Proprioception of Knee Joint in Athletes and Non-Athletes Obese.

BACKGROUND Proprioception plays an integral role in the neuromotor control of the knee joint. The objective of this study was to evaluate the relationship of knee joint proprioception deficit and regular exercise activities with obesity. MATERIALS & METHODS In this case control study, we had 60 participants, aged 18 to 35 in four groups (15 athletes obese; 15 athletes with normal weight; 15 non-athletes obese; 15 non-athletes with normal weight). The average Body Mass Index for the obese groups was 33.50±(3.10) kg/m2 and for the normal weight groups was 23.77±(2.94) kg/m2. We used a Biodex Multi-Joint System 4 Isokinetic Dynamometer to examine proprioception acuity as the amount of a subject's error when trying to reproduce a test knee extension angle (a measure of the joint position sense). We tested proprioception actively (active reproduction test; AAR) and passively (passive reproduction test; PAR) in the right leg. RESULTS The non-athlete obese group had significantly poorer proprioception acuity in the knee extension movement compared to the normal weight groups and also compared to the athlete obese group. For knee active angle reproduction test AAR, a significant difference was found (p=0.011). The results for passive angle reproduction test PAR, revealed no significant differences between the four groups (p=0.596). CONCLUSIONS The obese groups showed a deficit in the proprioception function in knee extension movement. Furthermore, the findings suggest that doing regular weight bearing training is associated with better proprioceptive function, even in obese groups. It could manifest that the deleterious effect of obesity on the knee joint proprioception might be stronger than the beneficial influence of exercise training.