Adolescent growth is not associated with changes in flexibility

Objective: To determine whether adolescent growth is associated with a decr ease in flexibility. Design: Longitudinal cohort study of urban high school students. Main Outcome Measures: Flexibility of hamstring muscles (popliteal angle), quadriceps muscles (quadriceps angle), lumbar extensor muscles (Schober tes t), and combined lower extremity-trunk muscles (Sit and Reach test). Results: There was no relation between growth and changes in flexibility fo r the lumbar flexor muscles, hamstring muscles, or muscles involved in the Sit and Reach test. Although there was a slight decrease in flexibility of the quadriceps muscle with increases in growth, the very low r(adj)(2) valu e (0.01-0.06) strongly suggests that growth plays only a small role in dete rmining the flexibility of individuals. Conclusion: These results strongly suggest that growth is not a cause of de creased flexibility during the peripubescent period.