Ankle or knee joint cooling alters countermovement but not squat jump height in healthy collegiate athletes

BACKGROUND: Ankle or knee joint cooling has shown to increase muscle activation in controlled laboratory measurements. OBJECTIVE: To examine if a bilateral 20-min lower-extremity joint cooling alters maximal vertical jump heights over time. METHODS: Twenty-one healthy male basketball and volleyball players participated in this cross over study. One of three conditions was assigned for each session (ankle or knee joint cooling, or control). Subjects performed three maximal vertical jumps with (countermovement jump: CMJ) and without (squat jump: SJ) using muscle pre-stretching and arm swinging at baseline and after condition (0-, 10-, 20-, and 30-min post). To test joint cooling effects over time, we performed 3 x 5 mixed model ANOVAs and Tukey-Kramer tests. RESULTS: Both joint cooling altered CMJ heights (F-8,F-280 = 2.29; p = 0.02). Compared to the baseline measurements, subjects jumped lower after condition (ankle: 4.3 cm; knee: 3.5 cm, p < 0.0001) but their jump heights returned to the baseline levels after 10-min post-joint cooling (p > 0.16). SJ heights did not change at any time interval (F-8,F-280 = 1.67; p = 0.11). CONCLUSIONS: Bilateral joint cooling does not produce a facilitatory effect during a high-intensity dynamic movement. Cryotherapy at the lower extremity joints should be done ten minutes before games or practices to avoid a performance deficit in vertical jump heights.