Effect of Ankle Weights on EMG Activity of the Semitendinosus and Knee Stability During Walking by Community-Dwelling Elderly

[Purpose] To examine the effect of ankle weights on the activation of the semitendinosus and the anterior instability of the knee. [Subjects] Thirty-nine healthy elderly women. [Methods] Subjects randomly performed three load conditions (0, 1.5, 2.5 kg). We calculated the mean integrated EMG amplitude (iEMG, μV) of the semitendinosus during one gait cycle and the loading response. The anterior instability of the knee was calculated as the anterior displacement of the tibia in response to the femur. [Results] The amount of anterior instability showed no significant difference between the 2.5 kg condition and the 0 kg condition, and was significantly smaller in both these conditions than in the 1.5 kg condition. The iEMG amplitude of the 2.5 kg condition was significantly higher than the other conditions, although the iEMG of the 1.5 kg condition was not significantly different from the no load condition. [Conclusion] Wearing 2.5 kg would be better for strengthening the semitendinosus than wearing 1.5 kg.