Effect of cooling one side of a knee joint on one-legged vertical jump

The effects of cryotherapy on both muscles and joints have been studied using various techniques. The results on lower-extremity functional performance have been controversial. Replication of various aspects of previous studies, with appropriate modifications, will help to standardize cryotherapy interventions. The aims of this study were to examine the reliability of the single leg drop jump test and to evaluate the effects of 20 minutes knee joint cryotherapy application on the performance of this test in physical education students. Data were gathered using 52 subjects (age: 22.17 ± 1.53 year; body-mass: 74.83±11.90kg; Height: 1.78±0.08m). Twenty-two of them took part in reliability analysis of the single leg drop jump and all of the 52 participated in testing joint cooling effects. Reliability analyses were established by determining intraclass correlation coefficient and standard error of measurement. The sensitivity of agility tests was revealed by comparing standard error of measurement to the value of the smallest worthwhile change. The intraclass correlation coefficient that aims to assess relative reliability of the single leg drop jump was of 0.83. The standard error of measurement (7.65%) for absolute reliability was <10%. The single leg drop jump capacity to detect change is "good", its standard error of measurement (1.98) was smaller than the smallest worthwhile change (6.77). The 20 minutes knee joint cooling has not affected single leg drop jump height, immediately and 20 minutes after cryo-stimulation. The SLDJ is a reliable tool for the evaluation of vertical jump. A unilateral knee joint cooling does not produce any significant differences, between the pre-and the first post-cryo-stimulation single leg drop jump, as well as the pre-and the second 20 minutes post-cryo-stimulation single leg drop jump.