STATIC ENDURANCE OF THE BACK EXTENSOR MUSCLES: ASSOCIATION BETWEEN PERFORMANCE AND REPORTED REASONS FOR TEST TERMINATION

Abstract

Purpose: Quite a few studies have reported previously on reasons for terminating tests of back muscles endurance. This study investigated the association between endurance performance and reported reasons for terminating back extensor muscle endurance test in apparently healthy adults. Methods: Three-hundred-and-seventy-six volunteers with the mean age of 38.9 ± 13.5 years participated in this study. All participants underwent modified Biering–Sørensen test of Static Muscular Endurance. Descriptive statistics of mean and standard deviation, Pearson's correlation and Chi-square, ANOVA and ANCOVA were used to analyze the data. The α level was set at 0.05. Results: It is found that 76.1% of the participants terminated the test due to fatigue in the low back, followed by low-back pain (LBP) (12.8%) and fatigue in the gluteal or hamstring muscles (7.4%) respectively. The magnitudes of the endurance time for each reason of termination — fatigue in the low back (121 ± 49.3 sec), fatigue in the gluteal or hamstring muscles (102 ± 44.0 sec), LBP (59 ± 27.4 sec), and behavioral factors (92 ± 34.7 sec) were found to be significantly different (p = 0.001). Test termination due to fatigue in the low back was on the average 62 seconds longer than that due to LBP. Conclusions: Fatigue was the most commonly reported reason for back extensor muscles' endurance test termination. Endurance time was least in those individuals who terminate the test due to complaints of LBP and greatest in those who end the task for fatigue only.