2a PT 0500 Trunk Arthrology.pdf

PT 500 Human Anatomy Arthrology of the Trunk 1. Arthrology of the Trunk a. Spinal Ligaments i. Anterior longitudinal ligament (ALL) 1. Extends from basilar occiput and anterior tubercle of...

PT 500 Human Anatomy Arthrology of the Trunk 1. Arthrology of the Trunk a. Spinal Ligaments i. Anterior longitudinal ligament (ALL) 1. Extends from basilar occiput and anterior tubercle of atlas to sacrum 2. Runs along anterior surface of vertebral bodies and discs (has attachments to both bodies and discs): thickest centrally, but extends to IVF 3. Becomes wider distally 4. Limits extension (only ligament to limit extension) ii. Posterior longitudinal ligament (PLL) 1. Runs from axis to sacrum 2. Attaches primarily to discs, some attachment to posterior aspect of vertebral bodies 3. Narrower and weaker than ALL, broadest in thoracic region 4. Continuous with tectorial membrane in upper cervical region 5. May limit flexion, limits posterior herniation of discs 6. Well innervated with pain receptors iii. Supraspinous ligament 1. Runs along the spinous processes from C7 to sacrum 2. Limits flexion iv. Ligamentum Nuchae 1. Continuation of supraspinous ligament in cervical region (C6 to occiput) 2. Blends with interspinous to hold neck in extension v. Interspinous ligament 1. Between adjacent spinous processes 2. Blends with interspinales muscles  helps hold space b/t vertebrae 3. Intertransverse ligament serves a similar role b/t transverse processes vi. Ligamentum flavum 1. Highly elastic (yellowish) fibers 2. Attaches from anterior surface of lamina above to posterior surface of lamina of segment below 3. Limit rapid flexion of spinal column 4. Thickest in lumbar region Section 1 1  b. Intervertebral Discs i. Overview of Discs 1. Account for 20-25% of spine length 2. Shock absorbers, help disperse forces 3. Provide strong attachments between vertebral bodies 4. Permits movement between vertebrae 5. Consists of the outer annulus fibrosus and the inner nucleus pulposus. 6. 80% water in younger individuals 7. Wider anteriorly in the lumbar and cervical regions helping to form the spinal curves (lordosis) ii. Anulus Fibrosis 1. Fibrous concentric rings of fibrocartilage around the circumference of the disc 2. Fibers in each lamella run obliquely at 60°-90° angles to stabilize during rotation, fibers run 30° off vertical to allow rotation b/t adjacent vertebral bodies 3. Outer 1/3 has sensory innervation; vascularization decreases as one moves centrally 4. Thicker anteriorly than posteriorly 5. Attach to hyaline cartilage (end plates) on the vertebral bodies 6. Also have attachments to the anterior and posterior longitudinal ligaments Section 1 2  iii. Nucleus Pulposis 1. Fibrogelatinous inner portion: approximately 80 - 88% water (higher in younger individuals, reduces with age) 2. Avascular (receives nutrition via diffusion) 3. Serves as a fulcrum during movement iv. Function 1. Distribute loads 2. Absorb shock 3. Assist with vertebral movements v. Variations by Region 1. Discs are thicker in lower spine 2. Relative thickness of disc to vertebral body is greatest in cervical and lumbar   motion allowed Section 1 3  c. Articulations in the Trunk i. Between vertebral bodies = Symphysis Joints ii. Facet Joints (zygophyseal joints) 1. Planar/gliding joints 2. Joint capsules innervated by dorsal rami of that spinal level 3. Thoracic movement is greatly limited due to the bony elements and articular facets. iii. Costovertebral 1. Planar/gliding joints between rib and vertebral bodies 2. Reinforced by the radiate ligaments 3. Each rib typically articulates with its named vertebra and the one superior to it a. With which vertebrae to ribs 1, 10, 11, and 12 articulate? Section 2 4  iv. Costotransverse 1. Planar/gliding joints between tubercle of rib and transverse process of vertebra 2. Reinforced by the costotransverse (superior, medial and lateral) and intra-articular ligaments Section 2 5  v. Sternocostal 1. 1st sternocostal = synchondrosis 2. 2nd-7th sternocostal are synovial joints vi. Costochondral 1. Synchonroses  little or no movement vii. Interchondral 1. At the boarders of the costal cartilages 6-9 2. Synovial planar joints 3. What are floating ribs? viii. Manubrialsternal 1. Symphysis or may be ossified ix. Xiphisternal 1. Synchondrosis or may be ossified Section 2 6  d. Movement and Range of Motion in the Trunk i. Cervical Region 1. Rotation: 90° 2. Sidebending: 40-75° 3. Extension: 90° 4. Flexion: 45-50° 5. Coupled movements: in lower C-spine (C3-C7): sidebending and rotation are coupled in the same direction a. Coupled movements allows greater range than either movement alone ii. Thoracic Region 1. 3-20° flexion/extension 2. 5-10° sidebending 3. 35-50° rotation 4. Coupled movements are highly variable 5. How is thoracic movement affected by the rib cage? iii. Lumbar Region 1. 40° flexion 2. 20° extension 3. 10-20° rotation Section 3 7  e. Movements of the Ribs i. Rotation and elevation/depression occur at costovertebral and costotransverse joints ii. Movements with respiration iii. Upper joints (T1-T6) increase the anterior-posterior diameter = pump handle movement iv. Lower joints (T7-T12) increase the medial-lateral diameter = bucket handle movement Section 3 8 2. Neurovascular Supply to the Spine a. Arterial Supply i. Branches of segmental arteries (arteries coming off the thoracic aorta at each vertebral level) b. Venus Drainage i. Intervertebral veins receive drainage from spinal cord and from vertebral venus plexus Section 4 9  c. Innervation i. Zygophyseal (facet) joints innervated by articular branches off of segmental posterior primary rami (PPRs) ii. Vertebral column innervated by recurrent meningeal branches of segmental spinal nerves (arise immediately after dorsal and ventral roots join to make mixed spinal nerve) 3. Clinical Considerations (see the blue boxes in the text for more detail) a. Osteoporosis b. Laminectomy c. Disc Protrusion d. Spondylolysis (pars interartciularis fracture) e. Spondylolisthesis (anterior slippage of vertebral body) f. Lumbar Puncture Section 4 10