Warm-Up and Hamstrings Stiffness, Stress Relaxation, Flexibility, and Knee Proprioception in Young Soccer Players.

Abstract

Nerves or fascia may limit motion in young soccer players, thereby contributing to frequent hamstrings injuries. Nerve-gliding exercises and self-myofascial release techniques may enhance range of motion (ROM). To compare the immediate effect of foam rolling (FR) and neurodynamic nerve gliding (NDNG) on hamstrings passive stiffness, viscoelasticity, flexibility, and proprioception during the warm-up of soccer players. Crossover study. Research laboratory. A total of 15 male soccer players (age = 18.0 ± 1.4 years, height = 183.1 ± 6.0 cm, mass = 76.9 ± 7.8 kg) on the same team. The FR and NDNG consisted of 6 sets of 45 seconds with a 15-second rest between sets. Over a 2-week period, participants performed FR and NDNG on 2 separate occasions. Stiffness (between 50% and 80%, and 85% and 95% [STFmax] of maximal knee-extension ROM), viscoelasticity (stress-relaxation test), knee-extension ROM, hamstrings passive-resistance torque (PRT), hip-flexion angle (straight-leg raise test), and active knee-joint position sense. We observed an interaction between time and intervention for STFmax (F1,17 = 5.024, P = .042), knee-extension ROM (F1,17 = 7.371, P = .02), and PRT (F1,17 = 4.876, P = .044). The NDNG technique induced increases in STFmax (t17 = 2.374, P = .03), ROM (t17 = 2.843, P = .01), and PRT (t17 = 2.982, P = .008). Both NDNG and FR led to improved performance on the straight-leg raise test (F1,17 = 87.514, P < .001). No interaction or main effect was found for the stress-relaxation test or active knee-joint position sense. Adding NDNG to the warm-up routine increased ROM more than FR and may benefit soccer players.