Association between lower extremity muscular strength and acute knee injuries in young team-sport athletes

The purpose of this study was to investigate LE muscular strength variables as potential risk factors for all and non-contact acute knee and ACL injuries in young athletes. A total of 188 young (<= 21) male and 174 female basketball and floorball players participated in LE muscular strength tests and were followed up to 3 years. The strength test battery consisted of 1RM leg press, maximal concentric isokinetic (60 degrees /s) quadriceps and hamstrings, and maximal isometric hip abductor strength. The outcomes were a new acute knee or ACL injury and a new acute non-contact knee or ACL injury. A total of 51 (17 in males and 34 in females) new acute knee injuries registered and 17 (one in males and 16 in females) of these were ACL injuries. In the adjusted Cox regression models, only lower maximal hip abduction strength (kg/kg) was significantly associated with an increased risk of all knee injuries in males (HR 1.80 [95% CI, 1.03-3.16] for 1 SD decrease in hip abduction). However, ROC curve analysis showed an area under the curve 0.66 revealing that maximal hip abduction strength test cannot be used as a screening tool for an acute knee injury in young male athletes.