The electromyographic (EMG) gait patterns of both lower limbs in 12 hemiparetic patients were studied during the early and late recovery periods. The linear envelopes of surface EMG were ensemble averaged to represent performance. The patients' stride parameters and EMG envelopes were compared to those of normal individuals measured at very-slow walking speeds. Both limbs could have normal or a...

Stiffperson syndrome (SPS) is manifested by increased tone of the trunk muscles that gradually spreads to the limbs. The mechanism underlying this muscle hypertonia involves derangement of the inhibitory action of gaminobutyric acid (GABA) at cortical and spinal levels with subsequent continuous motor unit activity. A cocontraction mechanism with a board-like abdomen and painful lumbar hyperlor...

This study investigated the cocontraction of eight trunk muscles during the application of asymmetric loads to the torso. External moments of 10, 20, 30, 40, and 50 Nm were applied to the torso via a harness system. The direction of the applied moment was varied by 30 degrees increments to the subjects' right side between the sagittally symmetric orientations front and rear. Electromyographic (...

The marine mollusc Aplysia californica provides an excellent preparation with which to examine the development of the neuronal control of behavior for 2 reasons: first, adult Aplysia exhibit a variety of behaviors that are well understood in cellular terms; and second, the development of Aplysia from embryo to adult has been studied in considerable detail. Among the best understood behaviors in...