Biomechanics of Thoracic Vertebrae PDF

# بسم الله الرحمن الرحيم ## Thoracic Vertebrae - 8 typical - 4 Atypical (T1, T10, T11, T12) ### Superior and Inferior Demi Facet - Typical (T2 - T9) - Atypical (T1, T10, T11, T12) ### Full Costal Facet - Inferior demi facet of the T2 vertebrae connects to the 2nd rib - Superior demi facet of...

# بسم الله الرحمن الرحيم ## Thoracic Vertebrae - 8 typical - 4 Atypical (T1, T10, T11, T12) ### Superior and Inferior Demi Facet - Typical (T2 - T9) - Atypical (T1, T10, T11, T12) ### Full Costal Facet - Inferior demi facet of the T2 vertebrae connects to the 2nd rib - Superior demi facet of the first thoracic vertebrae (T1) connects to the 1st rib - Full costal facet of the T1 vertebrae connects to the 1st rib. - Inferior demi facet of the T9 vertebrae does not have a superior demi facet. The rib connects to the full costal facet - T10 has a full costal facet connecting to the 10th rib. - T11 has a full costal facet connecting to the 11th rib. - T12 has a full costal facet connecting to the 12th rib. ## Ribs | | True (1-7) | False (8-10) | Floating (11, 12): | |---|---|---|---| | **Posterior:** | Connect to thoracic body and transverse process | Connect to thoracic body and only transverse process | Connect to thoracic body only | | **Anterior:** | Connect direct to sternum | Indirect to sternum and connect to costal cartilage of above rib | Don't connect (floating) to sternum | ## Note - There is a joint between the head of rib and the thoracic body called **costovertebral joint** - There is a joint between the tubercle of rib and the thoracic transverse process called **costotransverse joint** ## Ligament's 1. **Radiate ligament:** connects head of rib to the demi facet and the level vertebrae they are on. 2. **Costotransverse ligament (Lateral):** connects head of rib to the transverse process and the level vertebrae they are on. 3. **Superior Costotransverse Ligament:** Connects the rib to the superior vertebrae transverse process. 4. **Intraarticular ligament of the head:** connects the head of the rib to the facet joint. 5. **Anterior Longitudinal ligament:** 6. **Posterior Longitudinal ligament** 7. **Supraspinaus Ligament:** connects the vertebrae spinous processes ## Facet Joint Orientation of Thoracic - Cervical: Natural Lordosis - Thoracic: Natural Kyphosis, between 40-45 degrees - **Sagittal plane:** The angle is measured from the sagittal plane - Shows a diagram of the thoracic vertebra with an arrow pointing to the 40-45 degree angle ## ROM - F/E (Sagittal plane) - Flexion: 30-40 degrees - Extension: 20-25 degrees - Total: 50-65 degrees - Axial Rotation: 30-35 degrees - Lateral Flexion: 25-30 degrees ## Thoracic Kinematics - **Flexion:** Tightness (tension) of the capsule of the apophyseal joints and supraspinous, posterior longitudinal ligaments and interspinous ligaments - **Extension:** Tightness (tension) of anterior longitudinal ligament. ## Thoracic Arthro-Kinematic | | Sagittal Plane | Horizontal Plane | Frontal Plane | |---|---|---|---| | **Flexion:** | Sliding of inferior facet (superior and anterior) | Axial Rotation: anterior translation (due to size and attachment of ribs)| Lateral Flexion: Limited, because of lumbar (and anterior translation) | | **Extension** | Sliding of inferior facet (inferior and posterior) | Posterior translation (ex: rotation to left) | Thoracic: Sliding (slight; less than lumber) | | **Left** | Posterior, Inferior | Anterior, Superior | | | **Right** | Anterior, Superior | Posterior, Inferior | | | **Note:** | * The inferior demi facet of the superior vertebra slides on the superior demi facet of the inferior vertebra. | | |