The effects of PETTLEP imagery and action observation on strength performance of a leg extension and flexion task

Research suggests that imagery can be enhanced by incorporating action observation into theoretically based imagery interventions. The purpose of the study was to investigate the effects of PETTLEP imagery intervention on strength performance. All individuals completed the Mental Imagery Questionnaire-III and were tested on peak force production with the quadriceps and hamstrings using the Biodex dynamometer. Participants were randomly placed into imagery with action observation (IAO), physical practice (PP), or control (CON) groups for a five-week intervention. Following post-testing, individuals completed the Intrinsic Motivation Inventory (IMI). Both PP and IAO significantly improved in isometric quadriceps peak force production when compared to CON (p<0.05). Additionally, PP significantly increased peak force production during isokinetic testing with the quadriceps (p<0.05). No significant changes were observed in the hamstrings (p>0.05). No group differences were found in IMI scores (p>0.05). The practical and theoretical implications for this research are discussed.