Allied Health Faculty Publications

The Mechanical and Clinical Reliability of the Kinetic Communicator's Gravity Correction Procedure

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Isokinetics and Exercise Science





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The purpose of this study was to determine the reliability of the Kinetic Communicator's (Kin-Com) gravity correction procedure. To determine mechanical reliability, gravity correction was performed at 11 different angles while weights (1.15, 2.30, 3.45 and 4.60 kg) were suspended from the lever arm. Intraclass correlation (ICC) between trials showed that the Kin-Com was able to gravity correct weights with high reliability (R = 0.961−0.999). Gravity correction values from the 11 angles were analyzed with a one-way analysis of variance with repeated measures to determine if differences existed between gravity correction values collected at different angles for each weight condition. Even though reliability was good for each angle, gravity correction values collected near the vertical position differed from the gravity correction values collected at the horizontal position (P < 05). Differences decreased as weight increased. To determine clinical reliability, 25 subjects (age = 21.0 years, height = 16.6 cm, weight = 59.8 kg) were also gravity corrected in both the seated and prone positions at six different angles on 2 separate days. Correlation analysis between days showed good reliability (R = 0.83) for both positions when subjects were corrected at the horizontal. Reliability decreased as the lever arm approached vertical. Differences between gravity correction values existed at every angle measured for both positions. Even though the gravity correction was shown to be reliable at positions other than the horizontal, gravity correction should be performed at the horizontal position each time subjects are assessed.


Gravity correction, reliability via positions