Few studies indicate that sprint performance may be impaired in football players with a previous hamstring strain injury. This exploratory cross-sectional study aim to compare sprint performance between football players with and without a previous hamstring strain injury. The findings may elucidate potential indications of insufficient rehabilitation following a hamstring strain injury.

Sprint performance data will be collected using the MySprint Iphone Application.

Due to pragmatic reasons and the exploratory nature of this study the aim is to include players on a team level.

Based on the prevalence of hamstring strain injuries the expected number of cases to be included are 10-20 football players with a previous hamstring strain injury, and a corresponding 80-90 number of healthy controls.

No outcomes will be weighted (flat outcome structure).

Inclusion Criteria Controls:

• Able to participate fully in regular football training and matches

Exclusion Criteria Controls:

• Self-reported hamstring strain injury resulting in loss of regular football training sessions or football matches in the preceding 12 months.
• Longstanding injury (>6 weeks) in the lower extremities or trunk in the preceding 12 months.
• Any pain in the lower extremity, pelvis, or spine during testing

Inclusion Criteria Cases:

• Able to participate fully in regular football training and matches
• Self-reported hamstring strain injury resulting in loss of regular football training sessions or football matches in the preceding 12 months.

Exclusion Criteria Cases:

• Longstanding injury (>6 weeks) in the lower extremities (except hamstring strain injury) or trunk in the preceding 12 months.
• Any pain in the lower extremity, pelvis, or spine during testing

Danish competitive football players