Ernst G P, Saliba E, Diduch D R, Hurwitz S R, Ball D W
182 Artillery Post Rd, Fort Sam Houston, TX 78234, USA. gernst@juno. com.
Phys Ther. 2000 Mar;80(3):251-60.
Several studies have demonstrated that patients with knee injury scored within a normal range during one-legged hop tests, yet showed quadriceps femoris muscle weakness with non-weight-bearing isokinetic testing. This study evaluated lower-extremity kinetics while subjects performed a single-leg vertical jump (VJ) and a lateral step-up (LSU) in an attempt to explain this phenomenon.
Using a motion analysis and force platform system, hip, knee, and ankle extension moments of 20 subjects with anterior cruciate ligament (ACL) reconstructions and 20 matched subjects were measured while they performed an LSU and a VJ.
An analysis of variance revealed that the knee extension moment of the ACL-reconstructed extremity was lower than that of the uninjured and matched extremities during the LSU, VJ take-off, and VJ landing. However, there was no difference in summated extension moment (hip + knee + ankle) among extremities during the LSU and VJ take-off. The summated extension moment of the ACL-reconstructed extremity during VJ landing was less than that of the uninvolved and matched extremities.
These results suggest that the hip or ankle extensors may compensate for the knee extension moment deficit. The decrease in summated extension moment in the ACL-reconstructed extremity during VJ landing represents inadequate attenuation of landing forces, which may expose the skeleton and joint structures to injury.
多项研究表明，膝关节损伤患者在单腿跳测试中得分处于正常范围，但在非负重等速测试中显示股四头肌无力。本研究评估了受试者进行单腿垂直跳（VJ）和侧向跨步上台阶（LSU）时的下肢动力学，以试图解释这一现象。
使用运动分析和测力平台系统，在20名前交叉韧带（ACL）重建患者和20名匹配的受试者进行LSU和VJ时，测量他们髋、膝和踝关节的伸展力矩。
方差分析显示，在LSU、VJ起跳和VJ落地过程中，ACL重建肢体的膝关节伸展力矩低于未受伤和匹配肢体。然而，在LSU和VJ起跳过程中，各肢体的总伸展力矩（髋+膝+踝）没有差异。ACL重建肢体在VJ落地时的总伸展力矩小于未受累和匹配肢体。
这些结果表明，髋部或踝部伸肌可能补偿膝关节伸展力矩不足。ACL重建肢体在VJ落地时总伸展力矩的降低代表着地力的衰减不足，这可能使骨骼和关节结构面临受伤风险。
