Abstract
OBJECTIVE: Although many clinicians believe high growth leads to inflexibility, which may lead to lower extremity pain, the only prospective data suggest growth is unrelated to flexibility. However, it is still possible that growth and/or flexibility are related to pain even if they are not related to each other. We investigated the incidence of leg pain in adolescents to determine whether high growth spurt and/or poor flexibility are risk factors for the development of lower extremity pain. METHODS: Repeated measures, prospective cohort study of urban high school students aged 12-18. Subjects were measured at baseline and at 6 and 12 months for flexibility of hamstrings and quadriceps and with the sit-and-reach test. Participants completed a detailed questionnaire on recreational activity, occupational activities, psychosocial variables, and musculoskeletal pain. RESULTS: Poor hamstring flexibility (odds ratio 0.99, confidence interval 0.97-1.01), poor quadriceps flexibility (OR 1.01, CI 0.99-1.03), poor sit-and-reach flexibility (OR 0.99, CI 0.99-1.01), and growth (OR 0.93, CI 0.50-1.71) were not related to the development of lower extremity pain. There was an association between lower extremity pain and occupational activities (OR 2.08, CI 1.45-2.98) and poor mental health (per 1 SD change, OR 1.41, CI 1.19-1.67). CONCLUSION: Neither growth nor flexibility is related to the development of lower extremity pain in adolescents. A poor mental health score and occupational activities may be associated with the development of lower extremity pain.