Abstract
The purposes of this study were to measure duration between burst of activity in leg muscles and heel contact of the affected legs during walking in patients with hip diseases, and to compare activity time with that of normal subjects. Subjects involved in this investigation were 10 patients with osteoarthritics of the hip (all female, mean age 42.5±8.3years, range 29 to 57), and 10 normal persons (all female, mean age 37.6±13.1 years, range 19 to 67). The foot switch signals, electromyography (EMG) activity of the gluteus medius (GM-EMG) and rectus femoris (RF-EMG) were recorded simultaneously during walking. Duration change from heel strike to burst of activity of GM-EMG (DAGM) and RF-EMG (DARF) were measured in the stance phase. The DAGM and DARF of the patients were slower than those of normal subjects (t=4.03, p<.001; t=2.39, p<.05). Significant correlation was found between DAGM and DARF in normal subjects (r=.72, p<.05), but no significant correlation was found between DAGM and DARF in normal subjects (r=.72, p<.05), but no significant correlation was found between DAGM and DARF in the patients (r=.213). These results suggest that pre-activity of DAGM in patients is more delayed than that of normal people, and the muscle does not coordinate with each other during walking cycle in the patients with hip diseases.
