KNOWLEDGE AND IMAGERY OF CONTRACTILE MECHANISMS DO NOT IMPROVE MUSCLE STRENGTH

Improving performance in strength tasks requires modifications characteristic of motor skill learning, such as more efficacious motor-unit firing behavior. Because domain-specific knowledge is integral to learning and performing motor skills, the present purpose was to examine selected factors of strength-specific knowledge and effects they might have on acquiring strength. Following baseline testing for maximal strength on a knee-extension task, participants were matched by sex and strength and placed into control (n = 8) and treatment (n = 8) groups. Quadriceps muscle electromyographic data were also collected. The treatment group underwent two educational sessions detailing muscle physiology, neural control of muscle force, and imagery training using this knowledge. The control group underwent two educational sessions about health and fitness. Following the educational sessions the participants were retested for strength. Analysis indicated that the education and imagery treatment had no effect on strength, nor did electromyographic measures indicate that the treatment group benefitted from intervention. It was concluded that the knowledge was simply not relevant to knee extension-force production or that use of the knowledge involved a disadvantageous internal focus of attention away from relevant task demands.