BACK MUSCLES' ENDURANCE IN ADOLESCENTS AND ADULTS: NORMATIVE DATA FOR A SUB-SAHARAN AFRICAN POPULATION

Abstract

Purpose: Back muscles' endurance assessment provides an objective indicator of the functional capacity of the back. This study sought to establish a gender and age referenced normative data for back muscles endurance for a Sub-Saharan African population. Methods: This cross sectional study involved 1253 (623 male, 630 female) consecutive participants between the ages of 11 and 69 years without a history of symptomatic LBP within one year to the time of the study. Participants were recruited from eight secondary schools, two universities and two teaching hospitals, respectively. All participants underwent assessment of the back extensor muscles' endurance using the modified Biering-Sorensen test of muscular endurance. The mean and percentile data for endurance time were determined for six gender/age groups classified on a range of 10 years. Results: The mean endurance time (ET) of all the participants was 119 ± 53.6 secs. Men exhibited a significantly (p = 0.001) higher ET than women (125.9 ± 53.3 versus 112.6 ± 53.1 secs). Using percentile values cut-points; poor endurance (less than 25th), moderate endurance (25–75th) and good endurance (> 75th percentile) were < 85.0 secs, 85–163 secs, and > 163 secs, respectively for male; and < 69.8 secs, 69.8–148 secs and > 148 secs, respectively for female. Conclusion: The normative values derived in this study would be useful in assessing impairment in back muscles' endurance in both healthy and patient populations. The results suggest that age, gender and anthropometric factors can significantly influence back muscles' endurance.