The Affect of Muscle Fatigue on EMG Levels of the Biceps Brachii, Triceps Brachii, and Middle Deltoid
Hannah B. Roth
Dr. Michael Bird, Faculty Mentor
Electromyography (EMG) levels reflect the number of active muscle fibers or the rate at which muscle fibers are firing. The purpose of this study was to examine how fatigue of the biceps brachii, triceps brachii, and middle deltoid affects EMG levels. Fifteen subjects performed bicep curls, tricep extensions, and lateral raises to fatigue using free weights at 65%-85% of each subject’s 1-RM. EMG was measured at 1000Hz with Coulbourn Instruments Bioamplifiers. Raw data was rectified and integrated over 100 ms time intervals. The mean integrated EMG values increased from earlier repetitions to the later repetitions in all three lifts. An increase in muscle fiber recruitment and/or an increase in muscle fiber firing as muscles fatigue may contribute to the increase in EMG levels. These results further support strength training programs that utilize repetitions to fatigue as the technique for strength gains.
Keywords: EMG, muscle Fatigue
Topic(s):Exercise Science
Presentation Type: Oral Paper
Session: 34-3
Location: VH 1000
Time: 2:45