A decade of NFL injury data reveals that more than half of all hamstring strains happen in seven weeks — and the athletes most at risk are the ones who can least afford to miss time.
Hamstring strains are the most common soft-tissue injury in professional football. Every team knows this. What most organizations did not have — until this study — was the data to understand when, where, and in whom these injuries actually concentrate. Not at the level of a single roster. At the level of an entire league, over an entire decade.
In a study published in The American Journal of Sports Medicine, Dr. Marcus Elliott and colleagues analyzed 1,716 hamstring strains across every NFL team over ten consecutive seasons using the league's Injury Surveillance System. The dataset was — and remains — one of the largest prospective analyses of hamstring injuries in professional sport. The patterns it revealed should have changed how organizations approach their most vulnerable period of the calendar.
The finding
The preseason
concentration
More than half of all hamstring strains — 51.3% — occurred during the seven-week preseason. The preseason practice injury rate was 4.6 times higher than the regular-season practice rate: 0.82 per 1,000 athlete-exposures versus 0.18. Not marginally higher. Nearly five times.
This is not a minor seasonal fluctuation. It is a structural vulnerability built into how organizations prepare their athletes for the season. Seven weeks of preseason accounted for more hamstring injuries than seventeen weeks of regular-season play.
The athletes
Who absorbs
the cost
The position breakdown was equally telling. Defensive backs accounted for 23.1% of all hamstring strains. Wide receivers accounted for 20.8%. Special teams players made up 13.0%. These are the athletes whose game depends on explosive acceleration and maximum-velocity sprinting — the exact movement demands that load the hamstring most aggressively.
Among wide receivers and defensive backs specifically, the noncontact rate climbed above 92%. These injuries were not happening on collisions or tackles. They were happening on sprints, cuts, and acceleration efforts — during practice.
81.5% noncontact
Across the entire dataset, 81.5% of hamstring strains were noncontact. The hamstring was not failing because of external impact. It was failing because the mechanical demands placed on it exceeded what it could tolerate at that moment — during high-speed running, in athletes whose positions require exactly that.
This distinction matters because noncontact injuries carry a different implication than contact injuries. Contact is unpredictable. Noncontact mechanical failure, at population scale, follows patterns. Patterns that can be identified. Patterns that can be addressed.
What this meant for the field
The concentration of noncontact hamstring injuries during preseason, among the fastest players on the field, pointed to a load management problem — not a contact or collision problem. When organizations ramp training volume and intensity too quickly for athletes whose positions demand explosive speed, the hamstring bears the cost.
This study was among the first to demonstrate, at league scale, that hamstring injuries in professional football are not random. They cluster by time of year, by position, and by movement demand. The implication is that a meaningful percentage of these injuries are preventable — if organizations treat preseason conditioning as a data problem rather than a tradition.
The work reflected an approach that would become the foundation of P3's research philosophy: use large-scale, prospective injury data to identify the patterns that drive risk — then give teams the tools to intervene before the injury occurs. The question was never whether hamstring strains are common. It was whether organizations could see them coming.
Methodology note
This research analyzed injury data prospectively collected by certified athletic trainers for all NFL teams between 1989 and 1998, recorded in the NFL's Injury Surveillance System. The dataset included 1,716 hamstring strains across ten consecutive seasons. Variables collected included team, date of injury, activity at time of injury, injury severity, position played, mechanism of injury, and history of previous injury. Full methodology and statistical outputs are available in the published paper.
Citation: Elliott MCCW, Zarins B, Powell JW, Kenyon CD. Hamstring Muscle Strains in Professional Football Players: A 10-Year Review. Am J Sports Med. 2011;39(4):843-850. doi:10.1177/0363546510394647
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