Panos Joseph A, Hoffman Joshua T, Wordeman Samuel C, Hewett Timothy E
Department of Biomedical Engineering, Columbus, OH, USA, 43210.
Sports Health and Performance Institute (SHPI) OSU Sports Medicine, Columbus, OH, USA, 43210.
Clin Biomech (Bristol). 2016 Mar;33:7-12. doi: 10.1016/j.clinbiomech.2016.01.010. Epub 2016 Feb 4.
Correction of neuromuscular impairments after anterior cruciate ligament injury is vital to successful return to sport. Frontal plane knee control during landing is a common measure of lower-extremity neuromuscular control and asymmetries in neuromuscular control of the knee can predispose injured athletes to additional injury and associated morbidities. Therefore, this study investigated the effects of anterior cruciate ligament injury on knee biomechanics during landing.
Two-dimensional frontal plane video of single leg drop, cross over drop, and drop vertical jump dynamic movement trials was analyzed for twenty injured and reconstructed athletes. The position of the knee joint center was tracked in ImageJ software for 500 milliseconds after landing to calculate medio-lateral knee motion velocities and determine normal fluency, the number of times per second knee velocity changed direction. The inverse of this calculation, analytical fluency, was used to associate larger numerical values with fluent movement.
Analytical fluency was decreased in involved limbs for single leg drop trials (P=0.0018). Importantly, analytical fluency for single leg drop differed compared to cross over drop trials for involved (P<0.001), but not uninvolved limbs (P=0.5029). For involved limbs, analytical fluency values exhibited a stepwise trend in relative magnitudes.
Decreased analytical fluency in involved limbs is consistent with previous studies. Fluency asymmetries observed during single leg drop tasks may be indicative of abhorrent landing strategies in the involved limb. Analytical fluency differences in unilateral tasks for injured limbs may represent neuromuscular impairment as a result of injury.
前交叉韧带损伤后神经肌肉功能障碍的纠正对于成功重返运动至关重要。落地时膝关节在额状面的控制是下肢神经肌肉控制的常用指标，膝关节神经肌肉控制的不对称会使受伤运动员更容易遭受额外损伤及相关疾病。因此，本研究调查了前交叉韧带损伤对落地时膝关节生物力学的影响。
对20名受伤且已重建的运动员进行单腿下蹲、交叉下蹲和垂直跳动态运动试验的二维额状面视频分析。在ImageJ软件中跟踪膝关节中心位置，落地后持续500毫秒，以计算膝关节内外侧运动速度，并确定正常流畅性，即膝关节速度每秒改变方向的次数。该计算的倒数，即分析流畅性，用于将较大数值与流畅运动相关联。
单腿下蹲试验中，患侧肢体的分析流畅性降低（P = 0.0018）。重要的是，患侧肢体单腿下蹲试验的分析流畅性与交叉下蹲试验相比存在差异（P < 0.001），但健侧肢体无差异（P = 0.5029）。对于患侧肢体，分析流畅性值呈现出相对大小的逐步变化趋势。
患侧肢体分析流畅性降低与先前研究一致。单腿下蹲任务中观察到的流畅性不对称可能表明患侧肢体着陆策略异常。受伤肢体在单侧任务中的分析流畅性差异可能代表损伤导致的神经肌肉功能障碍。
