Low back pain (LBP) affects young and old. There is an upsurge in the report of LBP among adolescents. Low back pain presents itself as mechanical in a little percentage of the affected young population. It may linger into adulthood adding to the population that inevitably will have LBP in adult life. Low endurance of the back muscles is a precursor for LBP; especially recurrent/chronic LBP.The Biering Sorenson's test is a Static Muscular Endurance (BMSE) test. It is a simple clinical tool for assessment of low back muscular endurance. It is valid,reliable,safe,practical, responsive,easily administered and inexpensive. It is a useful tool in predicting susceptibility to LBP since it identifies back musculature with low endurance. It is therefore very important in the prevention and early treatment of LBP, which may forestall LBP in adult life. This study therefore established reference data and pattern of back extensor endurance in school-aged adolescents with and without LBP from Nigeria.