Weinhandl Joshua T, Earl-Boehm Jennifer E, Ebersole Kyle T, Huddleston Wendy E, Armstrong Brian S R, O'Connor Kristian M
Department of Human Movement Sciences, Old Dominion University, Norfolk, VA 23529, USA.
Department of Kinesiology, University of Wisconsin-Milwaukee, Milwaukee, WI 53202, USA.
Clin Biomech (Bristol). 2014 Aug;29(7):752-9. doi: 10.1016/j.clinbiomech.2014.05.013. Epub 2014 Jun 11.
Dynamic knee stability is considered a critical factor in reducing anterior cruciate ligament loads. While the relationships between hamstring force production and anterior cruciate ligament loading are well known in vitro, the influence of hamstring strength to anterior cruciate ligament loading during athletic maneuvers remains unknown. Therefore, the purpose of this study was to determine the influence of hamstring strength on anterior cruciate ligament loading during anticipated sidestep cut.
Seventeen recreationally active females were recruited to perform sidestep cutting maneuvers pre/post an acute hamstring strength reduction protocol. Kinematics and kinetics were calculated during the cut and a musculoskeletal model was used to estimate muscle, joint, and anterior cruciate ligament loads. Dependent t-tests were conducted to investigate differences between the two cutting conditions.
Anterior cruciate ligament loading increased by 36% due to reduced hamstring strength. This was mostly due to a 44% increase in sagittal plane loading and a 24% increase in frontal plane loading. Post strength reduction sidestep cuts were also performed with decreased anterior tibiofemoral shear force, an outcome that would theoretically reduce anterior cruciate ligament loading. However, the overall decrease in hamstring force production coupled with a more axial hamstring line of action yielded a net increase in anterior cruciate ligament loading.
These results suggest that decreased hamstring strength significantly increases anterior cruciate ligament loading during anticipated sidestep cutting. Additionally, these results support the premise that preseason screening programs should monitor hamstring strength to identify female athletes with potential deficits and increased injury risk.
动态膝关节稳定性被认为是减少前交叉韧带负荷的关键因素。虽然在体外，腘绳肌力量产生与前交叉韧带负荷之间的关系已为人熟知，但在运动动作中，腘绳肌力量对前交叉韧带负荷的影响仍不清楚。因此，本研究的目的是确定在预期的侧步切入动作中，腘绳肌力量对前交叉韧带负荷的影响。
招募了17名有运动习惯的女性，在急性腘绳肌力量降低方案前后进行侧步切入动作。在切入过程中计算运动学和动力学参数，并使用肌肉骨骼模型估计肌肉、关节和前交叉韧带的负荷。采用配对t检验来研究两种切入条件之间的差异。
由于腘绳肌力量降低，前交叉韧带负荷增加了36%。这主要是由于矢状面负荷增加了44%，额状面负荷增加了24%。力量降低后侧步切入时，胫股前向剪切力也降低，从理论上讲，这一结果会减少前交叉韧带的负荷。然而，腘绳肌力量产生的总体下降，加上腘绳肌作用线更偏向轴向，导致前交叉韧带负荷净增加。
这些结果表明，在预期的侧步切入动作中，腘绳肌力量降低会显著增加前交叉韧带的负荷。此外，这些结果支持这样一个前提，即季前筛查计划应监测腘绳肌力量，以识别有潜在缺陷和受伤风险增加的女性运动员。
