Affiliations: [a] St. Paul's Hospital, Vancouver, Canada, and Curtin University of Technology, Perth, Western Australia
Note: [*] Physiotherapy Department, St. Paul's Hospital, Vancouver, British Columbia, Canada.
Note: [**] Address reprint requests to Alison M. Hoens, Section Head-Outpatients, Physiotherapy Department, St. Paul's Hospital, 1081 Burrard Street, Vancouver, British Columbia, Canada V6Z 1Y6.
Note: [***] Curtin University of Technology, Perth, Western Australia.
Abstract: The isokinetic strength and endurance of the trunk extensors and flexors in 72 normal male and female subjects were evaluated concentrically from 25° of extension to 30° of flexion at angular velocities of 20, 40, and 60 deg/sec, on two occasions. Full range of motion (ROM) average torque (FRAT) and truncated ROM average torque (TRAD were calculated. The direct values and derived ratios were analyzed by repeated-measures analysis of variance and Pearson product moment correlations. Direct FRAT and TRAT measures, although highly correlated (r > 0.997), were significantly different (p = 0.000) at each of the three angular velocities. Derived agonist/antagonist ratios had slightly lower correlations (r > 0.980) and were significantly different from each other only at 40 and 60 deg/sec (p = 0.0001 and p = 0.0012). It was concluded that for measurements of isokinetic strength of TEs and TFs, the initial and terminal nonisokinetic phases should be truncated before calculating the average torque, unless the result is expressed as the agonist/antagonist ratio and the angular velocity of measurement is slow.
Keywords: Trunk extensor/flexor, trunk flexor/extensor, full range of motion average torque, truncated range of motion average torque
