Anatomy and Biomechanics Of Thoracic Spine by Gagan.pptx

“This presentation provides a detailed overview of the anatomy and biomechanics of the thoracic spine. It covers vertebral structure, articulations, ligaments, and muscular attachments, along with key biomechanical principles governing thoracic spine motion. flexion, extension, lateral flexion, rotation)".

1. Anatomy and Biomechanics Of Thoracic Vertebrae BY GAGAN MPT IN CARDIOPULMONARY 1 st YEAR STUDENT

2. ANATOMY OF THORACIC VERTEBRAE There are 12 Thoracic Vertebrae that makes up posterior portion of thoracic cage. 2 nd to 8 th thoracic vertebrae are typical , and remaining are atypical thoracic vertebrae five in numbers i.e. 1 st ,9 th ,10 th ,11 th ,12 th . One of the unique aspects of the typical vertebrae is that the vertebral body and transverse processes have 6 costal articular surfaces , four on the body (a superior and an inferior costovertebral facet , demi-facet , on each side and one costotransverse facet on each of the two transverse process . The posterior located head of each ribs articulates with contiguous thoracic vertebral bodies , whereas the costal tubercles of ribs 1 to 10 articulates with transverse process of thoracic vertebrae.

3. Ligaments of thoracic region Ligaments of thoracic spine Actions Anterior longitudinal ligament Limits extension Posterior longitudinal ligament Limits flexion Ligamentum flavum Limits and soften end range intervertebral flexion Supraspinous ligaments Limits flexion Intraspinous ligament By restricting the saparation of spinous process, it limits excessive flexion and also stabilizes the joints. Radiate ligament of head Stabilize the costovertebral joints Intra-articular ligament of head Provide stability and limit excessive motion by resisting excessive rotation and gliding motion witin thoracic spine. Superior costotransverse ligament Stabilize the costotransverse ligament

4. LIGAMENTS IN THORACIC SPINE

5. Muscles at Dorsal aspects of thoracic spine Iliocostalis lumborum Iliocostalis thoracic Iliocostalis cervicis Longissimus thoracis Longissimus cervicis Longissmus capitis Spinalis thoracic Spinalis cervicis Spinalis capitis Semispinalis thoracis Semispinalis cervicis Semispinalis capitis Multifidus rotators

6. Spinal nerves originate from Thoracic spine

7. Thoracic Cage Anterior view Lateral view Posterior view

8. Joints formed at thoracic cage

9. Joints formed at thoracic cage

10. Muscles found at anterior surface of costal region

11. Respiratory muscles of inspiration Muscle of inspiration Action Innervation Diaphragm Dome of the contracting diaphragm lowers and flattens during inspiration. Phrenic nerve (C3- C5) Scalene It increases Intrathoracic volume by elevating the ribs and sternum. Ventral rami of spinal nerve roots (C3- C7) Intercostals It increase intrathoracic volume by elevating ribs. Intercostal nerves(T2 –T12)

12. Respiratory muscles of expiration Expiratory muscles Action Innervation Abdominal muscles Decrease intrathoracic volumes Compress the abdominal wall and contents which increase intraabdominal pressure. Intercostal nerve (T7-L1) Trasversus thoracis Depresses the ribs and pulling them inward Adjacent intercostal nerves Intercostales interni Depresses intrathoracic volume by depressing the ribs. Intercostal nerves(T2 – T12)

13. Kinematics of Thoracic spine

14. Kinematics of Thoracic spine

15. Osteokinematics Zygapophyseal facets lie in the frontal plane from T1 – T6 and therefore limit flexion and Extension in this region. The articular facets in lower thoracis region are oriented more in the sagittal plane and thus permitted some what more flexion and extension . The ribs and costal joints restrict lateral flexion in the upper and middle thoracic region, but in the lower thoracic segments, lateral flexion and rotation are relatively free because these segments are not limited by the ribs .

16. Arthrokinematics In flexion , the body of the superior vertebrae tilts anteriorly , translates anteriorly and rotates slightly on adjacent inferior vertebrae. At the zygapophyseal joints, the inferior articular facets of the superior vertebrae slides upward on the superior articular facets of the adjacent inferior vertebrae. In Extension , the opposite motion occurs ,the superior vertebrae tilt and translates posteriorly and the inferior articular facets glide downwards on the superior articular facets of the adjacent vertebrae .

17. Arthrokinematics In lateral flexion to right, the right inferior articular facets of the superior vertebrae downsloping (Inferior/Anterior Glide) on the right superior articular facets of the inferior vertebrae. On the contralateral side, the left inferior articular facets of the superior vertebrae upsloping (Superior/Posterior Glide) on the left superior articular facet of the adjacent inferior vertebra.

18. Arthrokinematics In axial rotation, the superior vertebra rotates on the inferior vertebra , and on the inferior articular surface of the adjacent vertebra. Rotation and gliding movements occurs between the ribs and vertebral bodies at the costovertebral joints .

19. Osteokinematics of Thoracic Cage “ Pump handle motion ” During inhalation Occurs predominantly in the sagittal plane. Elevates the ribcage and sternum. Most movement occurs anteriorly Costocartilage rotates upward, becoming more horizontal with inspiration. The movements of the ribs pushes the sternum ventrally and superiorly. Increases the anterior-posterior diameter of the thorax. Ribs : elevate with a slight rotation. Sternum: Elevation ; Superior and anterior movement Vertebrae: No, movement during this movement.

20. “Bucket handle motion” During inhalation Elevation of ribs Occurs about an axis of motion lying more toward sagittal plane. Lower ribs have a more angled shape, allowing for more motion at the lateral aspect of the ribcage. Increase the transverse diameter of the ribcage. Each ribs, during this movements , elevates and also has a slight rotation during inhalation. Vertebrae and sternum have relatively no movement in this motion.

21. Arthrokinematics of thoracic cage

22. When the costal ribs and sternal antero-posterior diameter increases during inhalation, at the costotransverse joint rotation occurs superiorly and downward translation takes place. When the costal ribs and sternal antero-posterior diameter decreases during exhalation , at the costotransverse joint rotation occurs inferiorly and upward translation takes place.

23. Clinical Pathology of thoracic spine “Scoliosis” Sometimes the body ossifies from two primary centres , and if one centre fails to develop, one half, right or left of the body is missing. This results in a hemivertebra and lateral bend in the vertebral column or scoliosis. “Prolapse Intervertebral disc” Disc prolapse is usually posterolateral. The prolapsed nucleus pulposus presses upon adjacent nerve roots and gives rise to pain that radiates along the distribution of the nerve. Such pain along the course of the sciatic nerve is called sciatica . Motor effects, with loss of power and reflexes, may follow. Disc prolapse occurs most frequently in the lower lumbar region. It is also common in the lower cervical region from fifth to seventh cervical vertebrae

24. Thoracic cage clinical anatomy “Pectus excavatum” (Funnel chest) is posterior displacement of sternum and costal cartilage due to overgrowth of costal cartilage. Most common chest deformity. 3:1 Male female ratio. 1 ST and 2 nd ribs and manubrium are in normal position. Assymetry of ribs may be present and often right side is more depressed the left.

25. “Pectus carinatum” is second chest wall deformity found in children. It is the birth defects in which chest is protrude over the sternum and in some cases it is not even noticeable. Male female ratio is 4:1. Mild deformity at birth and it worses as child grows.

26. References – Bd Chaurasia Anatomy Kinesiology by Donald A. Neumann Kinesiology by Cynthia Norkin Videos and images references - Medicos physio Anatomy 3d Biology students

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