Author(s): Jordan Crum
Mentor(s): A. Wayne Johnson, Malorie Wilwind
Institution BYU
Tendons in the body connect working muscles to moving bones and play key roles in athletes’ strength and speed. Understanding the relationship between sprint speed and total tendon cross sectional area (CSA) of the hamstrings (semitendinosus, semimembranosus, biceps femoris-long head and biceps femoris-short head) and eccentric hamstring strength (EHS) when accounting for weight will allow players to better prepare for success in football. Purpose: To examine the relationship between sprint speed and tendon CSA and EHS when accounting for weight. Methods: This secondary analysis of HAMIR data involved uninjured, actively rostered collegiate American football players, excluding linemen. Participants underwent MRI scans (to measure tendon CSA), a sprint speed test and a strength test (force exerted from doing Nordic curls on a Norbord device). Sprint speed was measured using timing gate technology with sensors at the 0- and 60-yard lines. Measurements of EHS were taken by properly positioning each athlete on the NordBord and instructing them to slowly lower themselves while resisting with their hamstrings. Each athlete performed three sub-maximal warm up trials and three maximum effort trials. The peak force (PF) and fastest sprint speed of the trials were used for statistical analysis. Results: A linear regression model showed a weak prediction for sprint speed when considering total CSA of the hamstrings, EHS, and accounting for weight (R2 = 0.29, p = <0.01). Conclusion: The results of the linear regression model suggest that while tendon CSA, EHS, and weight provide some insight into sprint performance, they explain only about 29% of the variation in sprint speed. This indicates a weak predictive relationship between these factors and sprint speed. The findings highlight that while tendon CSA and eccentric strength are important components of an athlete’s overall physical profile, other factors, not captured in this study, may play a significant role in determining sprint performance.