Does neuromuscular electrical stimulation training of the lower limb have functional effects on the elderly?: A systematic review

The lower limb muscle functions of the elderly are known to be preferentially altered by ageing. Traditional training effectively counteracts some of these functional declines but is not always accessible due to its cost and to the accessibility of the training centers and to the incapacities of some seniors to practice some exercises. Neuromuscular electrical stimulation (NMES) could provide an interesting alternative muscle training technique because it is inexpensive and transportable. The aim of this systematic review was to summarize the current evidence on the effect of the use of lower limb NMES as a training technique for healthy elderly rehabilitation. Electronic databases were searched for trials occurring between 1971 (first occurrence of NMES training) and November 2016. Ten published articles were retrieved. Training programs either used NMES alone, or NMES associated with voluntary muscle contraction (NMES+). They either targeted calves or thigh muscles and their training length and intensity were heterogeneous but all studies noted positive effects of NMES on the elderly's functional status. Indeed, NMES efficiently improved functional and molecular muscle physiology, and, depending on the studies, could lead to better gait and balance performances especially among less active elderly. Given the association between gait, balance and the risk of falls among the elderly, future research should focus on the efficiency of NMES to reduce the high fall rate among this population.