Isokinetic Scapular Muscle Performance in Young Elite Gymnasts

摘要

>Context: During gymnastic exercises, considerable force output is required in the shoulder girdle muscles. Isokinetic performance of the scapular muscles in young, elite gymnasts has not been examined.>Objective: To compare the isokinetic muscle performance of the scapular muscles between elite adolescent gymnasts and nonathletic adolescents to identify differences in strength, endurance, and muscle balance based on high-level sport participation.>Design: Single-session, repeated-measures design.>Setting: University human research laboratory.>Patients or Other Participants: Sixteen young, elite gymnasts and 26 age-matched nonathletic subjects participated in the study.>Intervention(s): Linear protraction-retraction movement in the scapular plane at 2 velocities (12.2 cm/s and 36.6 cm/s).>Main Outcome Measure(s): Isokinetic strength and endurance values, peak force/body mass, work/body mass, fatigue index (difference between the work performed in the first third and the last third of the test), and protraction to retraction strength ratios.>Results: Elite gymnasts demonstrated higher values for the protraction peak force/body mass than the control group demonstrated (P < .05), and they demonstrated higher protraction to retraction ratios on the nondominant side than on the dominant side (P < .05 at low velocity, P < .001 at high velocity). Work/body mass and fatigue index values were not statistically different between the groups. Side differences (P = .003) for retraction strength with lower protraction to retraction ratios (P < .001) were apparent in the gymnast group on the dominant side.>Conclusions: Scapular muscle performance in elite, young gymnasts is characterized by increased protraction strength and altered muscular balance around the scapula compared with nonathletic adolescents.