Reliability of electromyography parameters during stair deambulation in patellofemoral pain syndrome

Reliability is essential to all aspects of the measure, as it shows the quality of the information and allows rational conclusions with regard to the data. There has been controversial results regarding the reliability of electromyographic parameters assessed during stair ascent and descent in individuals with patellofemoral pain syndrome (PFPS). Therefore, this study aims to determine the reliability of time and frequency domain electromyographic parameters on both gestures in women with PFPS. Thirty-one women with PFPS were selected to participate in this study. Data from vastus lateralis and medialis were collected during stair deambulation. The selected parameters were: automatic onset, median frequency bands of low, medium and high frequency. Reliability was determined by intraclass correlation coefficient and the standard error of measurement. The frequency domain variables have shown good reliability, with the stair ascent presenting the best rates. On the other hand, onset has proved to be inconsistent in all measures. Our findings suggest that stair ascent is more reliable than stair descent to evaluate subjects with PFPS in the most cases.

信度对于测评的各维度均具有重要意义，其既可体现信息的质量，也可为基于数据的合理推断提供支撑。针对髌股疼痛综合征（patellofemoral pain syndrome, PFPS）患者在楼梯上行与下行过程中所测评的肌电参数（electromyographic parameters）信度，既往研究结论尚存争议。因此，本研究旨在探究髌股疼痛综合征女性患者在上述两种动作模式下，其时域（time domain）与频域（frequency domain）肌电参数的信度。本研究共招募31名确诊髌股疼痛综合征的女性受试者。采集受试者股外侧肌与股内侧肌在楼梯步行过程中的肌电数据，所选测评参数包括：肌电自动启动时刻、低/中/高频段的中位频率。信度分析采用组内相关系数（intraclass correlation coefficient）与测量标准误（standard error of measurement）进行评估。结果显示，频域变量具有良好的信度，其中楼梯上行的信度表现最优。与之相反，肌电启动时刻在所有测评中均表现出较差的一致性。本研究结果表明，在多数情况下，相较于楼梯下行，楼梯上行更适合用于评估髌股疼痛综合征受试者的肌电参数。