Department of Bioengineering, Stanford University, Stanford, California, USA.
J Orthop Res. 2012 Jun;30(6):927-33. doi: 10.1002/jor.22008. Epub 2011 Nov 15.
Patellofemoral (PF) pain is a common ailment of the lower extremity. A theorized cause for pain is patellar maltracking due to vasti muscle activation imbalance, represented as large vastus lateralis:vastus medialis (VL:VM) activation ratios. However, evidence relating vasti muscle activation imbalance to patellar maltracking is limited. The purpose of this study was to investigate the relationship between VL:VM activation ratio and patellar tracking measures, patellar tilt and bisect offset, in PF pain subjects and pain-free controls. We evaluated VL:VM activation ratio and VM activation delay relative to VL activation in 39 PF pain subjects and 15 pain-free controls during walking. We classified the PF pain subjects into normal tracking and maltracking groups based on patellar tilt and bisect offset measured from weight-bearing magnetic resonance imaging. Patellar tilt correlated with VL:VM activation ratio only in PF pain subjects classified as maltrackers. This suggests that a clinical intervention targeting vasti muscle activation imbalance may be effective only in PF pain subjects classified as maltrackers.
髌股（PF）疼痛是下肢的常见疾病。疼痛的一个理论原因是由于股四头肌激活失衡导致髌骨轨迹异常，表现为股外侧肌：股内侧肌（VL：VM）激活比异常。然而，将股四头肌激活失衡与髌骨轨迹异常联系起来的证据有限。本研究旨在探讨 PF 疼痛患者和无疼痛对照组的 VL：VM 激活比与髌骨跟踪测量值、髌骨倾斜和二分偏移之间的关系。我们在 39 名 PF 疼痛患者和 15 名无疼痛对照组的步行过程中评估了 VL：VM 激活比和 VM 相对于 VL 的激活延迟。我们根据负重磁共振成像测量的髌骨倾斜和二分偏移，将 PF 疼痛患者分为正常跟踪和轨迹不良两组。仅在被归类为轨迹不良的 PF 疼痛患者中，髌骨倾斜与 VL：VM 激活比相关。这表明，针对股四头肌激活失衡的临床干预措施可能仅对被归类为轨迹不良的 PF 疼痛患者有效。
