The purpose of this study is to examine the movement characteristics of the upper limb supported floor scooting movement in bilateral lower extremity amputees. The subject was one adult male who had amputee bilateral lower extremity. The measurements were examined using 3D motion analysis and ground reaction force and electromyography. The following results were obtained. The proportion of flexion phase was significantly higher in spine flexion posture than in spine extension posture （p<0.05）. The maximum value of shoulder joint motion on the sagittal plane during the extension phase was significantly greater in the spinal extension posture than in the spinal flexion posture （p<0.05）. From floor reaction force data, the spinal flexion posture was the trend to push the upper extremities more strongly during movement than the spinal extension posture in the flexion phase, the rectus abdominis muscle activity was intentionally greater, and the biceps brachii muscle activity was intentionally lower in the spine extension posture than in the spine flexion posture （p<0.05）. Similar to previous studies, it was suggested that the spine extension posture is an efficient movement posture, and the spine flexion posture is a movement posture that loads the muscles of the upper limb girdle. However, since the weight of the lower limbs and the contact area with the floor were small due to the amputation of both lower legs, the spinal flexion posture was a posture that promoted speed and distance in one movement compared to the spinal extension posture.
This study evaluated the displacement of the body’s center of gravity during running jumps by categorizing it into elements,namely: “hinge moment” and “telescoping of the lower limbs” using a polar coordinate system. We examined whether hinge moment and telescoping of the lower limbs contribute to the jump height in the running jump of basketball players and whether the jump motions are related to these elements. A total of 21 college basketball players were recruited. Running jumps were measured using a high-speed camera. The three-dimensional coordinates of the body’s center of gravity were obtained, and its upward displacement due to the hinge moment and the telescoping of the lower limbs was determined. The results revealed the following:
（１） The factors contributing to the jumping height during the running jump were the maximum upward acceleration, owing to the hinge moment immediately after ground contact, and the maximum upward velocity, because of the telescoping of the lower limbs in the second half of the take-off.
（２） Jumping motions related to hinge moment included more plantar flexion of the ankle joint at heel contact and quicker plantar flexion after heel contact. Moreover，there should be no sudden extension of the hip joint immediately after heel contact. The body tilt at heel contact should be approximately 45 degrees.
（３） Jumping motions associated with telescoping of the lower limbs comprised the horizontal velocity of the body’s center of gravity at heel contact and the maximum dorsiflexion angle of the ankle joint during the latter half of the take-off.