Sagittal plane knee motion in the ACL-deficient knee during body weight shift exercises on different support surfaces

Experimental design with group comparisons.

To compare anterior tibial translation and muscle activity among different exercises for early weight-bearing and neuromuscular training in individuals with a unilateral anterior cruciate ligament (ACL) injury and in uninjured controls.

The effects of exercise and activity on tibial translation must be taken into consideration during rehabilitation after ACL injury.

Twelve patients with an ACL-deficient knee and 12 age- and gender-matched controls participated in the study. Sagittal tibial translation and muscle activity were registered during the Lachman test (static translation) and 4 body weight shift exercises (dynamic translation). A Student t test with Bonferroni correction and analysis of variance were used for the statistical analysis.

Forward-backward body weight shift exercise resulted in smaller anterior tibial translation compared to body weight shift from side to side. Analysis of EMG activity could not explain this difference in anterior tibial translation. The amount of anterior tibial translation or EMG activity did not change when the exercises were performed on a trampoline compared to a firm surface.

Forward-backward weight shifting may be preferable in initial rehabilitation after ACL injury compared to body weight shift from side to side.