Affiliations: University of Miami, Division of Physical Therapy, Steven J. Rose Laboratory, Coral Gables, FL 33146, USA
Correspondence:
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Correspondence to: Penny G. Kroll, PhD, PT, Division of Physical Therapy, 5915 Ponce de Leon Blvd., Plumer Bldg. 5th Floor, Coral Gables, Fl 33146, USA. Tel.: +1 305 284 4535; Fax: +1 305 284 6128; E-mail: pkroll@miami.edu.
Abstract: The purpose of this study was to determine the relationship between five common methods of measuring isometric trunk strength and endurance: Isometric flexion and extension tests, an upright lifting task, and timed isometric flexion and extension endurance tests. Fifty-six healthy individuals (aged 18–65 years) with no history of back problems or disease volunteered for this study. Data were analyzed using a Pearson Product Moment Correlation Coefficient and Student’s T-test. Significant relationships (p<0.0001) were found between the B-200 isometric extension and upright pull (r=0.75); B-200 isometric flexion and upright pull (r=0.78); and B-200 isometric flexion and B-200 isometric extension (r=0.80). Men demonstrated greater strength than women in B-200 isometric flexion and extension, as well as in the upright pull measures (p<0.05). A variety of measures are frequently used to evaluate trunk “strength” in force production and endurance. Although strong correlation was observed among measures of force, no significant relationships were demonstrated between endurance and force measures. This suggests that a subject who demonstrates a strong performance on strength test of force may not necessarily display an equally strong performance on a strength test of endurance. Hence, to obtain a full picture of a person’s performance capabilities, measures of both force and endurance should be incorporated into evaluation protocols.
