Reducing Fall Risk With NMES

Falls are a leading cause of disability in older adults. Decreased lower extremity muscle mass and strength contribute to balance and mobility limitations. More recent work also suggests that in addition to the traditional targets of muscle mass of the thigh and leg muscles, dysfunction of the hip abductors may contribute to balance and mobility limitations resulting in increased fall risk. Older adults with impaired hip abductor muscles demonstrate increased amounts of intramuscular fat (IMAT) in and around the muscles, decreased hip abductor strength, lower balance scores, increased gait variability (a predictor of future falls), and poor stepping mechanics when recovering from a balance perturbation. Increased IMAT and muscle dysfunction of the hip abductors may contribute to poor hip abductor muscle recruitment and make changing these muscle during a traditional intervention difficult. Neuromuscular electrical stimulation (NMES) is one method to improve muscle mass, strength and quality in older adults, but has not traditionally been used on the hip abductors. The investigator's central hypothesis is that the addition of NMES applied to the primary hip abductors during a multimodality balance intervention (MMBI) will result in greater reduction in fall risk and larger improvements in muscle and mobility function than MMBI alone. The investigators will test this hypothesis with the following specific aims: Aim 1: To determine the 3-month effects of a multimodality balance intervention with and without NMES on fall risk. Aim 2: To examine the 3-month effects of a multimodality balance intervention with and without NMES on functional outcomes including muscle function and composition. Aim 3: To evaluate the retention of balance, muscle changes and reduced falls after a multimodality balance intervention with and without NMES