Related Experiment Videos
Sex differences in valgus knee angle during a single-leg drop jump.
Kyla A Russell1, Riann M Palmieri, Steven M Zinder
1University of Virginia, Charlottesville, VA, USA.
Journal of Athletic Training
|June 23, 2006
Summary
Women exhibit greater knee valgus during landing compared to men, increasing anterior cruciate ligament injury risk. Gluteus medius activation did not differ between sexes, suggesting it doesn't explain this sex disparity in knee landing mechanics.
Area of Science:
- Biomechanics
- Sports Medicine
- Orthopedics
Background:
- Female athletes have higher anterior cruciate ligament (ACL) injury rates.
- Valgus knee alignment increases ACL strain.
- Gluteus medius (GM) activation may stabilize the leg and limit valgus during landing.
Purpose of the Study:
- Compare frontal-plane knee angle and GM activation between sexes during single-leg drop landing.
- Investigate sex differences at initial contact and maximal knee flexion.
Main Methods:
- Between-groups design with 32 healthy adults (18-30 years).
- Motion analysis laboratory.
- Measured frontal-plane knee angle and GM activation (aRMS) at initial contact and maximal knee flexion.
Main Results:
- Women landed in knee valgus, men in knee varus at initial contact.
- Both sexes showed knee varus at maximal flexion, less in women.
- GM activation increased at maximal flexion but did not differ between sexes.
Conclusions:
- Women demonstrate greater knee valgus during landing than men.
- GM activation does not explain sex differences in knee valgus.
- Increased knee valgus in women may contribute to higher ACL injury rates.