CHAPTER 9: THE SPINAL COLUMN AND THORAX KINESIOLOGY Scientific Basis of Human Motion, 12 th edition Hamilton, Weimar & Luttgens Presentation Created by TK Koesterer, Ph.D., ATC Humboldt State University Revised by Hamilton & Weimar McGraw-Hill/Irwin Copyright 2012 by The McGraw-Hill Companies, Inc. All rights reserved.
SPINAL COLUMN: STRUCTURE 7 Cervical Vertebrae 12 Thoracic Vertebrae 5 Lumbar Vertebrae Sarcrum Coccyx (7 ) (12 ) (5 ) Fig 9.1 (5 ) 9A-2
ARTICULATION OF VERTEBRAL BODIES Cartilaginous joint. Intervertebral discs of fibrocartilage. Outer fibrous rim (annulus fibrosus). Nucleus pulposus Permits compression in any direction & some torsion. Shock absorbers. Fig 9.2 9A-3
LIGAMENTOUS REINFORCEMENT Anterior longitudinal ligaments. Posterior longitudinal ligament. Fig 9.3a & 9.4a 9A-4
MOVEMENTS OF THE SPINE AS A WHOLE Flexion Fig 9.11a & b Hyperextension 9A-5
MOVEMENTS OF THE SPINE AS A WHOLE Lateral flexion Fig 9.11c & d Rotation 9A-6
REGIONAL CLASSIFICATION OF SPINAL MOVEMENTS Atlanto-occipital joint Flexion & extension, hyperextension. Slight lateral flexion. Atlantoaxial joint Rotation Remaining cervical joints Flexion & extension, hyperextension. Lateral flexion. Rotation 9A-7
REGIONAL CLASSIFICATION OF SPINAL MOVEMENTS Thoracic region Moderate flexion Slight hyperextension Moderate lateral flexion Rotation Lumbar Flexion & extension, hyperextension Lateral flexion Slight rotation 9A-8
FACTORS INFLUENCING STABILITY & MOBILITY OF THE SPINE Pressure & Tension Stresses: Discs push vertebrae apart & ligaments pull them together. Anteroposterior Curves: Influence the nature & degrees of motion in different regions. Relative Thickness & Shape of Discs: Greater freedom of motion where discs are thick. Thickness & Strength of Ligaments: Regional differences influence motions permitted. 9A-9
MUSCLES OPERATING SPINAL COLUMN Obliquus Externus Abdominis Function: Singly: laterally flex & rotate spine to opposite side. Together: flex thoracic & lumbar spine. Fig 9.15 9A-10
MUSCLES OPERATING SPINAL COLUMN Obliquus Internus Abdominis Function: Singly: laterally flex & rotate spine to the same side. Together: flex thoracic & lumbar spine. Thoracolumbar fascia Obliquus Internus abdominis Rectus sheath (anterior leaf) Inguinal ligament Fig 9.16 9A-11
MUSCLES OPERATING SPINAL COLUMN Rectus Abdominis Function: Singly: laterally flex spine. Together: flex thoracic & lumbar spine. Fig 9.17 9A-12
MUSCLES OPERATING SPINAL COLUMN Transversus Abdominis Function: Stabilize trunk. Fig 9.18 9A-13
MUSCLES OPERATING SPINAL COLUMN Erector Spinae Function: Bilateral: extends head & spine. Unilateral: rotates spine to same side. Fig 9.21 9A-14
MUSCLES OPERATING SPINAL COLUMN Deep Posterior Spinal Muscles Function: Symmetrical: extends & hyperextends spine. Asymmetrical: rotates spine to opposite side and assists in lateral flexion. Fig 9.22 9A-15
MUSCLES OPERATING SPINAL COLUMN Sternocleidomastoid Function: Together: flex neck & head. Singly: laterally flex head & neck, and rotate to opposite side. Fig 9.25 9A-16
MUSCLES OPERATING SPINAL COLUMN Psoas Function: Singly: laterally flex lumbar spine. Together: stabilize spine. Fig 7.14 9A-17
THE THORAX: STRUCTURE Bony-cartilaginous cage Formed by ribs & cartilages Sternum Thoracic vertebrae 7 true ribs 5 false ribs 2 floating ribs Fig 9.30 9B-18
STRUCTURE Ribs Articular surface Tubercle Shape All but the lowest two articulate with the sternum. 9B-19
STRUCTURE 1 st, 10-12 th ribs each articulate with one vertebrae. All others articulate with two adjacent vertebrae. Nonaxial: permits slight gliding. Fig 9.31 9B-20
STRUCTURE Except ribs 11 & 12, Each also has an articulation between: Tubercle of rib. Transverse process of vertebrae. Fig 9.32 9B-21
STRUCTURE Sternocostal joints Sternocostal Costochondral Interchondral Intersternal Fig 9.33 9B-22
MOVEMENTS OF THORAX Increase in Transverse diameter Increase in Anteroposterior diameter Increase in Vertical Diameter Fig 9.34 9B-23
PHASES OF RESPIRATION Pre-inspiration: brief static phase that precedes the intake of air. Inspiration: expansion of thorax & taking in of air. Pre-expiration: brief static phase following inspiration. Expiration: outflow of air & decrease in thoracic volume. 9B-24
MUSCLES WITH PRIMARY FUNCTION IN RESPIRATION Diaphragm Dome-shaped sheet between thoracic & abdominal cavities. Function: Inspiration Fig 9.35 9B-25
MUSCULAR ANALYSIS OF RESPIRATION Inspiration: Diaphragm, scalenes, intercostals. Sternocleidomastoid, serratus posterior superior, levatores costarum, quadratus lumborum, erector spinae, pectoralis major & minor. Expiration: Quiet is passive. Abdominals, erectors spinae, transverse thoracic, intercostals. 9B-26