Ankle stiffness and tissue compliance in stroke survivors: A validation of Myotonometer measurements1  Sarah J. Rydahl, MS, Brenda J. Brouwer, PhD  Archives of Physical Medicine and Rehabilitation  Volume 85, Issue 10, Pages 1631-1637 (October 2004) DOI: 10.1016/j.apmr.2004.01.026

Fig 1 Resistance torque profiles from (A) a control subject and (B) a stroke survivor in response to a 5° perturbation introduced at 500ms. Ankle perturbations were introduced while subjects maintained a 10% of MVC (a) voluntarily and (b) involuntarily by stimulating the muscle nerve, and while they were (c) relaxed. Stiffness measurements derived from these profiles are illustrated: d, total mechanical stiffness; e, nonreflex stiffness; f, reflex stiffness (f=d−e); g, passive stiffness. Intrinsic stiffness was calculated as the difference between d and g (not shown). Note the different y-axis scales. Archives of Physical Medicine and Rehabilitation 2004 85, 1631-1637DOI: (10.1016/j.apmr.2004.01.026)

Fig 2 Mean +1 SD total mechanical stiffness of the ankle and the breakdown into contributing components. The P values indicate the significance of the between-group comparison. Archives of Physical Medicine and Rehabilitation 2004 85, 1631-1637DOI: (10.1016/j.apmr.2004.01.026)

Fig 3 A comparison of the mean (1 SD) muscle compliance recorded at increasing levels of force for each group while the plantarflexors were (A) relaxed and (B) tonically active; and (C) the difference in compliance between the 2 muscle activation states. Archives of Physical Medicine and Rehabilitation 2004 85, 1631-1637DOI: (10.1016/j.apmr.2004.01.026)