フォームローリングと固有受容神経筋促進ストレッチングの急性効果

実験的：Foam Rolling Group

Participants completed a standardized 5-minute light-intensity aerobic cycling warm-up, followed by unilateral hamstring foam rolling on the dominant lower limb. Foam rolling was performed for 3 sets of 30 seconds, for a total application time of 90 seconds.

他の：Foam Rolling

Participants performed unilateral hamstring foam rolling on the dominant lower limb in a long-sitting position on a firm, flat surface. The foam roller was positioned under the hamstring region, and participants slowly rolled back and forth between the ischial tuberosity and the popliteal fossa under sustained body-weight pressure. The protocol consisted of 3 sets of 30 seconds, for a total application time of 90 seconds. Participants were instructed to apply the maximum tolerable pressure that did not produce pain.

実験的：PNF Stretching Group

Participants completed a standardized 5-minute light-intensity aerobic cycling warm-up, followed by unilateral PNF stretching of the hamstring on the dominant lower limb. Four 30-second repetitions were performed, for a total application time of 120 seconds.

他の：Proprioceptive Neuromuscular Facilitation Stretching

Participants received unilateral PNF stretching of the hamstring on the dominant lower limb in a long-sitting position with the knee fully extended. Each repetition consisted of a 5-second maximal isometric hamstring contraction, followed by 5 seconds of relaxation and 20 seconds of passive stretching. The therapist provided manual resistance during the isometric contraction and guided the participant into the stretch position. Four repetitions were performed, for a total application time of 120 seconds.

Hamstring Flexibility Assessed by the Sit-and-Reach Test

Hamstring flexibility was assessed using the Baseline® Sit and Reach Flexibility Tester. Participants sat with both knees fully extended, the lower limbs together, and the soles of the feet placed flat against the testing device. Participants reached forward as far as possible without flexing the knees. Three trials were performed, and the mean value was recorded in centimeters (cm). Higher values indicate greater flexibility.

Vertical Jump Performance

Vertical jump performance was assessed using a standing vertical jump test. Standing reach height was first recorded. Participants then performed a countermovement jump and reached as high as possible. Vertical jump height was calculated as the difference between jump reach height and standing reach height. Three trials were performed, and the highest value was recorded in centimeters (cm). Higher values indicate greater vertical jump performance.

Isometric Knee Flexion Strength

Isometric knee flexion strength was measured using a digital handheld dynamometer (J Tech Commander Muscle Tester). Participants were seated with the hips and knees flexed to 90°. The dynamometer was positioned on the posterior aspect of the lower leg, 5 cm proximal to the lateral malleolus. Participants performed maximal isometric knee flexion for 3 seconds. Three trials were performed with 60 seconds of rest between trials, and the highest force value sustained for more than 0.5 seconds was recorded in kilogram-force (kgf). Higher values indicate greater isometric knee flexion strength.

Hamstring Pressure Pain Threshold

Pressure pain threshold was assessed over the hamstring region using a digital pressure algometer (Baseline FDK 10). Participants were positioned prone, and the algometer probe was applied perpendicular to the most sensitive point of the hamstring region. Pressure was gradually increased at approximately 1 kgf/cm² every 3 seconds until the participant first reported pain. Three measurements were performed with 20-second intervals between trials, and the lowest value was recorded for analysis. Higher values indicate a higher pressure pain threshold.

Intervention-Related Perceived Exertion

Intervention-related perceived exertion was assessed immediately after the assigned intervention using a single-item 0-10 numerical rating scale (NRS), anchored from 0 (no exertion) to 10 (maximal exertion). Higher scores indicate greater perceived exertion.