Flexion - Extension

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Flexion There is limited amount of motion in the thoracic region due to stability of the trunk, but there is still some motion occurring. The reason for limited motion in the thoracic spine is due to the attachment of the ribs on the thoracic vertebrae themselves along with small and rigid vertebral discs. The most thoracic flexion (bending forward) occurs in the lower thoracic spine because the vertebrae start to orient their facets similar to the lumbar spine where the most flexion and extension occurs. Also the lower thoracic spine is not as cemented in place by the floating ribs.
Range of motion: 30-40°

Extension Beside returning to the neutral position from a flexed position, thoracic extension (bending backward) is practically inexistant.
Range of motion: 0°

Thoracic Rotation

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Thoracic rotation refers to the rotary movement of the spine on the transverse plane. Each vertebra is capable of moving in three directions (back and forth, lateral flexion, and rotation), and even though the movement at each joint is small, the spine as a single structure has great flexibility and range of motion.
Range of motion:  30°   It is difficult to separate from the lumbar rotation (RoM of 15°) which together will produce a rotation of around 45° of the shoulder relative to the pelvis.


Image result for lumbar flexion muscles

Thoracic flexion: Rectus Abdominis, Internal Obliques, External Obliques.
Thoracic extension:  Longissimus Thoracis, Iliocostalis Thoracis, Spinalis Thoracis, Semispinalis Thoracis, Rotatores Thoracis.
Thoracic rotation:  Internal Obliques, External Obliques, Iliocostalis, Multifidus, Rotatores.

Evaluating Movement Dysfunction

Mobility tests: Thorax
Strength tests: Thorax Thoracic and Lumbar spine strength are considered together here.
Posture evaluation: Look for poor alignments in all planes.
FMS: Trunk Stability, trunk should remain stable and straight.
           Rotary Stability: spine should be mobile enough to avoid influencing balance.

Thoracic Rotation

Image result for running with excessive trunk rotation

Trunk torsion while running will reduce performance in sprinting, and increase the risks of injuries.
The rotation of the hips and counter rotation of the thorax should be limited to a few degrees.  Tension will be present to stabilize the trunk but should not result in separation between pelvis and shoulders.
Corrective measures
      Strength: All Thorax Strength exercises.

Image result for shoulder hip separation in javelin throw

Shoulder-hip separation for throws is a good thing (as per photo).  Hips are first rotated while the shoulders are kept back creating a torsion of the trunk, the separation shoulder-hip.  This allows more time to the trunk to accelerate the shoulders and the implement.  The lack of separation might be caused by a lack of mobility of the spine (either or both lumbar and thoracic).
Corrective measures
      Mobility: Seated Spinal Twist,    Laying Thoracis Spine Rotation