Biomechanics

Question 1

THORACIC SIDE BENDING

Answer 1

In right side bending, the right inferior facet of the superior vertebrae glides inferolaterally and the left inferior facet glides superomedially.

Controversy exists as to whether thoracic rotation couples contralaterally or ipsilaterally during side bending.

Question 2

THORACIC ROTATION

Answer 2

Thoracic spine rotation is accompanied by slight translation of the superior motion segment to the contralateral side.

Question 3

THORACIC RESPIRATION

Answer 3

(Pump handle - upper ribs) anterior-posterior diameter of the thorax expands and the intercostal muscles contract, the ribs move through axes at costovertebral / costotransverse joints; anterior ends of the rib rise with the sternum.

(bucket handle - lower ribs) transverse diameter of the thorax expands and intercostal muscles contract, the ribs move laterally and superiorly.

Thoracic segments EXTEND during inspiration, and return to netural during expiration.