Normalized Eccentric Hamstring Strength in Collegiate American Football: Position-Based Norms and Longitudinal...

Area of Science:

• Sports Science
• Biomechanics
• Strength and Conditioning

Background:

• Eccentric hamstring strength is crucial for athletic performance and injury prevention in American football.
• Establishing position-specific strength norms is essential for targeted training and rehabilitation.
• Understanding longitudinal strength patterns can inform long-term athlete development.

Purpose of the Study:

• To establish normative values for normalized eccentric hamstring strength in collegiate American football players.
• To evaluate differences in normalized strength based on player position, age, and team affiliation.
• To assess longitudinal changes in normalized eccentric hamstring strength across competitive seasons.

Main Methods:

• Eccentric hamstring strength was measured using the NordBord device in 332 NCAA Division I athletes.
• Strength was normalized to body mass (N·kg-1).
• Multiple linear regression and repeated measures ANOVA were used to analyze positional, demographic, and longitudinal data.

Main Results:

• Skill, power, and special teams athletes demonstrated significantly greater normalized eccentric hamstring strength than linemen.
• Age and team affiliation were significant predictors of normalized strength.
• Longitudinal analysis revealed no significant changes in normalized strength over three competitive seasons.

Conclusions:

• Normalized eccentric hamstring strength norms vary meaningfully by player position and team program.
• Position-specific strength benchmarks are valuable for guiding training, rehabilitation, and return-to-play protocols.
• Normalized strength appears stable in experienced collegiate American football players across competitive seasons.