At the conclusion of this chapter, the reader will be able to:
Identify the key anatomical and biomechanical features of the thoracic spine and costal cage and their impact on examination and intervention.
List and perform key procedures used in the orthopaedic manual physical therapy (OMPT) examination of the thoracic spine and costal cage.
Demonstrate sound clinical decision-making in evaluating the results of the OMPT examination.
Use pertinent examination findings to reach a differential diagnosis and prognosis.
Discuss issues related to the safe performance of OMPT interventions for the thoracic spine and costal cage.
Demonstrate basic competence in the performance of a skill set of joint mobilization techniques for the thoracic spine and costal cage.
FUNCTIONAL ANATOMY AND KINEMATICS
The thoracic spine and its associated costal cage is comprised of 12 vertebrae and 12 paired costal segments and is sometimes referred to collectively as the thorax. The thoracic spine is mechanically stiffer and less mobile than either the cervical or lumbar regions and, therefore, a less common cause of spine-related impairment. The relative reduction in mobility that is characteristic of this region is related to the orientation of the thoracic articular processes, the ratio between intervertebral disc height and vertebral body height, and the intimate relationship that the thoracic spine shares with the costal cage. The thoracic spine and associated costal cage provide rigid support and protection for the vital organs that lie beneath. This structure also provides a stable foundation that facilitates optimal function of the diaphragm during respiration. Impairment of the thorax, therefore, may impact not only the musculoskeletal system, but, by virtue of its functional demands, may also influence the respiratory, nervous, and circulatory systems as well. The 12 segments of the thoracic spine are configured to create a posterior convexity in the sagittal plane, known as kyphosis. This kyphosis is referred to as the primary spinal curve since it is the first to develop in utero. It serves to counterbalance the lordotic curves that are present in both the cervical and lumbar regions. Although less mobile than the remainder of the spine, the upper thoracic (T1-T4) and lower thoracic (T9-T12) segments often resemble adjacent spinal regions and possess an inclination toward greater degrees of mobility. The cervicothoracic and thoracolumbar regions are referred to as transitional vertebrae and have important clinical implications for the manual physical therapist.
The kyphotic arrangement of the thoracic spine is due largely to the shape of the vertebral bodies, which possess greater height posteriorly. The magnitude of this posterior convexity increases with age and often becomes pathological primarily in older, postmenopausal females with osteoporosis, sometimes resulting in compression fractures of the vertebral body from relatively benign forces. The vertebral bodies of the thoracic spine are wider when measured anterior-posteriorly than medial-laterally and increase in size and density as ...