The effects of strength training on the lower extremity biomechanics of female recreational athletes during a stop-jump task.
BACKGROUND
Strength training is considered a strategy for anterior cruciate ligament injury prevention. Little is known about the contribution of strength training to knee and hip biomechanics.


OBJECTIVE
Lower extremity muscle strength training alters knee and hip biomechanics during a stop-jump task.


METHODS
Controlled laboratory study.


METHODS
Knee and hip 3-dimensional kinematic and kinetic data were collected for 66 female recreational athletes (33 intervention and 33 control) while performing 3 stop-jump tasks before and after completing a 9-week strength-training program targeting the quadriceps, hamstrings, gluteus medius, and gluteus maximus (intervention) or a 9-week period of no strength training (control). Maximum voluntary isometric contraction strength data were also collected for each subject before the stop-jump tasks in each data collection session. Knee and hip joint angles as well as resultant forces and moments were calculated.


RESULTS
The intervention group increased in strength (P < .001 for all muscles). No significant differences were observed in knee and hip kinematics and kinetics between groups before and after the strength-training protocol.


CONCLUSIONS
Strength training alone does not alter knee and hip kinematics and kinetics in female recreational athletes. Further research is needed to determine the effect of strength training in combination with other intervention methods on lower extremity biomechanics.


CONCLUSIONS
Strength training as a single intervention method may not be sufficient to reduce the risk of noncontact anterior cruciate ligament injury in female recreational athletes.
Herman
Daniel C
DC
University of North Carolina, Chapel Hill, North Carolina, USA.
Weinhold
Paul S
PS
Guskiewicz
Kevin M
KM
Garrett
William E
WE
Yu
Bing
B
Padua
Darin A
DA
D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000517:prevention & control; D001696:Biomechanical Phenomena; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D007718:Knee Injuries / Q000517:prevention & control; D007719:Knee Joint / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology*; D009068:Movement / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D009657:North Carolina; D013647:Task Performance and Analysis; D014891:Weight Lifting / Q000502:physiology*