Acute Effects of Patellar Tendon Ultrasound on Countermovement Jump Performance

This randomized, double-blind, controlled trial aims to investigate the acute effects of therapeutic ultrasound applied to the patellar tendon on vertical jump performance in healthy university students. Therapeutic ultrasound is widely used in physiotherapy to influence soft tissue properties through thermal and mechanical effects; however, its immediate impact on explosive lower-extremity performance and neuromuscular function remains unclear. Participants will be randomly assigned to either a therapeutic ultrasound group or a sham ultrasound (placebo) group. In the intervention group, therapeutic ultrasound will be applied to the patellar tendon using a frequency of 1 MHz and an intensity of 1.5 W/cm² in continuous mode for 5 minutes. In the control group, a sham ultrasound procedure will be performed using the same device and duration without delivering therapeutic energy. Both the participants and the outcome assessor will be blinded to group allocation. Vertical jump performance will be evaluated using the countermovement jump (CMJ) test recorded with the My Jump 2 smartphone application. In addition, quadriceps muscle strength will be measured using a hand-held dynamometer, and knee joint position sense will be assessed using a joint position reproduction test. All measurements will be conducted before and immediately after the intervention. This study will provide evidence regarding whether therapeutic ultrasound applied to the patellar tendon can acutely influence explosive performance, muscle strength, and proprioception in healthy individuals.