Interactions between posture and locomotion: motor patterns in humans walking with bent posture versus erect posture

posture and locomotion: motor patterns in humans walking with bent posture versus erect posture. J. Neurophysiol. 83: 288–300, 2000. Human erect locomotion is unique among living primates. Evolution selected specific biomechanical features that make human locomotion mechanically efficient. These features are matched by the motor patterns generated in the CNS. What happens when humans walk with bent postures? Are normal motor patterns of erect locomotion main-tained or completely reorganized? Five healthy volunteers walked straight and forward at different speeds in three different postures (regular, knee-flexed, and knee- and trunk-flexed) while their motion, ground reaction forces, and electromyographic (EMG) activity were recorded. The three postures imply large differences in the position of the center of body mass relative to the body segments. The elevation angles of the trunk, pelvis, and lower limb segments relative to the vertical in the sagittal plane, the ground reaction forces and th