Personal tools
You are here: Home Research Publications archive Effect of knee flexion angle on active joint stiffness
Navigation
 
Document Actions

Effect of knee flexion angle on active joint stiffness

by McHugh MP, Hogan DE. last modified 2009-10-09 15:17

Acta Physiol Scand. 2004 Mar;180(3):249-54.

AIM: The purpose of this study was to determine if active joint stiffness measured during maximum voluntary knee extension contractions was affected by knee flexion angle. METHODS: Eighteen subjects volunteered (11 male, seven female). A stretch was imposed on isometric knee contractions performed at 30 degrees, 50 degrees, 70 degrees, 90 degrees, and 110 degrees of knee flexion. Active joint stiffness was computed from the increase in torque relative to the change in knee flexion angle for the first 50 ms of the stretch (approximately 1.5 degrees ) and corrected for effects of gravitational component due to leg mass and passive tension. RESULTS: There was a plateau in knee extension torque between 70 degrees and 90 degrees with lower values at all other angles (P < 0.05). Peak active joint stiffness occurred at 70 degrees with lower values (P < 0.05) at all other angles except 50 degrees. Stiffness at 70 degrees (441.1 +/- 189.9 Nm rad-1) was 49% higher than at 30 degrees and 45% higher than at 110 degrees. CONCLUSION: Active joint stiffness was dependent on knee flexion angle. Peak joint stiffness during maximal contractions occurred at, or prior to, the optimal angle for torque production for all subjects.

Powered by Plone, the Open Source Content Management System

This site conforms to the following standards: