The purpose of this study was to assess the reliability of the Closed Chain Rider System (Mettler Electronics) between exercise sessions and to determine the effects of limb dominance using muscle force and work measures during closed chain leg press exercise. Thirty-nine recreationally active college students underwent identical testing on two occasions, during which each subject performed five reciprocal leg press movements at speeds of 10, 15, and 20 in./s while seated. Average force, total work, and linear range of motion were recorded. Reliability values for average force and work were clinically acceptable for the dominant and nondominant limbs. The dominant limb produced greater average force and total work versus the nondominant limb, and average linear ROM was similar between the dominant and nondominant limbs. Differences in the torque and work values observed suggest that the clinician must be aware of differences between the dominant and nondominant limbs when used for comparative purposes.
John E. Kovaleski, Robert J. Heitman, Larry R. Gurchiek, Joel W. Erdmann and Terry L. Trundle
John E. Kovaleski, Robert J. Heitman, Damon P.S. Andrew, Larry R. Gurchiek and Albert W. Pearsall IV
Isokinetic strength and functional performance are used to assess recovery after rehabilitation. It is not known whether low-speed closed-linear-kinetic isokinetic muscle strength correlates with functional performance.
To investigate the relationship between linear closed (CKC) and open (OKC) concentric isokinetic strength of the dominant lower-limb extensors and functional performance.
Thirty uninjured men and women (age = 20.9 ± 2.4 years).
Main Outcome Measures:
Peak CKC and OKC isokinetic strength and best score from a shuttle run for time, single-leg vertical jump, and single-leg hop for distance.
Neither lower-limb CKC nor OKC isokinetic strength measured at low speeds correlated highly with performance on the functional tasks of jumping, hopping, and speed/agility.
Although the basis of both closed and open isokinetic strength must be appreciated, they should not be the only determinants of functional performance.