Age-related changes in muscle function which affect hip extension moment generation during sit-to-stand motion

Abstract

[Purpose] The purpose of this study was to examine the relationship between muscle activity and joint moment and age-related changes during sit-to-stand motion. [Subjects] Both young healthy women (n=16) and elderly healthy women (n=16) participated in this study. [Method] Lower limb joint moments were obtained using a three-dimensional motion analysis system and force plates. The muscle activities were recorded using surface electromyography. We analyzed the hip and knee moments and integrated electromyograms (IEMG). [Result] Some elderly adults demonstrated a greater peak knee extension moment than the peak hip extension moment, and the IEMG of the gluteus maximus and gluteus medius were both significantly higher than those of the young group. [Conclusion] Some elderly adults tended to show a decrease in their hip extension moment, and the muscle activities of the gluteus maximus and gluteus medius were observed to continuously increase during sit-to-stand motion. © 2013 by the Society of Physical Therapy Science.