Research article - (2006)05, 400 - 406
The Influence of Body Position on Load Range During Isokinetic Knee Extension/Flexion
Brian W. Findley1, Lee E. Brown2,, Michael Whitehurst3, Tedd Keating4, Daniel P. Murray2, Lisa M. Gardner2
1Palm Beach Community College, Boca Raton, FL, USA
2California State University, Fullerton, Fullerton, CA, USA
3Florida Atlantic University, Davie, FL, USA
4Manhattan College, Bronx, NY, USA

Lee E. Brown
✉ Associate Professor, Strength and Conditioning, California State University, Fullerton, Department of Kinesiology, KHS 233, 800 N. State College Blvd., Fullerton, CA 92831, USA.
Email: leebrown@fullerton.edu
Received: 06-03-2006 -- Accepted: 09-07-2006
Published (online): 01-09-2006

ABSTRACT

Isokinetic range of motion (ROM) has three distinct phases: rate of velocity development (RVD), load range (LR), and deceleration (DCC). The purpose of this study was to determine if differences in isokinetic knee extension/flexion LR exist between body positions. Ten subjects (4 males and 6 females, age 29.3 ± 5.4 yrs, ht 1.71 ± 0.10 m, wt 71.9 ± 12.9 kg) volunteered to participate in the seated vs. prone investigation and nine different subjects (4 males and 5 females, age 29.5 ± 6.9 yrs, ht 1.72 ± 0.09 m, wt 69.0 ± 13.8 kg) volunteered to participate in the seated vs. supine study. Each subject completed 3 maximal reciprocal concentric/concentric repetitions of dominant knee extension/flexion on a Biodex System 2 isokinetic dynamometer at 60, 120, 180, 240 and 360 deg·sec-1 in the supine or prone and seated positions. Repeated measures ANOVA revealed that only seated flexion at 360 deg·sec-1 (57.6 ± 1.7 degrees) elicited significantly (p < 0.05) greater LR than prone (49.2 ± 2.8 degrees). No significant differences in LR extension or flexion existed at any velocity between the supine vs. seated positions. ANOVA also demonstrated differences between seated vs. prone torque, work and power at most velocities while there was no difference between seated vs. supine. LR is the only phase of an isokinetic repetition where quantifiable resistance is maintained and this data appears to support that it may not be position-dependent but position may alter traditional performance variables.

Key words: Rate of velocity development, acceleration, deceleration

Key Points
  • Load range is the constant velocity phase where torque is collected.
  • Load range has an inverse relationship with velocity.
  • Load range may not be position dependent for the knee extensors or flexors.








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