Cowan S M, Bennell K L, Hodges P W, Crossley K M, McConnell J
School of Physiotherapy, University of Melbourne, Melbourne, Victoria, Australia.
Arch Phys Med Rehabil. 2001 Feb;82(2):183-9. doi: 10.1053/apmr.2001.19022.
To determine whether electromyographic (EMG) onsets of vastus medialis obliquus (VMO) and vastus lateralis (VL) are altered in the presence of patellofemoral pain syndrome (PFPS) during the functional task of stair stepping.
Cross-sectional.
University laboratory.
Thirty-three subjects with PFPS and 33 asymptomatic controls.
Subjects ascended and descended a set of stairs-2 steps, each 20-cm high-at usual stair-stepping pace. EMG readings of VMO and VL taken on middle stair during step up (concentric contraction) and step down (eccentric contraction).
Relative difference in onset of surface EMG activity of VMO compared with VL during a stair-stepping task. EMG onsets were determined by using a computer algorithm and were verified visually.
In the PFPS population, the EMG onset of VL occurred before that of VMO in both the step up and step down phases of the stair-stepping task (p <.05). In contrast, no such differences occurred in the onsets of EMG activity of VMO and VL in either phase of the task for the control subjects.
This finding supports the hypothesized relationship between changes in the timing of activity of the vastimuscles and PFPS. This finding provides theoretical rationale to support physiotherapy treatment commonly used in the management of PFPS.
确定在上下楼梯这一功能性任务中，髌股疼痛综合征（PFPS）患者的股内侧斜肌（VMO）和股外侧肌（VL）的肌电图（EMG）起始时间是否发生改变。
横断面研究。
大学实验室。
33例PFPS患者和33名无症状对照者。
受试者以平常上下楼梯的步伐上下一组楼梯——共2级台阶，每级台阶高20厘米。在迈上（向心收缩）和迈下（离心收缩）楼梯过程中，于楼梯中间位置采集VMO和VL的肌电图读数。
上下楼梯任务期间，VMO与VL表面肌电活动起始时间的相对差异。肌电图起始时间通过计算机算法确定，并经肉眼验证。
在PFPS患者群体中，在上下楼梯任务的迈上和迈下阶段，VL的肌电图起始时间均早于VMO（p<.05）。相比之下，在该任务的任一阶段，对照组受试者VMO和VL的肌电活动起始时间均无此类差异。
这一发现支持了股部肌肉活动时间变化与PFPS之间的假设关系。这一发现为支持PFPS管理中常用的物理治疗提供了理论依据。
