What is the correct LOD when palpating thoracic vertebral flexion?

When palpating the thoracic vertebrae for flexion, the correct Line of Drive (LOD) is Posterior-Anterior (P-A) with an Inferior-Superior (I-S) component throughout.

This approach is based on the mechanics of thoracic flexion, where the vertebrae move anteriorly (forward) as the spine flexes. Palpating with a P-A direction allows the practitioner to assess and feel the motion of the vertebrae as they move. The I-S component reinforces the engagement of the vertebrae during flexion, as it accounts for the upward movement of the spinous processes relative to the body of the vertebrae due to flexion at the thoracic level.

In practical terms, this means that when examining the thoracic spine in flexion, one should apply pressure from the back of the vertebrae forward and slightly upward to accurately assess the range and quality of flexion through the motion palpation technique. This is essential for identifying any restrictions or abnormalities related to the biomechanical function of the thoracic spine.