The Spinal Column and Thorax

ESAT 3600Fundamentals of Athletic

Training

Main Functions

Skull Protect brain

Thorax Absorb forces of impact Muscle attachment

Vertebral column Provides framework and foundation for most movements of body and extremities

Muscle attachment Protects spinal cord

Vertebral Column

7 cervical 12 thoracic 5 lumbar 5 sacral 4-5 coccygeal Sacral and coccygeal are fused

Shapes of Normal Spine Cervical lordosis

Contributes to mobility of head Thoracic kyphosis Lumbar lordosis

Contributes to “springiness” of spine

Sacral kyphosis Helps to transmit forces of body weight through trunk

Bony Anatomy Review Vertebral body Vertebral arch Transverse processes

Spinous process Articulating surfaces facets

Vertebral Column Structure All vertebrae are similar in general structure

2 factors change when view from cervical to lumbar Structures become progressively larger

Direction of articulating surfaces change

Facets Different orientations allow for: varied degrees of movement between 2 adjacent vertebrae

Change amounts of tension, compression, and shear forces

Vertebral Column Structure Body of vertebra are load bearing portion of vertebra

Lumbar region bears more load than cervical region Lumbar region has larger vertebrae

Cervical Vertebrae Body is more rectangular shaped

Facets are flat and tilted anteriorly

Axis and atlas do not follow basic rules

Thoracic Vertebrae Body has triangular shape

Facets are set oblique, and angle toward each other slightly

Lumbar Vertebrae Body is rounder

Bean shaped Facets are almost vertical and face each other

Intervertebral Disks

Consists of annulus fibrosis and nucleus pulposus

Annulus fibrosis

Outermost layer is regular fibrous tissue

Inner portion is fibrocartilage Concentric layers

Nucleus Pulposus Distributes stresses between vertebrae during flexion and extension Lateral movements also

Forward bending = backward movement

Backward bending = forward movement

Disk Damage Compression and shear of vertebral discs is associated with LBP

3 factors that increase shear and compression Amount of weight lifted Distance held from the vertebral column

Amount of trunk flexion used when lifting

Ligaments of Vertebral Column Anterior longitudinal ligament

Posterior longitudinal ligament

Ligaments of Vertebral Column Supraspinous ligament

Interspinous ligament

Ligaments of Vertebral Column Ligamentum flavum

Intertransverse ligament

Ligaments of Vertebral Column Ligamentum nuchae Atlantoaxial ligament Transverse ligament

Hangman’s ligament Transverse process to transverse process of atlas

Movement in the Spine Movement between individual vertebrae

Movement of entire region Movement of entire spine

Movements of the Spine

Vertebral Column Stability Weak bony stability Most stability from ligaments and muscles

Muscle stabilizers Abdominals

Prevent hyperextension Erector spinae

Compresses column

Thorax 12 Thoracic vertebrae 12 pairs of ribs 1st 7 have direct cartilaginous connection to sternum

Lower 5 connected to sternum by cartilaginous connection to the 7th costal cartilage or not at all

Trunk and Movement Trunk helps to contribute force to movement

Movement of intervertebral joints position trunk so that the upper extremity is in optimal position Throwing tasks

Spinal Muscles Spinal muscle group

O & I on spinous process Transversospinal muscle group

O on transverse process; I on spinous process

Spinotransversal muscle group O on spinous process; I on transverse process

Role of Muscles in Trunk Alignment Rectus abdominis

Prevents lumbar hyperextension & anterior pelvic tilt

Erector spinae group Prevent lumbar flexion

Iliopsoas and rectus femoris Prevent hip extension

Hamstrings and gluteals Prevent hip flexion

Splenius capitis O: spinous processes of C7-T3, inferior half of ligamentum nuchae

I: mastoid process and lateral 1/3 of superior nuchal line

A: bilaterally extends head and neck; unilaterally flexes and rotates head and neck to same side

Splenius cervicis O: spinous process of 3rd-6th thoracic vertebrae

I: posterior transverse processes of the 1st, 2nd, 3rd cervical vertebrae, sometimes 4th cervical vertebrae

A: bilaterally extends head and neck; unilaterally laterally flexes and rotates neck to same side

Erector Spinae - Iliocostal Branch (Iliocostalis lumborum) O: anterior surface of tendon arising from sacrum, spinous processes of lumbar and 11th & 12th thoracic vertebrae, medial lip of the iliac crest

I: inferior borders of angles of the lower 6 or 7 ribs

A: bilaterally extends spine; unilaterally lateral flexion of spine

Erector Spinae - Iliocostal Branch (Iliocostalis thoracis) O: superior borders of the angles of the lower 6 ribs

I: into the angles of the upper 6 or 7 ribs and into the transverse process of the C7

A: bilaterally extends spine; unilaterally lateral flexion of spine

Erector Spinae - Iliocostal Branch (Iliocostalis cervicis) O: superior borders of the angles of the 3rd-6th ribs

I: posterior tubercles of transverse processes of the 4th, 5th, & 6th cervical vertebrae

A: bilaterally extends spine; unilaterally lateral flexion of spine

Erector spinae - Longissimus Branch (Longissimus thoracis)

O: common tendon w/ iliocostalis lumborum, fibers from transverse and accessory processes of lumbar vertebrae and thoracolumbar fascia

I: tips of transverse process of all thoracic vertebrae and the lower 9 or 10 ribs between the tubercles and angles

A: bilaterally extends vertebral column; draws ribs down; unilaterally laterally flexes vertebral column

Erector spinae - Longissimus Branch (Longissimus cervicis)

O: transverse processes of T 1-5

I: transverse processes of C 2-6, sometimes transverse process of atlas

A: bilaterally extends neck; unilaterally laterally flexes neck

Erector spinae - Longissimus Branch (Longissimus capitis)

O: transverse processes of T 1-5, articular processes of C 4-7

I: posterior margin of mastoid process

A: bilaterally extends head; unilaterally laterally flexes and rotates head to same side

Erector spinae - Spinalis Branch (Spinalis thoracis)

O: spinous processes of L 1-2, T11-12

I: spinous processes of upper thoracic vertebrae

A: bilaterally extends spine; unilaterally laterally flexes spine

Erector spinae - Spinalis Branch (Spinalis cervicis)

O: lower portion of ligamentum nuchae, spinous processes of C7 and sometimes T1-2

I: spinous processes of axis and sometimes spinous processes of C3-4

A: bilaterally extends spine; unilaterally laterally flexes spine

Quadratus lumborum

O: iliolumbar ligament, posterior part of iliac crest

I: inferior border of 12th rib and transverse processes of upper 4 lumbar vertebrae

A: lateral flexion of lumbar spine, assist with inspiration

Multifidus A series of pairs of small muscles

extending the full length of the spine just superficial to the rotatores and each spanning 2 or 3 intervertebral spaces

O: posterior surface of sacrum, dorsal end of iliac crest, mamillary and transverse processes of L & T vertebrae, articular processes of C4-7

I: spinous processes of all vertebrae except atlas

A: unilaterally laterally flexes and rotates spine to opposite side; bilaterally extends spine

Rotator brevis Series of pairs of small

muscles extending from sacrum to axis

O: transverse processes of vertebrae

I: bases of spinous processes of 1st vertebrae above

A: unilaterally rotation of spine to opposite side; bilaterally extends spine

Rotator longus Series of pairs of small

muscles extending from sacrum to axis

O: transverse processes of vertebrae

I: bases of the spinous processes of 2nd vertebrae above

A: unilaterally rotation of spine to opposite side; bilaterally extends spine

Scalenus anterior

O: scalene tubercle and ridge on superior surface of 1st rib

I: anterior tubercles of transverse of C3-6

A: bilaterally flexes neck and raises 1st rib; unilaterally laterally flexes and rotates C spine to opposite side

Scalenus medius

O: superior surface of 1st rib behind subclavial groove

I: posterior tubercles of transverse processes of C2-7

A: bilaterally flexes neck and raises 1st rib; unilaterally laterally flexes and rotates C spine to opposite side

Scalenus posterior

O: outer surface of 2nd rib behind attachment of serratus anterior

I: posterior tubercles of transverse processes of C4-6

A: bilaterally flexes neck and raises 2nd rib; unilaterally laterally flexes and rotates C spine to opposite side

Sternocleidomastoid O:Sternal head – anterior

surface of manubrium; Clavicular head – superior surface of medial 1/3 of clavicle

I: lateral surface of mastoid process, lateral ½ of the superior nuchal line

A: bilaterally flexes head; unilaterally draws head to ipsilateral shoulder, rotates head to opposite side

External Oblique

O: external surfaces and inferior borders of ribs 5-12

I: linea alba, inquinal ligament and anterior half of iliac crest along outer lip

A: unilaterally rotates trunk to opposite side, laterally flexes to same side; bilaterally flexes trunk anteriorly, anterior support to organs and lumbar spine, prevents anterior tilt of pelvis

Internal Oblique O: lateral 2/3 of inquinal ligament and anterior 1/3 of middle line of iliac crest; middle 1/3 of iliac crest and thoraco lumbar fascia

I:crest of pubis and linea alba; inferior border of ribs 10-12

A: unilaterally rotates and laterally flexes trunk to same side; bilaterally flexes spine

Rectus Abdominis O: pubic crest and symphysis pubis

I: costal cartilage of ribs 5-7 and side of xiphoid process

A: flexion and lateral flexion of trunk, anterior support to organs and lumbar spine, prevents anterior tilt of pelvis

Transverse abdominis O: lateral 1/3 of the inquinal ligament, anterior 2/3 of inner lip of iliac crest, thoracolumbar fascia, inner edges of lower 6 costal cartilages

I: linea alba A: constricts abdominal contents, assists in forced expiration