni¹  Marco Rovaris¹  Tiziana Lencioni¹  Johanna Jonsdottir¹  Maurizio Ferrarin¹  Davide Cattaneo¹  Emilio Bizzi² 

[1] IRCCS Fondazione Don Carlo Gnocchi ONLUS;Massachusetts Institute of Technology;

关键词: Gait;    Multiple Sclerosis;    EMG;    Muscle Synergy;    lower limb;   

DOI  :  10.3389/fnhum.2016.00620

来源: DOAJ

【 摘 要 】

BackgroundPersons with Multiple Sclerosis frequently have gait deficits that lead to diminished activities of daily living. Identification of motoneuron activity patterns may elucidate new insight into impaired locomotor coordination and underlying neural systems. The aim of the present study was to investigate muscle synergies, identified by motor modules and their activation profiles, in persons with Multiple Sclerosis (PwMS) during walking compared to those of healthy subjects (HS), as well as, exploring relationship of muscle synergies with walking ability of PwMS.MethodsSeventeen PwMS walked at their natural speed while 12 HS walked at slower than their natural speeds in order to provide normative gait values at matched speeds (spatio-temporal, kinematic and kinetic parameters and electromyography signals). Non-negative matrix factorization was used to identify muscle synergies from eight muscles. Pearson's correlation coefficient was used to evaluate the similarity of motor modules between PwMS and HS. To assess differences in module activations, each module's activation timing was integrated over 100% of gait cycle and the activation percentage was computed in six phases.ResultsFifty-nine% of PwMS and 58% of HS had 4 modules while the remaining of both populations had 3 modules. Module 2 (related to soleus, medial and lateral gastrocnemiusprimarily involved in mid and terminal stance) and Module 3 (related to tibialis anterior and rectus femorisprimarily involved in early stance, and early and late swing) were comparable across all subjects regardless of synergies number. PwMS had shorter stride length, longer double support phase and push off deficit with respect to HS (p<0.05). The alterations of activation timing profiles of specific modulesin PwMS were associated with their walking deficits (e.g. the reduction of Module 2 activation percentage index in terminal stance, PwMS 35.55±13.23 vs HS 50.51±9.13% p<0.05, and the push offdeficit, PwMS 0.181±0.136 vs HS 0.291±0.062 W/Kg p<0.05). ConclusionDuring gait PwMS have synergies numbers similar to healthy persons. Their neurological deficit alters modular control through modifications of the timing activation profiles rather than module composition. These changes were associated with their main walking impairment, muscle weakness and prolonged double support.

【 授权许可】

Unknown