SOME OBSERVATIONS ON THE TRANSVERSE ROTATIONS OF THE HUMAN TRUNK DURING LOCOMOTION a b

The transverse rotations of the human pelvis and shoulder girdle duiing walking were studied and compared in 10 young men and 10 young women. Three sets of measurements were made for each subject : transverse rotation of the pelvis, transverse rotation of the shoulder girdle, and simultaneous transverse rotations of the pelvis and the shoulder girdle . All measurements were made while the subjects walked on a level treadmill at each of three different speeds (2 .93 km./hr ., 4 .39 km./hr., and 5.86 km./hr.) . A broad leather pelvic belt and two shoulder clamps connected by a crossbar were used. A linear variable differential transformer in a special mount which converted angular motion to linear motion was used to measure the angular displacements . Recordings were made with a Tektronix storage oscilloscope at sweep speeds of 0 .2 sec./cm., 0 .5 sec./cm., and 1 .0 sec ./cm. For several trial runs, a specially developed goniometer was used to measure the rotations. In general, no great differences between men and women were found in any of the average amounts of rotation . Nearly all the highest individual values were measured in men and the lowest in women . Rotations of the pelvis increased in amount and became more uniform in pattern as speed increased, whereas rotations of the shoulder girdle dea This work was supported in part by contract V1005M—2075 from the Veterans Administration and in part by Training Grant 185—T from the Vocational Rehabilitation Administration, now part of the Social and Rehabilitation Service, Department of Health, Education, and Welfare. b Also published as : Chapman, M . W., and Kurokawa, K . M . : Some Observations on the Transverse Rotations of the Human Trunk During Locomotion . Biomechanics Laboratory, University of California, San Francisco and Berkeley, Technical Memorandum. San Francisco, The Laboratory, May 1968, 29 pp. o Assistant Resident, Department of Orthopaedic Surgery, University of California School of Medicine, San Francisco, Calif . 94122. Chapman and Kurokawa : Transverse Rotations During Locomotion creased at higher speeds . When the subjects walked at 4 .39 km./hr ., the sum of separately measured rotations of the pelvis and the shoulder girdle exceeded, in all but two cases, the amounts of directly measured counterrotations of the pelvis and the shoulder girdle . This finding suggests that, at this speed of walking, the rotations of these two segments of the body are not exactly 180 deg . out of phase.