Rapid repetitive passive movement promotes knee proprioception in the elderly

Joint proprioception plays an important role in the generation of coordinated movements, maintenance of normal body posture, body conditioning, motor learning, and relearning. Previous studies have demonstrated that proprioceptive function of the elderly can be enhanced via specific exercises; however, not all of the elderly can actively and safely participate in physical activities. The purpose of this study was to evaluate the effects of rapid repetitive passive movement in an average velocity of 90A degrees/s on knee proprioception in the elderly. A repeated-measure design was employed. Two age groups (12 young/12 elderly) were intervened with repetitive passive movements of 60 repetitions to the knee joint via two machines (isokinetic dynamometer/self-designed machine) in separate days. Changes in proprioception were evaluated via joint active repositioning and kinesthesia, both before and after the intervention. The results revealed that all subjects demonstrated good test-retest reliabilities on proprioceptive measurements. For the active repositioning and kinesthesia, significant statistical main effects were found for group and time, but not for machine. No statistical interactions were revealed. Despite of age-related proprioceptive declines, elderly subjects could benefit from rapid repetitive passive movements. This indicates that repetitive passive movement may be an alternative to physical activity for those who are home-bound, in a sedentary lifestyle, or with other health conditions that may limit their abilities to actively maintain or strengthen joint proprioception.