Effects of Unilateral Lower-extremity Joint Cooling on Movement Biomechanics during Two-legged Jumping and Landing

OBJECTIVES This study examined the immediate effect of unilateral ankle or knee joint cooling on the low-erextremity kinematics and kinetics during two-legged jumping and landing.METHODS Twenty healthy adults randomly completed three data collection sessions for ankle or knee joint cooling, or control. For each session, participants performed two-legged countermovement jumps and lands. For joint cooling, two ice bags were directly placed to the right side and secured with a compression bandage. A three-dimensional motion analysis system (200 Hz) with two floor-embedded force platforms (2000 Hz) was employed to capture the jumping and landing. The cooling effects on kinematical (flight time, and sagittal plane joint angles) and kinetical (peak vertical ground reaction force (vGRF), impulse, and sagittal plane joint moments) variables were examined. A mixed-model analysis of variance was performed for each dependent variable (p≤0.0001 for all tests).RESULTS We did not observe any interactions (flight time: F2,95=0.67, p=0.52; joint angles: F2,209≤2.26, p≥0.10; peak vGRF: F2,209≤1.76, p≥0.20; impulse: F2,209≤2.54, p≥0.10; joint moments: F2,209≤4.80, p≥0.01 for all interactions). Regardless of condition and time (side effect), subjects showed a dominant-leg predominant movement strategy. Specifically, the right side showed a greater peak vGRF (2%), and greater ankle (7%), knee (6%), and hip (11%) joint moments, as compared with the left side during jumping. The same movement pattern was observed during landing that there was greater peak vGRF (11%) and impulse (8%), and greater ankle and knee joint moments (15%). Regardless of time and side (condition effect), subjects with ankle joint cooling showed 5% lesser ankle joint moment during jumping, compared with those who received knee joint cooling (p=0.0001).CONCLUSIONS A 20-min of unilateral ankle or knee joint cooling seems to neither alter vertical jump height nor change movement biomechanics during two-legged jumping and landing.