Low back pain (LBP) in children has been related to a serious problem for longtime. Recent studies have shown that no specific LBP in such age is as important as in adulthood and prevalence could reach 50%. Despite this high prevalence, it seems to be neglected by the child, family and doctors. Such a high rate, leads us to insist on meticulous clinical evaluation. Evaluation needs to include the measurement of trunk muscle strength and endurance.

Our goals were to determine the prevalence of low back pain in children and adolescents, describe the characteristics of spine muscles endurance in children with LBP and showing the interest of muscles evaluation.

We conducted an analytical cross-sectional study about 444 students, 201 boys and 243 girls, with average age of 14.95 years. We conducted an analytical cross-sectional study about 444 students, 201 boys and 243 girls, with average age of 14.95 years. Evaluation includes anthropometric assessment, extensibility of sub pelvic muscles and the endurance of back muscles and quadriceps with spine examination.

The prevalence was 22.3%, 95% CI [18.2 to 26.2]. This prevalence increases with age with a marked female predominance. Muscles endurance was lower in the LBP group (P<0.001 Sorensen test). More weakness was identified in extensors muscles with high signification (Shirado/Sorensen P<0.001).

Low back pain in children and adolescents is a common symptom, multifactorial, which is responsible of limitations of school and leisure activities. Trunk Muscles weakness may be a consequence or a cause of pain. Surely, it leads to chronic pain. The study of muscles endurance is necessary for diagnosis, rehabilitation and survey.