PURPOSE: To determine how sex and fatigue affect lower limb kinematics, kinetics, and muscle activity during unanticipated side-step cutting. METHODS: Twenty-three physically active subjects (men 11, women 12) performed 10 successful trials of cutting manoeuvres each to either side under unanticipated conditions in response to 2 light emitting diodes before and after fatigue conditions. Data were analysed and compared regarding sex and fatigue conditions using two-way repeated measures analysis of variance. RESULTS: After fatigue-inducing exercise, women demonstrated larger impulses of ground reaction force (IGRF) during the first 50 ms (2.4 ± 0.8 vs. 2.1 ± 0.9, P < 0.05) than did men. Significant primary effects of sex indicated that women showed a smaller hip flexion angle at initial contact (40.4 ± 6.9° vs. 49.7 ± 9.1°, P < 0.05) and at maximum flexion angle (41.3 ± 7.7° vs. 51.4 ± 9.0°, P < 0.05) compared with men. Significant primary effects of fatigue were observed in the gluteus maximus muscle during 50 ms before initial contact (+21.5 ± 48.3 %, P < 0.05) and in the semimembranosus muscle during 50 ms before initial contact (-6.2 ± 20.1 %, P < 0.05) and the first 50 ms of side-step cutting (-7.9 ± 26.6 %, P < 0.05). CONCLUSIONS: Our results suggest that sex differences, especially larger IGRF in a fatigue state combined with less hip flexion angle, lead to women having a higher risk for anterior cruciate ligament (ACL) injury. These findings may contribute to understanding the underlying mechanism of injury and development of preventive exercises against ACL injury.
PURPOSE: To determine how sex and fatigue affect lower limb kinematics, kinetics, and muscle activity during unanticipated side-step cutting. METHODS: Twenty-three physically active subjects (men 11, women 12) performed 10 successful trials of cutting manoeuvres each to either side under unanticipated conditions in response to 2 light emitting diodes before and after fatigue conditions. Data were analysed and compared regarding sex and fatigue conditions using two-way repeated measures analysis of variance. RESULTS: After fatigue-inducing exercise, women demonstrated larger impulses of ground reaction force (IGRF) during the first 50 ms (2.4 ± 0.8 vs. 2.1 ± 0.9, P < 0.05) than did men. Significant primary effects of sex indicated that women showed a smaller hip flexion angle at initial contact (40.4 ± 6.9° vs. 49.7 ± 9.1°, P < 0.05) and at maximum flexion angle (41.3 ± 7.7° vs. 51.4 ± 9.0°, P < 0.05) compared with men. Significant primary effects of fatigue were observed in the gluteus maximus muscle during 50 ms before initial contact (+21.5 ± 48.3 %, P < 0.05) and in the semimembranosus muscle during 50 ms before initial contact (-6.2 ± 20.1 %, P < 0.05) and the first 50 ms of side-step cutting (-7.9 ± 26.6 %, P < 0.05). CONCLUSIONS: Our results suggest that sex differences, especially larger IGRF in a fatigue state combined with less hip flexion angle, lead to women having a higher risk for anterior cruciate ligament (ACL) injury. These findings may contribute to understanding the underlying mechanism of injury and development of preventive exercises against ACL injury.
Authors: Michael J Decker; Michael R Torry; Douglas J Wyland; William I Sterett; J Richard Steadman Journal: Clin Biomech (Bristol, Avon) Date: 2003-08 Impact factor: 2.063
Authors: Letha Y Griffin; Marjorie J Albohm; Elizabeth A Arendt; Roald Bahr; Bruce D Beynnon; Marlene Demaio; Randall W Dick; Lars Engebretsen; William E Garrett; Jo A Hannafin; Tim E Hewett; Laura J Huston; Mary Lloyd Ireland; Robert J Johnson; Scott Lephart; Bert R Mandelbaum; Barton J Mann; Paul H Marks; Stephen W Marshall; Grethe Myklebust; Frank R Noyes; Christopher Powers; Clarence Shields; Sandra J Shultz; Holly Silvers; James Slauterbeck; Dean C Taylor; Carol C Teitz; Edward M Wojtys; Bing Yu Journal: Am J Sports Med Date: 2006-09 Impact factor: 6.202
Authors: Danielle Potter; Kellie Reidinger; Rebecca Szymialowicz; Thomas Martin; Donald Dione; Richard Feinn; David Wallace; Juan C Garbalosa Journal: Int J Sports Phys Ther Date: 2014-10