Reducing Fall Risk With NMES

Overview

Falls are dangerous leading to injuries, hospital admissions and even death. Fall prevention is a priority but effective programs only reduce falls by 30%. Weak hip muscles may be one reasons individuals experience a loss of balance. However individuals who have weak hip muscles may be unable to exercise at sufficient intensities to improve their hip muscle strength. The purpose of this study is to utilize a common physical therapy method, neuromuscular electrical stimulation (NMES), on the hip muscles to improve hip muscle strength and improve balance. The new program focuses on using NMES during a resistance training program along with exercise to improve standing balance, walking and stepping over objects. This study will test the additive effect of NMES applied to the hip muscles during a balance and strengthening program to improve balance and mobility, and ultimately reduce the risk of falls in older Veterans at high risk for falls.

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