Objectives: The role of the lumbar spine to influence hamstring extensibility remains unclear. This study aimed to compare the immediate effects of L4/5 mobilisations on measures of neural and muscle hamstring extensibility in asymptomatic elite male soccer players.
Subjects: Twenty-five male soccer players from an English Premier League team with no current injury.
Methods: Players were randomly assigned to one of two groups, intervention or control. Neural hamstring extensibility was measured pre- and post-mobilisations by the straight leg raise test. The muscle biased component was measured by the passive knee extension test. Participants in the intervention group received specific lumbar mobilisations to the unilateral L4/5 zygapophyseal joint, 3 times for 1 minute, with each mobilisation separated by a 1-minute recovery, nominated by dominant kicking foot. The control group received no mobilisations between pre- and post-measures. Data were analysed using magnitude-based inferences.
Results: Lumbar mobilisations had a very likely small beneficial effect on the straight leg raise test (6.3%; 90% confidence limits ±2.7%) and a likely small beneficial effect on the passive knee extension test (-23%; ±14%).
Conclusion: Specific lumbar mobilisations have the ability to increase the neural and muscle extensibility of the hamstring muscle group in elite male soccer players in the immediate term.