Home Current Issue Previous Issues Published Ahead-of-Print Collections For Authors Journal Info
Skip Navigation LinksHome > October 1996 - Volume 28 - Issue 10 > Eccentric knee flexor torque following anterior cruciate lig...
Medicine & Science in Sports & Exercise:
Clinical Sciences: Clinical Investigations

Eccentric knee flexor torque following anterior cruciate ligament surgery

OSTERNIG, LOUIS R.; JAMES, CHARLES R.; BERCADES, DAVID T.

Collapse Box

Abstract

The purposes of this study were to compare eccentric knee flexor torque and muscle activation in the limbs of normal (NOR) subjects and in subjects who had undergone unilateral ACL autograft surgical reconstruction (INJ) and to assess the effect of movement speed on EMG/torque ratios and eccentric-concentric actions. Fourteen subjects (7 NOR and 7 INJ) were tested for knee eccentric flexor torque and EMG activity at four isokinetic speeds(15°, 30°, 45°, and 60°·s-1). Results revealed that post-surgical limbs (ACL) produced significantly less (P < 0.05) eccentric torque and flexor EMG activity at 60°·s-1 than uninjured (UNI) contralateral limbs. Eccentric torque rose significantly as speed increased from 45° to 60°·s-1 for surgical group uninjured limbs and NOR group left and right limbs. Eccentric flexor torque increased with speed for both groups and approximated equality with concentric extensor torque at 60°·s-1 for INJ group ACL and UNI limbs. Concentric flexor muscle EMG/torque ratios were 30-191% greater than eccentric muscle actions across groups and speeds. The results suggest that ACL dysfunction may result in reduced eccentric flexor torque at rapid movement speeds, that eccentric flexor torque increases with movement speed and may have the capacity to counter forceful extensor concentric torque, and that eccentric muscle actions produce less muscle activation per unit force than concentric actions which may reflect reduced energy cost.

©1996The American College of Sports Medicine

Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us