Search tips
Search criteria 


Logo of jathtrainLink to Publisher's site
J Athl Train. 1993 Summer; 28(2): 106-107, 110-111.
PMCID: PMC1317693

Concentric Isokinetic Trunk Extension/Flexion Testing of Rigid and Semirigid Lumbar/Sacral Supports

M.L. Woodhouse, PhD, ATC
M.L. Woodhouse is Director at Exercise Science Laboratory, Norfolk State University, Norfolk, VA 23507, Associate Research Professor at Department of Orthopaedics, Eastern Virginia Medical School, Norfolk, VA 23507.
James R.K. Heinen, PhD
James R.K. Heinen is Associate Professor at College of Education, Old Dominion University, Norfolk, VA.
Lawrence Shall, MD
Lawrence Shall is Associate Professor at Department of Orthopaedics, Eastern Virginia Medical School, Norfolk, VA.


Using a Cybex® trunk extension/flexion device, we measured the effects of rigid and semirigid lumbar/sacral supports on peak muscular torque, total work, and average power. Ten well-conditioned men, aged 21 to 35, performed three testing sessions each at 7-day intervals (one session with a rigid support, one session with a semirigid support, and one with no support). We selected four isokinetic testing speeds (30°/s, 60°/s, 90°/s, and 120°/s), complying with a standard Cybex trunk extension/flexion protocol. Differences between lumbar/sacral supports were analyzed using an analysis of variance (ANOVA) and Scheffé post hoc tests. Peak torque, total work, and average power were significantly different (p<.05) during trunk flexion at various isokinetic velocities. Trunk extension movements did not appear to be affected by the use of supports, but trunk flexion was significantly greater with the semirigid device and with no device than with the rigid support. We concluded that a rigid lumbar/sacral support decreases strength during movement tasks involving trunk flexion with resistance.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.2M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Harman EA, Rosenstein RM, Frykman PN, Nigro GA. Effects of a belt on intra-abdominal pressure during weight lifting. Med Sci Sports Exerc. 1989 Apr;21(2):186–190. [PubMed]
  • Harman EA, Frykman PN, Clagett ER, Kraemer WJ. Intra-abdominal and intra-thoracic pressures during lifting and jumping. Med Sci Sports Exerc. 1988 Apr;20(2):195–201. [PubMed]
  • Langrana NA, Lee CK. Isokinetic evaluation of trunk muscles. Spine (Phila Pa 1976) 1984 Mar;9(2):171–175. [PubMed]
  • Langrana NA, Lee CK, Alexander H, Mayott CW. Quantitative assessment of back strength using isokinetic testing. Spine (Phila Pa 1976) 1984 Apr;9(3):287–290. [PubMed]
  • Marras WS, King AI, Joynt RL. Measurement of loads on the lumbar spine under isometric and isokinetic conditions. Spine (Phila Pa 1976) 1984 Mar;9(2):176–187. [PubMed]
  • Troup JD, Leskinen TP, Stalhammar HR, Kuorinka IA. A comparison of intraabdominal pressure increases, hip torque, and lumbar vertebral compression in different lifting techniques. Hum Factors. 1983 Oct;25(5):517–525. [PubMed]

Articles from Journal of Athletic Training are provided here courtesy of National Athletic Trainers Association