PURPOSE To examine whether normalized quadriceps and hamstring strength would predict quadriceps and hamstring muscle activation amplitudes and whether these neuromuscular factors would predict knee kinematics and kinetics during a drop jump task. METHODS Thirty-nine females and 39 males were measured for isometric quadriceps and hamstring strength and were instrumented to obtain surface elec...

abstract background and aim: lack of balance in pattern and activity of quadriceps and hamstring muscles increases the risk of anterior cruciate ligament injury (acl). the purpose of the present study was to investigate the changes in pattern and activity of vastus medialis and semitendinosusmuscles in landing from different heights and to understand if these changes will increase the risk of a...

Recent studies have focused on gender differences in movement patterns as risk factors for ACL injury. Understanding intrinsic and extrinsic factors which contribute to movement patterns is critical to ACL injury prevention efforts. Isometric lower-extremity muscular strength, anthropometrics, and jump-landing technique were analyzed for 2,753 cadets (1,046 female, 1,707 male) from the U.S. Air...

The purpose of this study was to examine the effects of a neuromuscular training (NMT) program on lower-extremity biomechanics in youth female netball athletes. The hypothesis was that significant improvements would be found in landing biomechanics of the lower-extremities, commonly associated with anterior cruciate ligament (ACL) injury, following NMT. Twenty-three athletes (age = 12.2 ± 0.9 y...

BACKGROUND Aquatic plyometric programs are becoming increasingly popular because they provide a less stressful alternative to land-based programs. Buoyancy reduces the impact forces experienced in water. PURPOSE To quantify the landing kinetics during a range of typical lower limb plyometric exercises performed on land and in water. STUDY DESIGN Crossover design. METHODS Eighteen male par...

It is common practice to study jump landing mechanics by having subjects step off a box set at a certain height instead of landing from a jump. This practice assumes that the landing mechanics are similar between stepping off a box and a countermovement jump as long as the heights can be matched. The mechanics of the two methods had never been compared when landing from identical heights. Thus,...

This study aimed to compare the kinematics and kinetics during the landing of hop-jump and step-close-jump movements in order to provide further inferring that the potential risk of ACL injuries. Eleven elite male volleyball players were recruited to perform hop-jump and step-close-jump tasks. Lower extremity kinematics and ground reaction forces during landing in stop-jump tasks were recorded....