Effects of Vibration Stimuli on the Knee Joint Reposition Error of Elderly Women

[Purpose] This study investigated which frequency levels of vibration affect the knee joint reposition error of elderly women. [Subjects] The subjects of this study were 13 healthy elderly women who had no orthopedic or neurological problems. [Methods] Oscillators were attached to the e bellies of the tibialis anterior, gastrocnemius, biceps femoris, and rectus femoris muscles on the dominant-side lower limbs of the subjects. In order to identify the effects of vibration stimuli on elderly women's knee joint position sense, knee joint reposition error tests were conducted under randomly selected different conditions (open kinetic chain or closed kinetic chain) and frequencies of vibration (control condition, placebo condition, 10 Hz, 60 Hz, and 120 Hz). [Results] In the open kinetic chain, the knee joint reposition errors were significantly different among conditions (control, placebo, 10 Hz, 60 Hz, and 120 Hz). The knee joint reposition error of 60 Hz vibration was the smallest, but that of 120 Hz was higher than those of the other conditions. In the closed kinetic chain, there were no significant differences among the conditions. [Conclusion] Vibration of 60 Hz is an appropriate frequency for decreasing knee joint reposition error, and for stimulating the proprioceptive sense of the human body. Further studies will be required of the effects of vibration stimulation in future.