The interrelation of spinal curves, pelvic tilt and muscle lengths in the adolescent female.

Thoracic kyphosis, lumbar lordosis and pelvic tilt were measured in standing in one hundred and three adolescent females, using a specially designed inclinometer. Indices of the muscle lengths (abdominals, erector spinae, iliopsoas, gluteals, rectus femoris and hamstrings) were measured using inclinometry and goniometry and expressed as angles of joint position. Multiple regression analysis revealed that the index of erector spinae length was negatively correlated with lumbar lordosis (r = - 0.24, p < 0.05). The abdominal length index was positively correlated with lumbar lordosis (r = 0.209, p < 0.05), and the hamstring length index was negatively correlated with lordosis (r = - 0.213, p < 0.05). No muscle length index was significantly related to pelvic tilt. A negative association between the degree of thoracic kyphosis and the abdominal length index was found (r = -0.245, p < 0.05).