Relationship between lower extremity isometric muscle strength and standing balance in patients with multiple sclerosis

BACKGROUND: Muscle strength and standing balance decrease in patients with Multiple Sclerosis (MS). OBJECTIVE: The aim of the present study was to investigate the relationship between the lower extremity isometric muscle strength and standing balance in patients with MS. METHODS: Forty-seven patients with MS and 10 healthy volunteers were included. Neurological disability level was assessed using Expanded Disability Status Scale (EDSS). Isometric strength of seven lower extremity muscles (hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor) was assessed using hand-held dynamometer. Duration of static one-leg standing balance was measured using digital chronometer. RESULTS: Hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor isometric muscle strength, and duration of one-leg standing balance were decreased in patients with MS when compared with controls (p < 0.05). All assessed lower extremity isometric muscle strength and EDSS level were related duration of one-leg standing balance in patients with MS. All assessed lower extremity isometric muscle strength (except ankle dorsal flexor) was related with EDSS. CONCLUSIONS: Hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor isometric muscle strength decreases in ambulatory MS patients. Lower extremity muscle weakness and neurological disability level are related with imbalance in MS population. Hip and knee region muscles weakness increases the neurological disability level. For better balance and decreasing neurological disability level whole lower extremity muscle strengthening should be included in rehabilitation programs.