MUSCLE TONE AROUND THE HUMAN KNEE IN PARAPLEGIA
- 12 November 1989
- journal article
- research article
- Published by Wiley in Quarterly Journal of Experimental Physiology
- Vol. 74 (6) , 897-905
- https://doi.org/10.1113/expphysiol.1989.sp003360
Abstract
The thigh muscle tone of non‐injured subjects and complete injury paraplegics has been investigated using torques, generated by a printed motor, to move the knee. The dynamic measure of resonant frequency (related to stiffness) together with a static measure of stiffness have shown the legs of non‐injured subjects to respond non‐linearly to decreasing torques. However, the complete paraplegics' legs did not respond non‐linearly but showed constant resonant frequency and stiffness over the range of torques. Peak velocity at resonance (inversely related to damping) gradually increased with increasing torques in both groups. In addition, at a chosen baseline torque of 0·7 N m, resonant frequency and muscle stiffness were significantly lower and peak velocity significantly higher in the paraplegics compared to the non‐injured subjects. Contrary to expectations the thigh muscles in established, complete paraplegia showed a lack of tonic EMG activity. In addition, whilst phasic stretch responses were occasionally seen there was no tonic activity in relation to continued stretch. Since muscles atrophy after paralysis, the smaller muscle bulk may contribute to the lower muscle tone.This publication has 3 references indexed in Scilit:
- POSTURAL THIXOTROPY AT THE HUMAN HIPQuarterly Journal of Experimental Physiology, 1988
- INERTIA, RESONANT FREQUENCY, STIFFNESS AND KINETIC ENERGY OF THE HUMAN FOREARMQuarterly Journal of Experimental Physiology, 1987
- Resonance at the wrist demonstrated by the use of a torque motor: an instrumental analysis of muscle tone in man.The Journal of Physiology, 1984