Functional Anatomy of Spine (6).pptx

FUNCTIONAL ANATOMY OF SPINE SBSS 319 BIOKINETICS, EXERCISE & LEISURE UNIVERSITY OF UKZN  (7) Anteriorly convex Anteriorly concave (12 ) Anteriorly convex (5 ) Anteriorly c...

FUNCTIONAL ANATOMY OF SPINE SBSS 319 BIOKINETICS, EXERCISE & LEISURE UNIVERSITY OF UKZN  (7) Anteriorly convex Anteriorly concave (12 ) Anteriorly convex (5 ) Anteriorly concave (5 ) (4 UNIVERSITY OF UKZN 4 UNIVERSITY OF UKZN 5  Principal Variations In Vertebrae of Different Regions Vertebra. Body. Spine. Transverse Process. Cervical (first Short and Small, and with a foramen and second described Oval in shape bifid at the through which the separately) free end vertebral artery runs Long, thin, Heart-shape, and Have small facets for Dorsal with facets for pointing articulation with the heads of ribs downwards tubercle of the rib Point horizontally Short, stout, Lumbar Kidney-shape and outwards, with several horizontal tubercles for attachment of muscles UNIVERSITY OF UKZN The muscles of the back can be divided into three groups – superficial, intermediate and deep: Superficial – associated with movements of the shoulder. Intermediate – associated with movements of the thoracic cage. Deep – associated with movements of the vertebral column. UNIVERSITY OF KWAZULU- 10 NATAL  The superficial back muscles are situated underneath the skin and superficial fascia. They originate from the vertebral column and attach to the bones of the shoulder – the clavicle, scapula and humerus. All these muscles are therefore associated with movements of the upper limb. The muscles in this group are the trapezius, latissimus dorsi, levator scapulae and the rhomboids. The trapezius and the latissimus dorsi lie most superficially, with the trapezius11 UNIVERSITY OF KWAZULU- NATAL TRAPEZIUS The trapezius is a broad, flat and triangular muscle. The muscles on each side form a trapezoid shape. It is the most superficial of all the back muscles. Attachments: Originates from the skull, ligamentum nuchae and the spinous processes of C7-T12. The fibres attach to the clavicle, acromion and the scapula spine. Innervation: Motor innervation is from the accessory nerve. It also receives proprioceptor fibres from C3 and C4 spinal nerves. Actions: The upper fibres of the trapezius elevates the scapula and rotates it during abduction of the arm. The middle fibres retract the scapula and the lower fibres pull the scapula inferiorly. UNIVERSITY OF KWAZULU- 12 NATAL LATISSIMUS DORSI The latissimus dorsi originates from the lower part of the back, where it covers a wide area. Attachments: Has a broad origin – arising from the spinous processes of T6-T12, iliac crest, thoracolumbar fascia and the inferior three ribs. The fibres converge into a tendon that attaches to the intertubercular sulcus of the humerus. Innervation: Thoracodorsal nerve. Actions: Extends, adducts and medially rotates the upper limb UNIVERSITY OF KWAZULU- 13 NATAL LEVATOR SCAPULAE The levator scapulae is a small strap-like muscle. It begins in the neck, and descends to attach to the scapula. Attachments: Originates from the transverse processes of the C1-C4 vertebrae and attaches to the medial border of the scapula. Innervation: Dorsal scapular nerve. Actions: Elevates the scapula. UNIVERSITY OF KWAZULU- 14 NATAL RHOMBOIDS There are two rhomboid muscles – major and minor. The rhomboid minor is situated superiorly to the major. Rhomboid Major Attachments: Originates from the spinous processes of T2-T5 vertebrae. Attaches to the medial border of the scapula, between the scapula spine and inferior angle. Innervation: Dorsal scapular nerve. Actions: Retracts and rotates the scapula. Rhomboid Minor Attachments: Originates from the spinous processes of C7-T1 vertebrae. Attaches to the medial border of the scapula, at the level of the spine of scapula. Innervation: Dorsal scapular nerve. Actions: Retracts and rotates the scapula. 15  The intermediate group contains two muscles – the serratus posterior superior and serratus posterior inferior. These muscles run from the vertebral column to the ribcage, and assist with elevating and depressing the ribs. They also have a slight respiratory function. UNIVERSITY OF KWAZULU- 16 NATAL Serratus Posterior Superior The serratus posterior superior is a thin, rectangular shaped muscle. It lies deep to the rhomboid muscles on the upper back. Attachments: Originates from the lower part of the ligamentum nuchae, and the cervical and thoracic spines (usually C7 – T3). The fibres pass in an inferolateral direction, attaching to ribs 2-5. Innervation: Intercostal nerves. Actions: Elevates ribs 2-5. Serratus Posterior Inferior The serratus posterior inferior is broad and strong. It lies underneath the latissimus dorsi. Attachments: Originates from the thoracic and lumbar spines (usually T11 – L3). The fibres pass in a superolateral direction, attaching to ribs 9-12. Innervation: Intercostal nerves. Actions: Depresses ribs 9-12. 17 18  The deep muscles of the back are well- developed, and collectively extend from the sacrum to the base of the skull. They are associated with the movements of the vertebral column, and the control of posture. The muscles themselves are covered by deep fascia, which plays a key role in their organisation. Anatomically, the deep back muscles can be divided into three layers; superficial, intermediate and deep. UNIVERSITY OF KWAZULU- 19 NATAL SUPERFICIAL The superficial muscles are also known as the spinotransversales. There are two muscles in this group – splenius capitis and splenius cervicis. They are both associated with movements of the head and neck. They are located on the posterolateral aspect of the neck, covering the deeper neck muscles. Splenius Capitis Attachments: Originates from the lower aspect of the ligamentum nuchae, and the spinous processes of C7 – T3/4 vertebrae. The fibres ascend, attaching to the mastoid process and the occipital bone of the skull. Innervation: Posterior rami of spinal nerves C3 and C4. Actions: Rotate head to the same side. Splenius Cervicis Attachments: Originates from the spinous processes of T3-T6 vertebae. The fibres ascend, attaching to the transverse processes of C1-3/4. UNIVERSITY OF KZN 20 UNIVERSITY OF KZN 21 Intermediate There are three intermediate intrinsic back muscles – the iliocostalis, longissimus and spinalis. Together these muscles form a column, known as the erector spinae. The erector spinae is situated posterolaterally to spinal column, between the vertebral spinous processes and the costal angle of the ribs. UNIVERSITY OF KZN 22 Iliocostalis The iliocostalis muscle is located laterally within the erector spinae. It is associated with the ribs, and can be divided into three parts – lumborum, thoracis, and cervicis. Attachments: Arises from the common tendinous origin, and attaches to the costal angle of the ribs and the cervical transverse processes. Innervation: Posterior rami of the spinal nerves. Actions: Acts unilaterally to laterally flex the vertebral column. Acts bilaterally to extend the UNIVERSITY OF KZN 23 vertebral column and head. Longissimus The longissimus muscle is situated between the iliocostalis and spinalis. It is the largest of the three columns. It can be divided into three parts – thoracic, cervicis and capitis. Attachments: Arises from the common tendinous origin, and attaches to the lower ribs, the transverse processes of C2 – T12, and the mastoid process of the skull. Innervation: Posterior rami of the spinal nerves. Actions: Acts unilaterally to laterally flex the vertebral column. Acts bilaterally to extend the vertebral column and head. UNIVERSITY OF KZN 24 Spinalis The spinalis muscle is located medially within the erector spinae. It is the smallest of the three muscle columns. It can be divided into the thoracic, cervicis and capitis. Attachments: Arises from the common tendinous origin, and attaches to the spinous processes of C2, T1-T8 and the occipital bone of the skull. Innervation: Posterior rami of the spinal nerves. Actions: Acts unilaterally to laterally flex the vertebral column. Acts bilaterally to extend the vertebral column and head. UNIVERSITY OF KZN 25 UNIVERSITY OF KZN 26 Deep Intrinsic Muscles The deep intrinsic muscles are located underneath the erector spinae, and are known collectively as the transversospinales. They are a group of short muscles, associated with the transverse and spinous processes of the vertebral column. There are three major muscles in this group – the semispinalis, multifidus and rotatores UNIVERSITY OF KZN 27 Semispinalis The semispinalis is the most superficial of the deep intrinsic muscles. Much like the intermediate muscles, it can be divided by its superior attachments into thoracic, cervicis and capitis. Attachments: Originates from the transverse processes of C4-T10. The fibres ascend 4-6 vertebral segments, attaching to the spinous processes of C2- T4, and to the occipital bone of the skull. Innervation: Posterior rami of the spinal nerves. Actions: Extends and contralaterally rotates the head and vertebral column. UNIVERSITY OF KZN 28 Multifidus The multifidus is located underneath the semispinalis muscle. It is best developed in the lumbar area. Attachments: Has a broad origin – arises from the sacrum, posterior iliac spine, common tendinous origin of the erector spinae, mamillary processes of lumbar vertebrae, transverse processes of T1-T3 and articular processes of C4-C7. The fibres ascend 2-4 vertebral segments, attaching to the spinous processes of the vertebrae. Innervation: Posterior rami of the spinal nerves. Actions: Stabilises the vertebral column. UNIVERSITY OF KZN 29 Rotatores The rotatores are most prominent in the thoracic region. Attachments: Originates from the vertebral transverse processes. The fibres ascend, and attach to the lamina and spinous processes of the immediately superior vertebrae. Innervation: Posterior rami of the spinal nerves. Actions: Stabilizes the vertebral column, and has a proprioceptive function. Minor Deep Intrinsic Muscles: Interspinales: Spans between adjacent spinous processes. Acts to stabilize the vertebral column. Intertranversari – Spans between adjacent transverse processes. Acts to stabilize the vertebral column. Levatores costarum – Originates from the transverse processes of C7- T11, and attaches to the rib immediately below. Acts to elevate the ribs. UNIVERSITY OF KZN 30 UNIVERSITY OF KZN 31  Types of Vertebral General Location Muscles Forward flexors Anterior Lateral flexors Lateral Rotators Lateral Extensors Posterior  LUMBAR FUNCTION NERVE MUSCLES Psoas Major Flexes thigh at hip joint & vertebral L2, L3, sometimes L1 or column L4 Quadratus Lateral flexion of vertebral column T12, L1 Lumborum Interspinales Extends vertebral column Dorsal primary divisions of spinal nerves Extends and laterally bends the Spinal nerves C1-S5 Erector spinae vertebral column, neck and head Multifidus Extends & rotates vertebral column Dorsal primary divisions of spinal nerves Longissimus Extends & rotates vertebral column Dorsal primary divisions Lumborum of spinal nerves Iliocostalis Extension, lateral flexion of vertebral Dorsal primary divisions Lumborum column, rib rotation of spinal nerves  LUMBAR ORIGIN INSERTION MUSCLES Lesser trochanter of femur Psoas Major Bodies and transverse processes of (with iliacus) via iliopsoas lumbar vertebrae tendon Quadratus Apices of transverse processes of L1- Lumborum 4, iliolumbar ligament and posterior Inferior border of 12th rib third of iliac crest lliac crest, sacrum, transverse and Angles of the ribs, spinous processes of vertebrae & transverse and spinous Erector spinae supraspinal ligament processes of vertebrae, posterior aspect of the skull Sacrum, transverse processes of C3- Spinous processes 2-4 Multifidus L5 vertebral levels superior to their origin Longissimus Transverse process at inferior Transverse process at Lumborum vertebral levels superior vertebral levels and mastoid process Iliocostalis Iliac crest and sacrum Angles of the ribs Lumborum UNIVERSITY OF ZULULAND 35