The majority of football injuries occur in the last 15 minutes of each half, strongly implicating fatigue as a causative factor in football related injuries. The potential mechanisms for this increased risk of injury have not been well established. This study investigated the effects of football-simulated fatigue on neuromuscular function and dynamic balance response1.
Fifteen male players completed approximately 90 minutes of exercise using the modified Loughborough Intermittent Shuttle Test, a test designed to replication the rigors of a football match, or seated rest (control condition) on separate days. Maximal and explosive isometric knee flexion (KF) and knee extension (KE) voluntary torque were assessed pre-and post each activity. Maximal and explosive KF/KE ratios were then calculated. Centre of mass (COM) response to unexpected anterior and posterior platform perturbations of balance were also assessed pre-and post-condition.
Football-simulated fatigue resulted in reduced knee flexion (15%) and knee extension (12%) maximal torque, but was not found to reduce explosive torque of either muscle group, nor explosive knee flexion to knee extension ratio. Football-simulated fatigue resulted in impaired balance response (11% increase in COM displacement) to unexpected perturbation in the posterior but not the anterior direction.
It seems likely that impaired balance (as well as absolute muscle strength), may be contributory factors toward increased injury risk in the latter portion of football games. These findings likely highlight the influence of fatigue on sensory and proprioceptive processes and may encourage football clinicians to improve proprioceptive processes in a fatigued state for injury prevention.
Thanks to the team at ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, for providing this FastFact. ASPETAR is a FIFA Medical Centre of Excellence based in Doha.
1Behan, F.P., Wills, S., Pain, M.T., Folland, J.P. (2018). Effects of football simulated fatigue on neuromuscular function and whole-body response to disturbances in balance. Scandinavian Journal of Medicine & Science in Sports. 28(12):2547-2557. DOI: 10.1111/sms.13261.