Endurance of low back musculature: normative data for adults.

Abstract

Lack of baseline values is a limitation in the quantification of physical performance testing of the low back muscles. The purpose of this study is to present an age and gender normative values for static back extensor muscles' endurance in adults. Five hundred and sixty one healthy adults aged between 19 to 67 years volunteered for this study. Endurance of the low back musculature was assessed using modified Biering-Sørensen test of Static Muscular Endurance. The mean, standard deviation, and percentile scores for endurance time were determined for five gender / age groups classified on a range of 10 years. The mean endurance time of all the participants was 113 ± 46 seconds. Men had higher mean endurance than women (t=3.309; p=0.001). Significant difference (F=32.702; p=0.001) was found in the endurance time across the age groups. There was an age and gender variation in the percentile values. The normative values demonstrate that a decrease in endurance time is expected with increasing age. The significant age and anthropometric differences across the age groups could contribute to the endurance differences. These values could be used to compare a patient's score at intake and also serve as clinical target for which subsequent testing after treatment, at discharge and/or follow up can be compared, providing an indication of change in endurance capacity over time.