Sex-Specific Muscle Activity and Kinematics of the Posterior Kinetic Chain Targeting Hamstring Strengthening Exercises and Sprinting: A Cross-Sectional Study.

Only 8 male and 12 female athletes were studied, so sex comparisons were small and unequal. Participants were healthy, well-trained sprint athletes without recent lower-extremity injury or pain, so results may not apply to injured or less-trained patients. Female athletes were recruited by convenience sampling from clubs and students, which may limit generalizability. Surface EMG measured one area of each muscle and can be affected by cross-talk and sex-dependent subcutaneous tissue. Muscle activity was not directly converted to muscle force, and exercise speed may have influenced activity more than task demands. Exercise intensity was adjusted to control load, which may have changed the movement pattern and increased variability in angles and activity.

The authors reported no professional relationships with companies or manufacturers that would benefit from the results.

Do not conclude that these exercises prevent hamstring injury or are better for one sex. The study measured muscle electrical activity and joint angles in 20 healthy sprint athletes, not injury outcomes, and sex differences were found in a small, unequal sample.