Hubley-Kozey, CherylRobbins, ShawnRutherford, DerekStanish, William2016-06-022016-06-022013Hubley-Kozey, C. L., Robbins, S. M., Rutherford, D. J., & Stanish, W. D. (2013). Reliability of surface electromyographic recordings during walking in individuals with knee osteoarthritis. Journal of Electromyography and Kinesiology, 23(2), 334-341.http://hdl.handle.net/10222/71783http://dx.doi.org/10.1016/j.jelekin.2012.12.002Thanks to Nick Hill and Gillian Hatfield-Murdock for their assistance with data collection and processing. The study sponsors had no involvement in the design, conduct of the study or manuscript preparation.To determine test–retest reliability of a surface electromyographic protocol designed to measure knee joint muscle activation during walking in individuals with knee osteoarthritis (OA). Twenty-one individuals with moderate medial compartment knee OA completed two gait data collections separated by approximately 1 month. Using a standardized protocol, surface electromyograms from rectus femoris plus lateral and medial sites for the gastrocnemii, vastii and hamstring muscles were recorded during walking. After full-wave rectification and low pass filtering, time and amplitude normalized (percent of maximum) waveforms were calculated. Principal component analysis (PP-scores) and co-contraction indices (CCI) were calculated from the waveforms. Intraclass correlation coefficients (ICC2,k) were calculated for PP-scores and CCI’s. No differences in walking speed, knee muscle strength and symptoms were found between visits (p > 0.05). The majority of PP-scores (17 of 21) and two of four CCIs demonstrated ICC2,k values greater than 0.81. Remaining PP-scores and CCIs had ICC2,k values between 0.61 and 0.80. The results support that reliable EMG characteristics can be captured from a moderate knee OA patient population using a standardized protocol.ElectromyographyKnee osteoarthritisGaitReliabilityPrincipal component analysisText