Abstract
The push-up motion is one of the essential activities for patients with spinal cord injury (SCI). The push-up motion is the raising of bodies up from the sitting position on the bed, the floor or the wheelchair. Physical therapists should train the patients to improve 3 factors, that is the skill, the power and the maintenance of the power. We made push-up motion measurement system that measure three dimensional floor reaction forces of hands during push-ups, and measured this activity according to this system in 27 SCI subjects. We calculated the torque of shoulder joints to evaluate the power of push-ups, and analyzed the force data to evaluate the skill of push-ups in order to apply to rehabilitation medicine. From careful observation, we recognize 2 manners of the push-up motion in SCI. These are the passive manner and the active one. The hip joints of some SCI subjects move backwards and they elevate their hips as highly as possible. We call this manner the active manner. As the results of this study, the following conclusions were obtained. (1) The torque of the shoulder joints is a very important power factor of the push-up motion. We calculated this value by using very simple mechanical model. The shoulder torque is high in the subjects whose push-ups show the active manner. This torque can be a parameter to evaluate the power of push-ups. (2) We compare and analyze three dimensional floor reaction among each subject. Then we found that the pattern of anteroposterior force Fx was quite different among the subjects. The patterns of Fx could be classified into 4 types. The Fx distinguishes one of these types (Type C) when the subjects performed push-up in the active manner. The Fx pattern can be a parameter to evaluate the skill of push-ups.
