Enhanced neural drive after maximal strength training in multiple sclerosis patients

Multiple sclerosis (MS) patients suffer from impaired muscle activation and lower limb strength. Strength training enhances muscle activation and muscle strength, but neural adaptations to strength training remain unexplored in MS patients. The hypothesis was that maximal strength training (MST) using high loads and few repetitions would improve central neural drive and thus strength capacity of MS patients. 14 MS patients staying at a national MS rehabilitation center were randomly assigned to a MST group or a control group (CG). Both groups received "today's treatment". In addition, the MST group trained 4 x 4 repetitions of unilateral dynamic leg press and plantar flexion 5 days a week for 3 weeks. Neural adaptations of the soleus muscle were assessed by surface electromyography (EMG) activity, and by superimposed H-reflexes and V-waves obtained during maximum voluntary isometric plantar flexor contractions (MVCs). H-reflexes and V-waves were normalized by the M-wave (H(SUP)/M(SUP), V/M(SUP), respectively). In the MST group, MVC increased by 20 +/- 9% (P < 0.05). Soleus EMG activity and V/M(SUP) ratio increased by 40 and 55%, respectively, in the MST group compared to the CG (P