Anatomy and specie tests of spine, pelvis, and temporomandibular joint

Spine and pelvis region

Components of spine (vertebral column)

• 24 moveable bones
• 9 fused bones
  • Divided into 5 areas- cervical, thoracic, lumbar, sacral, and coccygeal

Function of spine

• Provides a strong and flexible framework that supports the body’s weight, allowing for standing, walking, and moving freely.
• Encases and protects the spinal cord
• Connecting discs allow for a wide range of motion, including flexion, extension, rotation, and lateral flexion.
• Thoracic spine protects vital internal organs such as the heart and lungs.
• Carries nerve signals between the brain and the body, enabling us to feel, move, and control bodily functions.
• Maintain proper balance and posture by distributing the body’s weight evenly.
• Plays a role in breathing, digestion, and other involuntary movements.

Bony structures

• Typical components in definitions below

Special bony components of each segment

• Cervical
  • C1 and C2 allow for rotation without compression of spinal cord
• Costotransverse and costovertebral
  • Articulation between ribs and transverse processes of spine
• Thoracic
  • Prominent (easily palpable) spinous process
• Lumbar
  • Largest and most prominent (easily palpable) spinous process
• Sacrum
  • Composed of 5 fused bones
• Ilium
  • Made of 3 fused bones- ischium, ilium, and pubis

Special joints of spine

• Atlanto-occipital joint- articulation between occipital bone and C1 which allows head nodding to occur
  • Atlanto-axial joint- articulation between C1 and C1 which allows for head rotation
• Facet joints
  • Aid in movement of spine as a whole
• Intervertebral joints
  • Allow for movement at single vertebral body and assist with transferring load from one vertebral body to another
• Sacroiliac joints
  • Aid in movements of lower axial skeleton and lower extremities

Other important features of spine

• Intervertebral discs
  • Annulus fibrosis
    • Composed of collagen fibers, fibrocartilage, and water
    • Vascularized and neural connections
    • Functions to maintain integrity of vertebral column during compression, torsion, shearing, and distracting forces
  • Nucleus pulposus
    • Composed of proteoglycans and water with minimal collagen
    • Avascular and no neural connections
    • Functions to maintain integrity of vertebral column during compression, torsion, shearing, and distracting forces
  • Vertebral endplate
    • Composed of proteoglycans, collagen, fibrocartilage, and water
    • Functions to diffuse nutrients to annulus fibrosis and nucleus pulposus

Ligaments

• Alar
  • Connects dens to occipital condyle
  • Functions to limit flexion, contralateral lateral flexion, and contralateral rotation
• Anterior longitudinal ligament
  • Connects anterior and lateral surfaces of vertebral bodies from C2- sacrum
  • Function to reinforce the anterolateral portion of the intervertebral discs
• Posterior longitudinal ligament
  • Located on the posterior surface of vertebral bodies from C2- sacrum
  • Function to prevent hyperflexion of the vertebral column and to protect the spinal cord from foreign objects and displaced disc material.
• Ligamentum flavum
  • Connects vertebra to the lamina above it; runs from C2-sacrim
  • Function to limit flexion (greatest in lumbar spine)
• Interspinous ligament
  • Runs between spinous processes
  • Function to limit flexion
• Iliolumbar ligament
  • Connects L5 vertebrae to ilium
  • Functions to limit motion between L5 and S1

Capsule

• Facet joints
  • Role is to provide reinforcement to ligaments by limiting motion and stabilizing spine
• Sacroiliac joints
  • Role is stabilizing the sacroiliac joint, limiting its movement, and protecting the joint by distributing biomechanical loads.

Nerves

• Spinal nerves are mixed nerves that connect the spinal cord to the rest of the body. They carry both sensory (dorsal rami) and motor (ventral rami) information between the central nervous system (brain and spinal cord) and the peripheral nervous system (body and muscles).
• Location of spinal nerves
  • Cervical: exit at the level above the associated vertebrae
  • Thoracic/lumbar: exit below the level of associated vertebrae

Spinal and pelvis movements

General rules regarding facet joint opening and closing

• Flexion (bending forward):
  • When you bend forward, the facet joints on the back of the spine open up, allowing for more space between the vertebrae.
• Extension (bending backward):
  • Conversely, when you bend backward, the facet joints close together, creating a more stable and compressed position.
• Sidebending:
  • During sidebending, the facet joints on the side you are bending towards close, while the facet joints on the opposite side open.
• Rotation:
  • During rotation, the facet joints on the ipsilateral side compress together, while the facet joints on the opposite side tend to open.

Joint movements (arthrokinematics)

• Flexion
  • Upper facets move anterior and proximally while tilted anteriorly
• Extension * Upper facets move down and posterior while tilted posteriorly
• Lateral bending
  • Right lateral bending
    • Upper facet moves down and anterior
      • Causing facet closure on right side and opening on left side
  • Left lateral bending
    • Upper facets moves upward and posterior
      • Causing facet closure on left side and opening on right side
• Cervical rotation
  • Right rotation
    • Facets glide down and posteriorly- causing facet joint closure
      • This would be how therapist would close facet
  • Left rotation
    • Facets glide anteriorly- causing facet opening
      • This would be how therapist opens facet

Coupled movements

• Cervical spine
  • C1: lateral bending and rotation occur in different directions (occurs if spine in neutral, flexion, and extension)
  • C2-C7: lateral bending and rotation occurring in the same direction (occurs if spine in neutral, flexion, and extension)
• Lumbar/thoracic spine
  • If spine in flexion: side bending and rotation will occurring in same direction
  • If spine in extension/neutral: side bending and rotation will occur in opposite directions
• Lumbopelvic joint
  • When in flexion: lumbar spine flexes followed by pelvis rotation anteriorly, ending with hip flexion
  • When in extension (when coming from flexed position): hips extend followed by pelvis rotating posteriorly, and spine extending
• Sacroiliac joint
  • Nutation: flexion of sacrum causes posterior tilt of ilium (in frontal plane)
  • Counternutation: extension of sacrum causes anterior tilt of ilium (in frontal plane)
  • Anterior innominate: anterior superior iliac spine (ASIS) moves downward (in sagittal plane)
  • Posterior innominate: anterior superior iliac spine (ASIS) moves upward (in sagittal plane)

Special tests spine and pelvis

Cervical spine

• Vertebral artery test
  • Patient supine with head supported and over edge of mat; therapist passively extends head/neck and hold for 30 seconds, progress to passively rotate and side-bending with extension-holding each position for 30 seconds
    • Tests the integrity of vertebrobasilar vascular system
  • Positive: symptoms of dizziness, dysphagia diplopia, ataxic gait, nystagmus- red flag and therapist does not progress with any movements of cervical spine
    • Vertebral artery test should always be performed prior to cervical spine mobilization- if not performed, this is considered sub-standard care and can be life-threatening
• Flexion rotation test
  • Patient in supine with maximal flexion of neck performed with rotation to let and right
    • Provocative test for atlantoaxial dysfunction or cervicogenic headache
    • Positive: reproduction of headache symptoms or loss of 10 degrees of mobility when comparing left and right rotation (when compared to each side)
• Spurling’s test (foraminal compression)
  • Patient sitting with head laterally bending towards involved side while therapist applies pressure straight down
    • Confirms cervical root dysfunction
  • Positive: pain and paresthesia in dermatomal pattern of cervical root
• Cervical compression test
  • Patient sitting and neck passively moved into lateral flexion and rotation to the non-painful side, followed by extension. Repeat the painful side.
    • Identifies intervertebral foramen and/or facet dysfunction
  • Positive: pain and paresthesia in dermatomal pattern of cervical root or localized pain in neck if facet dysfunction
• Distraction test
  • Patient sitting with head passively distracted
    • Identifies intervertebral foramen and/or facet dysfunction
  • Positive: decrease in symptoms or decrease in upper limb pain
• Lhermitte’s sign
  • Patient long sitting on mat; therapists passively flex patient’s head and hip while keeping knee in extension. Repeat with the other hip.
    • Identifies upper neuron lesions
  • Positive: electrical pain down spine and into upper or lower limbs
• Alar ligament test
  • Patient seated and therapist palpates C2 spinous process; the therapist passively flexes the upper cervical spine with lateral flexion and rotation
    • Tests integrity of alar ligament
  • Positive: Inability to palpate C2 and/or inability to feel movement at C2

Thoracic spine

• Rib sparing
  • Patient prone; beginning at upper ribs apply posterior/anterior force to rib moving through the entire rib cage. Also perform in a side-lying position.
    • Tests rib mobility
  • Positive: pain, excessive motion of rib, or restriction of rib

Lumbar spine

• Slump test
  • Patient sits with knees flexed and neutral neck and head; progress through the following steps- passively flex head and neck, passively extend knee, passively dorsiflex ankle of limb- repeat with opposite leg
    • Therapist will stop at a step if reproduction of symptoms occurs
      • Tests for neurological dysfunction of lower extremity
    • Positive: pain, paresthesias, numbness/tingling, and other neurological symptoms
• Prone instability test
  • Patient prone with torso supported on mate, legs off the edge with both feed supported on the ground. Therapist applies posterior/anterior springing throughout the lumbar spine to identify painful segments. Therapist then instructs patient to lift legs off floor and performs same posterior/anterior springing
    • Tests instability of lumbar spine
    • Positive: decreased pain during posterior/anterior springing with the legs raised compared to when the feet are supported on the ground
• Quadrant test
  • Patient standing
    • Facet dysfunction: instruct patient to lateral bend to left, rotate to right, and maximally extend to compress facet joint on left. Repeat on the opposite side.
    • Intervertebral foramen: instruct patient to lateral bend left, rotate left, and maximally extend to close intervertebral foramen on left. Repeat on the opposite side.
      • Tests compression of neural structures at facet and intervertebral foramen
    • Positive: pain or paresthesias in dermatomal pattern or localized pain if facet dysfunction
• Bicycle test
  • Patient positioned on stationary bike. In erect posture, patient rides bike at set pace/speed with time observed; patient then rides bike at set pace/speed in slumped position with time observed
    • Differentiates between intermittent claudication and spinal stenosis due to position
  • Positive: Individuals with spinal stenosis will tolerate riding bike with slumped posture longer than when in erect posture

Neurological dysfunction

• Lower limb tension tests- assists with identifying peripheral nerve injury by placing the lower limb in positions of that will stress nerve

Sacroiliac

• Gillet’s test
  • Patient standing; therapist places one thumbs under posterior iliac spine (PSIS) of unilateral extremity and other thumb in center of sacrum. The patient then flexes knee and hip while the therapist palpates PSIS and observes for movement.
    • Assess posterior movement of ilium
  • Positive: no movement of ilium or sacrum (ilium has lost mobility)
• Gaenslens’s test
  • Patient side-lying at edge of mat with bottom leg maximally flexed at hip and knee. Therapist passively extends uppermost limb
    • Tests for sacroiliac dysfunction
  • Positive: pain in sacroiliac joint
• Long sitting
  • Patient supine with therapist palpating medial mallelous- therapist observes alignment. The therapist then asks the patient to come to a long sitting position to observe if alignment at medial mallelous is still present.
    • Tests for leg length discrepancy due to sacroiliac joint
  • Positive: one leg observed longer when coming in long sitting position compared to supine position
• Sidelying compression test
  • Patient side-lying with side of dysfunction facing upward toward therapist. Therapist palpates iliac crest and then applies force down through ilium for up to 30 seconds
    • Identifies sacroiliac dysfunction
  • Positive: reproduction of pain
• Supine iliac gapping
  • Patient supine with therapist crossing their arms and placing their hands on patient’s anterior superior iliac spine (ASIS)- each hand on the medial aspect of the ASIS and pushing out laterally
    • Identifies sacroiliac dysfunction
  • Positive: sacral symptoms relieved

Temporomandibular joint (TMJ)

• Elevation (Closing):
  • Contraction of the masseter, temporalis, and medial pterygoid muscles raises the mandible.
• Depression (Opening):
  • Relaxation of the elevator muscles and contraction of the digastric, geniohyoid, and mylohyoid muscles lowers the mandible.
• Protrusion (Forward Movement):
  • Contraction of the lateral pterygoid muscles moves the mandible forward.
• Retrusion (Backward Movement):
  • Contraction of the posterior fibers of the temporalis muscles moves the mandible backward.
• Lateral Deviation (Side-to-Side Movement):
  • Contraction of the lateral pterygoid muscle on one side moves the mandible toward that side.

Special tests of TMJ

• TMJ compression
  • Patient sitting or supine; therapist stabilized patient’s head with one hand while the other hand pushes mandible superiorly causing a compressive load to the TMJ
    • Assess pain of the retrodiscal tissues
  • Positive: pain in the TMJ