Sprint Performance in Football Players With a Previous Hamstring Injury

Study Overview
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Brief Summary
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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).

Official Title
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Sprint Performance in Football Players With a Previous Hamstring Injury Compared to Healthy Controls: An Exploratory Cross-sectional Study

Conditions
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Sprint Performance, Hamstring Injury

Intervention / Treatment
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* Other: Repeated-sprint test


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Case<br>Football players with a previous self-reported hamstring strain injury in the preceding 12 months | Other: Repeated-sprint test<br>* 6x30-meter sprint interspersed with 90-s rest<br>|
| Control<br>Football players without a previous self-reported hamstring strain injury in the preceding 12 months | Other: Repeated-sprint test<br>* 6x30-meter sprint interspersed with 90-s rest<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Theoretical maximal force | Measured using the MySprint Application during a repeated-sprint test consisting of 6x30-m sprints. The outcome measure is exploratory. | Baseline | 
| Theoretical maximal velocity | Measured using the MySprint Application during a repeated-sprint test consisting of 6x30-m sprints. The outcome measure is exploratory. | Baseline | 
| Theoritical maximal power output | Measured using the MySprint Application during a repeated-sprint test consisting of 6x30-m sprints. The outcome measure is exploratory. | Baseline | 
| Slope of the linear decrease on ratio of force as sprint velocity increases | Measured using the MySprint Application during a repeated-sprint test consisting of 6x30-m sprints. The outcome measure is exploratory. | Baseline |