Plantar Flexor Strength Training With Home-Based Neuromuscular Electrical Stimulation Improves Limits of Postural Stability in Older Adults

Background: The study aimed to determine whether improved muscle strength after 12 weeks of neuromuscular electrical stimulation (NMES) of plantar and dorsiflexors could result in better limits of stability in older adults. Methods: Twenty-seven participants were divided into a control group and a neuromuscular home-based training group. The training group performed a 3-month long NMES training of both plantar and dorsiflexors. Ankle flexor strength and limits of stability were measured. A mediation analysis was conducted to determine whether the NMES effect on the limits of stability was mediated by increased strength. Results: The NMES training increased plantar flexor strength (+47%; beta = 0.217, P =.02), and this increase predicted the anterior limits of stability improvement (+27%; beta = 0.527, P =.02). The effect of the NMES on the limits of stability was fully mediated by the plantar flexor strength increase (indirect effect: beta = 0.1146; 95% confidence interval, 0.020-0.240). Conclusion: It seems that NMES improves the limits of stability through its positive effect on muscle strength. NMES may be utilized in fallprevention programs.