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

Context: 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).

Objective: 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.

Design: Crossover study.

Setting: Research laboratory.

Patients Or Other Participants: 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.

Intervention(s): 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.

Main Outcome Measure(s): 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.

Results: 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.

Conclusions: Adding NDNG to the warm-up routine increased ROM more than FR and may benefit soccer players.