- バイオメカニズム (ISSN:13487116)
- vol.15, pp.235-242, 2000-06-15 (Released:2016-12-05)
Purpose Exercise of patients was carried out to maintain and improve their body functions. The load on the hip joint during exercise was analyzed using the integrated EMG and force measurement of agonist and antagonist muscles. Method Experiment 1: The relationship between the integrated EMG and the muscle force of hip abduction was examined to identify their linearity up to 100% MVC using a Cybex 6000. Twelve lower extremities of six healthy males were used. Experiment 2: The load on the hip joint was estimated through this experiment, using twenty lower extremities of ten healthy males. Exercises such as straight leg raising (SLR), hip abduction, and knee extension were performed. The integrated EMG at 100% MVC and the muscle force of agonist and antagonist were measured. Then the integrated EMGs of agonist and antagonist were measured to determine the muscle force in proportion to the force at 100% MVC. Mathematical models were used to analyze the load on the hip joint in each exercise. Results Experiment 1: The integrated EMG and the muscle force of the hip abduction showed a strong linearity up to 100% MVC. Experiment 2: In SLR, the resultant force on the hip joint was 908 N and 1.4 times body weight at 10 degrees hip flexion. It was 765 N and 1.2 times body weight at 20 degrees, and 657 N and equal to body weight at 30 degrees. In hip abduction in the lateral position, it was 1.8 times body weight at 10 degrees hip abduction, and it decreased with increasing hip abduction. In knee extension with sitting, it was 127 N and 0.2 times body weight at a 60-degree knee flexion angle, and it increased gradually with knee extension. Conclusion The analyzed values showed good agreement with those from sensorized prostheses. The proposed method in this study was considered appropriate for evaluating the load on the hip joint during exercise. In SLR, the load was 1.4 times body weight, which was unexpected. Our approach will be applicable to other exercises in a rehabilitation protocol.