Reliability of Surface Electromyography During Maximal Voluntary Isometric Contractions, Jump Landings, and Cutting

• Published in: Journal of strength and conditioning research 2010-04, Vol.24 (4), p.1131-1137
• Main Authors: Fauth, McKenzie L, Petushek, Erich J, Feldmann, Christina R, Hsu, Brittni E, Garceau, Luke R, Lutsch, Brittney N, Ebben, William P
• Format: Article
• Language: English
• Subjects: Acceleration; Cohort Studies; Electromyography - methods; Exercise Test - methods; Female; Humans; Isometric Contraction - physiology; Knee Joint - physiology; Male; Muscle Fatigue - physiology; Muscle Strength - physiology; Muscle, Skeletal - physiology; Muscular system; Physical Exertion - physiology; Quadriceps Muscle - physiology; R&D; Range of Motion, Articular - physiology; Reproducibility of Results; Research & development; Studies; Track and Field - physiology; Young Adult
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/JSC.0b013e3181cc2353

Fauth, ML, Petushek, EJ, Feldmann, CR, Hsu, BE, Garceau, LR, Lutsch, BN, and Ebben, WP. Reliability of surface electromyography during maximal voluntary isometric contractions, jump landings, and cutting. J Strength Cond Res 24(4)1131-1137, 2010-The reliability of electromyographic (EMG) data has been examined for isometric and slow dynamic tasks, but little is known about the repeatability of this data for ballistic movements. The purpose of this study was to examine the within-session, trial-to-trial reliability of a variety of quadriceps and hamstrings muscles during isometric and ballistic activities. Data were analyzed by way of intraclass correlation coefficients (ICC), intersubject coefficients of variation (CVinter), and intrasubject coefficients of variation (CVintra). Twenty-four subjects performed 3 repetitions each of 2 randomly ordered test exercises, including landing from a depth jump (J) and cutting after a 10-m sprint (C). Data were acquired and processed with root mean square EMG for the muscles assessed, and data were analyzed for each exercise using a repeated measures analysis of variance. Results revealed that all ICC values were greater than 0.80, with most values greater than 0.90, CVinter values ranged from 5.4% to 148.7%, and CVintra values ranged from 11.5% to 49.3%. This study indicates that EMG is a reliable method for assessing the reproducibility of both the quadriceps and hamstrings muscle activation during either isometric or ballistic exercises.