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Assessment of Closed Kinetic Chain Isokinetic Testing of Upper Extremity Average Power Production
Authors: Sarah E. Davis, Kevin D. Huet, Bryan L. Riemann, George J. Davies
Armstrong Atlantic State University, Savannah, GA.
There is a need to establish a reliable standard for testing upper extremity power (UEP). Isolated open kinetic chain isokinetic testing, which has demonstrated excellent validity and reliability, is commonly used to quantify average power (AP). Little is known about closed kinetic chain (CKC) isokinetic testing of the upper extremity (UE).
PURPOSE: To determine isokinetic UE CKC reliability and compare AP between sexes and limbs at 120°•s-1, 210°•s-1, and 300°•s-1.
METHODS: 24 physically active (PA) men (n=12, 24.1 + 1.7 yrs, 1.8 + 0.1 m, 83.2 + 12.7 kg) and women (n=12, 23.3 + 2.0 yrs, 1.6 + 0.1 m, 64.9 + 10.1 kg) completed a test re-test (>96 hours) paradigm to establish isokinetic UE CKC reliability of AP production. Following warm-up, subjects completed five maximal press and pull repetitions on the Biodex© System III Dynamometer (Biodex, Inc., Shirley, NY). Both limb and speed order were randomized between subjects.
RESULTS: High relative reliability using intraclass correlation coefficients (2, k) were revealed for AP (range: 0.919-0.985) across speeds, limbs and direction. The men demonstrated significantly greater AP than the women for both directions across all speeds. There were no significant differences for press (P=.712 to 1) and pull (P=.934 to 1) AP between the three speeds in the women. In contrast, the men demonstrated significantly greater press AP at 300°•s-1 compared to 210°•s-1 (P=.004, 95% CIdiff: 25.5 to 145.3 W) and 210°•s-1 compared to 120°•s-1 (P<.001, 95% CIdiff: 126.5 to 302.3 W). Similarly, the men demonstrated significantly greater pull AP at 300°•s-1 compared to 210°•s-1 (P<.001, 95% CIdiff: 53.7 to 138.1 W), and 210°•s-1 compared to 120°•s-1 (P<.001, 95% CIdiff: 50.0 to 177.5 W).
CONCLUSION: Isokinetic CKC testing for UEP is a reliable technique. We attribute the speed differences for the men but not the women to specificity of training. PA men are more likely to perform bouts of resistance training compared to PA women. Unexpectedly, there were no AP differences between dominant and nondominant limbs. We attribute this to the unique motor pattern of isokinetic UE CKC testing. We speculate the press and pull motions are typically performed bilaterally with most functional activities.