Reliability and effects of arm dominance on upper extremity isokinetic force, work, and power using the closed chain rider system.

OBJECTIVE

The purpose of our study was to assess the reliability of the Closed Chain Rider System between exercise sessions and to determine the effects of arm dominance using muscle force, work, and power measures during closed chain chest-press exercise.

DESIGN AND SETTING

Sitting subjects underwent identical testing on 2 occasions and performed 5 reciprocal chest-press movements at speeds of 51 and 76 cm/s.

SUBJECTS

Thirty-eight healthy college students.

MEASUREMENTS

Average force, total work, average power, and linear range of motion were recorded. Reliability was evaluated by calculating intraclass correlation coefficients. Mean differences between the dominant and nondominant arms for the measured variables were analyzed by dependent t tests.

RESULTS

For both the dominant and nondominant arms at the 51 and 76 cm/s speeds, reliabilities of average force (range = 0.85 to 0.91), total work (range = 0.88 to 0.92), and average power (range = 0.86 to 0.89) were clinically acceptable. The dominant arm produced significantly greater average force, total work, and average power compared with the nondominant arm.

CONCLUSIONS

Our results provide clinically useful information about the reliability of force, work, and power measures during multijoint bilateral chest-press movement. Clinicians should be aware of measured differences between dominant and nondominant arms.