Thoracic spine extension mobility in young adults: influence of subject position and spinal curvature.

Study Design: Cross-sectional study.

Objectives: To examine extension mobility of the thoracic spine in young, asymptomatic adults, with particular reference to the influence of subject position and magnitude of the thoracic kyphosis.

Background: Impairment of thoracic extension motion is commonly associated with mechanical pain disorders in this region of the spine.