title: The effects of imagery training on fast isometric knee extensor torque development.
abstract: We hypothesized that imagery training would improve the fast onset of neuromuscular activation and thereby fast knee extensor isometric torque development. Forty young healthy participants, not involved in strength training, were assigned to one of four groups: physical training, imagery training, placebo training or control. The three training groups had three 15 min sessions per week for 4 weeks, with a 90 ° knee angle but were tested also at 120 °. At 90 ° knee angle, maximal torque increased (-8%) similarly in all three training groups. The torque-time integral (contractile impulse) over the first 40 ms after torque onset (TTI40) increased (P < 0.05) after physical training (by -100%), but only at 90 °. This increase was significantly different from the delta values (change pre to post) in the control and placebo groups, whereas delta values in the imagery group were similar to those in the placebo group. The increases in TTI40 following physical training were related (r (2) = 0.81, P < 0.05) to significant increases of knee extensor rectified surface EMG at torque onset (EMG40). In conclusion, only physical training led to a knee angle specific increase of contractile impulse that was significantly different from placebo and controls and that was related to improved onset of neuromuscular activation.
authors: Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, Netherlands. c.j.de.ruiter@vu.nl
authors: Cornelis J
authors: CJ
authors: de Ruiter
authors: Vana
authors: V
authors: Hutter
authors: Chris
authors: C
authors: Icke
authors: Bart
authors: B
authors: Groen
authors: Anne
authors: A
authors: Gemmink
authors: Hiltsje
authors: H
authors: Smilde
authors: Arnold
authors: A
authors: de Haan
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D019018:Imagery, Psychotherapy; D007537:Isometric Contraction; D007717:Knee; D007719:Knee Joint / Q000502:physiology*; D035002:Lower Extremity; D008297:Male; D008606:Mental Processes; D053580:Muscle Strength; D018482:Muscle, Skeletal; D009424:Nervous System Physiological Phenomena; D010806:Physical Education and Training; D055070:Resistance Training; D019415:Torque; D055815:Young Adult