RR-PL-0766

Monday 17:10, Palau de Congressos, Hall 5, Room 5

SAGITTAL TIBIAL TRANSLATION DURING REHABILITATION EXERCISES AFTER ANTERIOR CRUCIATE LIGAMENT INJURY. Kvist J; Physical Therapy, Dept. Health and Society. Faculty of Health Science, Linköping University, SE-581 85 Linköping, Sweden. PURPOSE: In order to understand the effects of various treatment for knee instability after an anterior cruciate ligament (ACL) injury, it is necessary to examine adaptive motion strategies employed by patients with unstable knee. The purpose of this study was to describe the sagittal tibial translation and EMG activity of muscles v. medialis and lateralis, gastrocnemius and hamstrings, during common rehabilitation exercises, in patients with ACL-deficiency and uninjured controls. RELEVANCE: Rehabilitation is essential in the treatment after an ACL-injury. This study provides some new findings about the stabilization of the knee joint during activity, that are of importance for physical therapists for the construction of rehabilitation programs. SUBJECTS: Twelve patients with a ACL-deficiency and 17 controls participated in this study. METHODS AND MATIERIALS: Sagittal tibial translation was registered with the CA-4000 electrogoniometer during Lachman test (static translation), active extension with 0 and 8kg weight, squat on one leg, rising from and sitting down on a chair on two and one leg, bicycling with 1.5 and 3 kg weight and heel raising on one leg (dynamic translation). Tibial position was expressed relative to the femurotibial position during a passive knee extension. EMG activity, measured with ME-4000, was normalized to the individual maximum isometric voluntary contraction for each muscle. ANALYSES:Two–way ANOVA (analysis of variance) for repeated measures or between groups design was used for the statistical comparisons. RESULTS: The non-weight bearing exercise (active extension) produced large amount of tibial translation and the tibial total anterior- posterior motion was two times greater compared to that during squat and rising from and sitting down on a chair. Weight bearing resulted in anterior positioning of tibia. Heel raising resulted in equal translation values as the squat and the rising from and sitting down on a chair. Bicycling produced the smallest amount of tibial translation. CONCLUSIONS: During weight bearing the total translational movement decreases but tibia is anterior positioned. In contrast to the gradually restraining of the anterior tibia translation in the non-injured knee, tibia in the ACL-injured knee translates anteriorly to one level during weight bearing and continuous further to next level during non-weight bearing. The subjects utilized different amount of their individual joint play (static translation) during the exercises, which may explain why there are no correlation between static translation and the patients´ functional outcome.