title: Whole-body-vibration-induced increase in leg muscle activity during different squat exercises.
abstract: This study analyzed leg muscle activity during whole-body vibration (WBV) training. Subjects performed standard unloaded isometric exercises on a vibrating platform (Power Plate): high squat (HS), low squat (LS), and 1-legged squat (OL). Muscle activity of the rectus femoris, vastus lateralis, vastus medialis, and gastrocnemius was recorded in 15 men (age 21.2 +/- 0.8 years) through use of surface electromyography (EMG). The exercises were performed in 2 conditions: with WBV and without (control [CO]) a vibratory stimulus of 35 Hz. Muscle activation during WBV was compared with CO and with muscle activation during isolated maximal voluntary contractions (MVCs). Whole-body vibration resulted in a significantly higher (p < 0.05) EMG root-mean-square compared with CO in all muscle groups and all exercises (between +39.9 +/- 17.5% and +360.6 +/- 57.5%). The increase in muscle activity caused by WBV was significantly higher (p < 0.05) in OL compared with HS and LS. In conclusion, WBV resulted in an increased activation of the leg muscles. During WBV, leg muscle activity varied between 12.6 and 82.4% of MVC values.
authors.affiliation: Exercise Physiology and Biomechanics Laboratory.
authors.forename: Machteld
authors.initials: M
authors.lastname: Roelants
authors.forename: Sabine M P
authors.initials: SM
authors.lastname: Verschueren
authors.forename: Christophe
authors.initials: C
authors.lastname: Delecluse
authors.forename: Oron
authors.initials: O
authors.lastname: Levin
authors.forename: Valère
authors.initials: V
authors.lastname: Stijnen
mesh_terms: D000328:Adult; D004576:Electromyography; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D014732:Vibration