Spine Flashcards
What anatomical qualities enhance the lumbar spine’s ability to bear weight?
• Large vertebral bodies
• Intervertebral discs
• Lordotic curvature
• Many strong ligaments
• Muscular support from segmental and global muscles
• Dense thoracolumbar fascia
How is weight distributed through the lumbar spine?
• 75–80% through vertebral bodies and discs
• 20–25% through facet joints
What is the orientation of lumbar facet joints, and how does it influence movement?
• Oriented in the sagittal plane
• Predominantly allows flexion and extension
• Primarily minimizes rotation
What are the primary ranges of motion (ROM) for the lumbar spine?
• Flexion: 60°
• Extension: 25°
• Lateral flexion: 25°
• Rotation: 12°
What are the key functions of intervertebral discs (IVDs)?
• Absorb and distribute forces
• Maintain proper spacing between vertebral bodies
• Preserve spacing in intervertebral foramina and facet joints
What happens with hypermobility or degeneration of intervertebral discs?
• Approximation of facet joints
• Narrowing of intervertebral foramina
Which part of the intervertebral discs (IVDs) is innervated?
Only the outer 1/3rd of the disc is innervated.
Are intervertebral discs vascularized?
No, IVDs are avascular.
Which ligaments support intervertebral discs anteriorly and posteriorly?
• Anterior Longitudinal Ligament (ALL) supports anteriorly
• Posterior Longitudinal Ligament (PLL) supports posteriorly
What is the annulus fibrosis?
The outer portion of the intervertebral disc, made up of rings of collagen fibers and fibrocartilage.
What is the function of the annulus fibrosis?
Acts as a complex ligament to prevent excessive movement at an individual vertebral segment.
How is the annulus fibrosis attached to surrounding structures?
• Firmly anchored to adjacent vertebrae
• Innermost fibers blend with the nucleus pulposus
• Stabilized by the anterior and posterior longitudinal ligaments
What is the nucleus pulposus?
A gelatinous mass contained within and bound to the innermost fibers of the annulus fibrosis.
What is the water affinity of the nucleus pulposus, and how does it function?
• High affinity for water
• Takes in water during offloading (decreased pressure)
• Squeezes out water during loading (e.g., weight-bearing)
Why are the fluid dynamics of the nucleus pulposus important?
They help transport nutrients and maintain disc tissue health.
How does the nucleus pulposus receive nutrients?
Through diffusion from the marrow of vertebral bodies via cartilaginous endplates.
Where do nerve roots exit the spinal canal?
Through the intervertebral foramina.
What can cause nerve root impingement in the intervertebral foramina?
• Degenerative disc disease
• Degenerative joint disease
• Disc lesions
• Spondylolisthesis
What is stenosis, and how does it affect nerve roots?
Stenosis is the narrowing of the foraminal space or central canal, which can impinge nerve roots.
Which movements can worsen symptoms in cases of stenosis?
• Extension
• Side bending
• Rotation to the affected side
How do movements like extension, side bending, or rotation worsen stenosis symptoms?
They further decrease space in the foraminal area, exacerbating nerve root compression.
What is a Motion Segment?
connection between 2 adjoining vertebras
What are the symptoms of nerve root compression?
• Sensory changes in dermatomal pattern
• Motor weakness in myotomal pattern
• Radicular pain (radiating pain into the lower extremity)
• Low back pain
• Dural tension
• Decreased deep tendon reflexes
• Reproduction of symptoms with increased intraabdominal pressure (e.g., Valsalva, laughing, bowel movements, sneezing)
What sensory pattern is affected in nerve root compression?
Sensory changes occur in a dermatomal pattern.
What motor pattern is affected in nerve root compression?
Motor weakness occurs in a myotomal pattern.
What is radicular pain?
Radiating pain into the lower extremity caused by nerve root compression.
What activities can reproduce symptoms of nerve root compression by increasing intraabdominal pressure?
• Valsalva maneuver
• Laughing
• Bowel movements
• Sneezing
Which reflex is associated with the L4 nerve root?
Patellar reflex.
Which reflex is associated with the S1 nerve root?
Achilles reflex.
What is the myotome for L1-2?
Hip flexion.
What is the myotome for L3?
Knee extension.
What is the myotome for L4?
Ankle dorsiflexion.
What is the myotome for L5?
Big toe extension.
What are the myotomes for S1?
• Ankle eversion
• Plantar flexion
• Hip extension
What is the myotome for S2?
Knee flexion.
What is the purpose of the Valsalva maneuver in nerve root compression testing?
It reproduces symptoms by increasing intraabdominal pressure.
What does the Straight Leg Raise (SLR) test assess?
It assesses dural tension and other factors but is not primarily a test for disc herniation.
What does the Slump test assess?
It assesses dural tension and other factors but is not primarily a test for disc herniation.
What are the three subsystems responsible for spinal stability?
• Passive subsystem: Inert structures, bones, ligaments
• Active subsystem: Muscles
• Neural control
What happens if one of the spinal stability subsystems is ineffective or inefficient?
It affects the stability of the entire spine.
According to Kisner, Colby, & Borstad (2018), what often causes spinal segment instability?
• Tissue damage
• Insufficient muscular strength or endurance
• Poor neuromuscular control
What is the neutral zone in spinal stability?
A midrange/neutral position where the joint capsule and ligaments provide minimal passive resistance and offer minimal stability.
What is the elastic zone in spinal stability?
The zone where inert structures provide passive restraint to stabilize the spinal segment and prevent excessive movement in a given direction.
What happens when a spinal segment moves beyond the elastic zone?
It enters the Plastic zone, where deformation of soft tissues and injury occurs.
Give an example of an inert structure stabilizing the spine.
The Posterior longitudinal ligament limits spinal flexion and stabilizes the spine during flexion.
What role do sensory receptors in inert structures play in spinal stability?
They sense position and changes in position, relaying this information to the central nervous system to contribute to neuromuscular control.
What is the role of the passive subsystem in spinal stability?
Provides structural stability through bones, ligaments, and joint capsules.
How do inert structures stabilize the spine in a specific direction?
By limiting movement in that direction, they provide passive restraint and prevent excessive movement.
What is the role of the active subsystem in spinal stability?
The muscles of the trunk stabilize the spine, act as prime movers, or serve as antagonists to counteract movement caused by gravity during activity.
How do trunk muscles contribute to posture?
The contraction of trunk muscles allows us to maintain upright posture.
What happens when there is weakness in trunk muscles?
• Over-reliance on the passive subsystem
• Increased stress on inert structures
• Impaired sensory feedback to the nervous system
• Disrupted motor input to the muscles
What are global muscles in the active subsystem?
Multisegmental muscles that respond to external loads on the trunk, shifting the center of mass.
Can global muscles stabilize individual spinal segments? Why or why not?
No, they cannot effectively stabilize individual spinal segments because they have little or no direct attachment to the vertebrae.
How do global muscles stabilize the spine indirectly?
Through compressive loading.
What are segmental (core) muscles in the active subsystem?
Deeper muscles with segmental attachments that respond regardless of the direction of motion.
What is the role of segmental (core) muscles?
They support individual spinal segments to maintain stability and prevent stress on inert structures at the limits of motion.
What can happen if an individual spinal segment is unstable?
Compressive loading from global muscles may perpetuate pain by stressing inert tissues at the end range of motion of that segment.
How do segmental muscles differ from global muscles in their function?
• Global muscles: Respond to external loads and shift the center of mass.
• Segmental muscles: Stabilize individual spinal segments regardless of movement direction.
What are the global muscles of the spine?
• Rectus abdominis
• External obliques
• Internal obliques
• Quadratus lumborum (lateral portion)
• Erector spinae
• Iliopsoas
What are the core muscles of the spine?
• Transversus abdominis
• Multifidus
• Quadratus lumborum (deep portion)
• Deep rotators
• Diaphragm
• Pelvic floor
How do the Transversus abdominis (TrA), diaphragm, and pelvic floor work together?
They contract in synchrony to:
• Increase abdominal pressure
• Offload compressive forces from the spine
What is the role of the core muscles during limb movement?
They contract before limb movement to stabilize the spine while the arms and legs are in motion (e.g., during gait).
What are some common tests used to assess core muscle function?
• Diaphragmatic breathing
• Transversus abdominis (TrA), pelvic floor, and multifidus firing
• Dead bug progression
• Bird dog progression
• Side plank
• Front plank
What is one of the major true functions of the core muscles?
To stabilize the spine while the arms and legs are in motion.
What is a disc herniation?
A change in the shape of the annulus fibrosis that causes it to bulge beyond its normal perimeter.
What are the common locations for disc herniation in the lumbar spine?
• Posterolateral
• Lateral
• Central
• Anterior herniation is possible but far less common.
At which spinal levels do 95% of lumbar disc herniations occur?
At L4-L5 or L5-S1, due to greater mechanical stress from supporting weight and acting as a fulcrum during extension and flexion.
What are the symptoms of disc herniation?
• Low back pain
• Radicular pain (radiating to buttock, posterior thigh, leg, and foot)
• Motor weakness
• Dural tension
• Sensory deficits
• Impaired reflexes
How does annulus fibrosis damage typically occur?
• Repeated stress or traumatic rupture
• Overloading the spine in flexion with asymmetrical forward bending and torsional stresses
• Loaded flexion mechanism (e.g., bending over to pick up a pen)
Why do discs take a long time to heal?
• Poor vascularization
• Aneural nature
• Self-healing is possible but results in weak fibrous repair prone to reinjury.
How do symptoms vary with disc herniation?
• Depend on the size and direction of the protrusion
• Depend on the spinal level affected
What symptoms may indicate a large posterior disc protrusion?
• Spinal cord signs
• Loss of bladder control
• Saddle anesthesia
This is a medical emergency!
Do all disc injuries cause symptoms?
No, because the disc is aneural, not all disc injuries are symptomatic. Neurological symptoms only occur if the herniation is severe enough to compress the spinal nerve root.
What are the types of disc herniation?
• Protrusion: Nuclear material is contained by the outer layers of the annulus and supporting ligamentous structures.
• Prolapse: Rupture of nuclear material into the vertebral canal.
What are the subtypes of disc prolapse?
• Extrusion: Nuclear material extends beyond the posterior longitudinal ligament or above and below the disc space, but is still in contact with the disc.
• Sequestration: The extruded nucleus separates from the disc and moves away from the prolapsed area.
What happens when the nucleus pulposus extends into the neural canal?
• Causes an inflammatory reaction
• Irritates the dural sac and its nerve root sleeves
• May irritate the nerve roots themselves
• Often coupled with muscle spasm of lumbar extensors and pelvic muscles
How might a patient present clinically with a disc herniation?
• Antalgic scoliosis (to offload the injured disc)
• Short stride during gait (due to hamstring spasm)
Describe the pain patterns associated with acute phase disc herniation.
• Constant pain (varies in intensity with position or activity)
• Pain is often more severe in the morning because the disc absorbs water overnight in an offloaded position.
How do symptoms change as the disc lesion heals?
• Nuclear matter is resorbed
• Symptoms tend to centralize and move proximally
How do positions and movements affect symptoms in disc herniation?
• Higher disc load positions → Symptoms peripheralize
• Offloaded positions → Symptoms centralize
Centralizing movements and positions help guide treatment and self-care!
What are the key goals and treatments in the acute stage (protection phase) of disc herniation?
• Inflammation management: Ice, NSAIDs, steroid injection
• Pain management: Massage, acupuncture, hydrotherapy, TENS
• Position of ease: Self positional release
• Traction: If relieving
• Tolerable/pain-free movement
• Core activation
• GST, GTO, muscle approximation: To ease spasm in lumbar and pelvic muscles
• Relaxation and breathing exercises
Duration: Generally > 4 weeks
What are the key treatments in the subacute stage (Controlled Motion Phase) and chronic stage (Return to Function Phase)?
• GST/MFR: Address postural dysfunction
• Traction: If relieving
• Centralizing movements: E.g., McKenzie exercises if extension centralizes pain
• Progressing core exercises
• Stretching and mobility: Increase tissue extensibility and address postural imbalances
• Retraining functional movement patterns: Squats, lifts, etc.
• Education: Postural awareness, good ergonomics, reducing prolonged postures
• Relaxation exercises
Subacute Stage Duration: 4-12 weeks
Chronic Stage Duration: 12+ weeks
What are the medical intervention options for disc herniation?
• Surgery: Indicated for patients who have failed conservative treatments (e.g., Physio, Massage, medication, steroid injection)
• Common surgical interventions: Laminectomy and fusion
What are the Red Flags for Cauda Equina Syndrome?
• Loss of bladder or bowel function
• Saddle anaesthesia: Loss of sensation in buttocks and perineum
• Significant lower extremity weakness: May progress to paraplegia
Important:
• Cannot be treated conservatively
• Medical emergency: May result in permanent loss of bladder/bowel function and paralysis if not treated quickly
What are additional Red Flag signs to consider in disc pathology?
• Symptoms cannot be reproduced with testing
• Symptoms don’t improve after a month of treatment
• Unexplained weight loss
What is Degenerative Disc Disease (DDD) and its causes?
• Natural occurrence of aging or secondary to disease, infection, disc herniation, or a bony defect in the spine
• Excessive/accelerated degeneration typically linked to prolonged dysfunctional posture or repetitive loading of the spine
• Degeneration leads to progressive fibrous changes in the nucleus pulposus, disorganization of annular rings, and loss of cartilaginous endplates
What are the effects of degeneration on the intervertebral discs?
• Nucleus pulposus becomes fibrotic and loses the ability to draw in water
• Flatter disc shape leads to segmental instability and abnormal forces on the facets, ligaments, and muscles
• Secondary conditions can include:
-Lumbar sprain/strain
-Facet irritation
-Stenosis (narrowing of central or foraminal space)
Why is disc herniation rare in elderly individuals?
Due to degenerative disc disease, the disc flattens, reducing its ability to bulge, and increasing the risk of other issues such as lumbar sprains or facet irritation.
What are the symptoms of mild degeneration in Degenerative Disc Disease?
• Stiffness
• Increased muscle tension
• Relatively asymptomatic
What are the symptoms of moderate/severe degeneration in Degenerative Disc Disease?
• Increased muscle resting tension and spasm
• Restricted ROM
• Weakness
• Bony changes to stabilize the segment
• Neurological symptoms due to stenosis and spinal nerve compression
What is the treatment for Degenerative Disc Disease?
• Reduce muscle resting tension and spasm
• Mobilize restricted segments
• Traction: To increase joint and foraminal space
• Normalize lumbar and pelvic posture
• Increase or maintain ROM
• Strengthen core and pelvic muscles
• Encourage movement
• Relaxation exercises
What is the cause and treatment for Lumbar Sprain/Strain?
• Cause: Often related to prolonged dysfunctional posture and disruption of the 3 subsystems of spinal stability.
• Can be traumatic or insidious onset
• For insidious low back pain, do not assume it’s muscular. Perform postural assessment, functional testing, and lumbar instability tests!
What is the treatment approach for acute lumbar sprain/strain?
• Gentle MFR and GST to reduce tissue impairments (spasm, MFR, TRPS)
• Positional release, GTO, muscle approximation
• Pain-free movement
• Muscle setting
• Relaxation exercises
What is the treatment approach for subacute to chronic lumbar sprain/strain?
• Dynamic techniques
• MFR and GST to reduce tissue impairments
• Stretching and strengthening to improve posture and movement
• Relaxation exercises
What are facet joints and how are they supported?
• Facet joints are synovial joints
• They are enclosed in a joint capsule and supported by ligaments
What movements aggravate facet joints?
• Extension approximates facet joints
• Ipsilateral rotation and lateral flexion also aggravate facet joints
How is facet pain typically described?
• Point-specific pain (especially during provocative movements)
• Deep, achey, and diffuse pain (if referring pain)
What is Kemp’s test used for?
Kemp’s test is used to provoke facet joint pain
How are the disc and facet joints related biomechanically?
• The disc and facets make up a three-joint complex (vertebrae, intervertebral disc (IVD), and facet joints)
• They are biomechanically interrelated, with proper disc integrity and size essential for maintaining proper alignment of the facets and preventing asymmetrical movements and abnormal stress
What are the causes of facet joint irritation or pathology?
• Prolonged dysfunctional posture
• Repetitive trauma
• Acute trauma
• Disc injury
What is the difference between acute and chronic facet pathology?
• Acute pathology results from short-term irritation/inflammation
• Chronic pathology results from prolonged loading, leading to degeneration and osteoarthritis
What is Osteoarthritis also known as?
Also referred to as degenerative disc disease (DDD) or spondylosis
What are the common causes of Osteoarthritis?
• Dysfunctional posture
• Severe trauma
• Prolonged immobilization
• Repetitive trauma
• Degenerative changes in the disc
What happens in the early stage of Osteoarthritis?
Hypermobility and instability are present, affecting the entire three-joint complex
What is the progression of Osteoarthritis over time?
• Stress from altered joint mechanics leads to osteophyte formation with spurring and lipping along the joint margins and vertebral bodies
• This causes progressive loss of ROM and bony stenosis
How does degeneration at one joint segment in Osteoarthritis affect the spine?
Degeneration at one segment will affect neighboring spinal segments
What are the symptoms of Osteoarthritis?
• Decreased ROM
• Weakness
• Sensory deficits
• Decreased reflexes
What are the common conditions associated with Osteoarthritis?
• Lumbar sprain/strain
• Nerve impingement
What movements increase pain and neurological symptoms in Osteoarthritis?
Lumbar extension and ipsilateral side bending
What is the treatment for facet irritation and Osteoarthritis?
• Cold hydrotherapy if spasm and inflammation are present
• GST, GTO, and muscle approximation to treat muscle resting tension and spasm
• Normalize lumbar and pelvic posture
• Strengthen core and pelvic musculature
• Encourage movement (walking, swimming, resistance training)
• Mobilize affected segments into flexion and contralateral rotation/side bending
• Minimize provocative postures while acute
• Optimize ergonomics and avoid repetitive loading and prolonged postures
What is Spondylolysis?
A defect or fracture of the pars interarticularis, most commonly at L5
What are the types of Spondylolysis?
• Dysplastic (congenital)
• Isthmic (sports injury)
• Degenerative
• Traumatic
What is the most common type of Spondylolysis?
The most common type is isthmic spondylolysis, which occurs in active children and adolescents
What happens if a Spondylolysis fracture persists?
The superior vertebra may slip anteriorly, which is called spondylolisthesis
What are the symptoms of Spondylolysis?
• “Beltline” pain across the low back
• Hyperlordotic posture, often coupled with hamstring restriction or spasm
• Initially sharp pain, becoming achey over time
• May radiate into gluteals
• Rest alleviates pain
• Extension and rotation aggravate pain
What are some tests for Spondylolysis?
• AROM extension will aggravate pain
• Positive lumbar instability test
• ‘Step deformity’ in the lumbar spine
• Prone bilateral hyperextension test
• X-ray or MRI
What is a Compression fracture?
• Most common at the L1 segment (also lower T spine)
• Caused by osteoporosis or trauma (acute or repetitive)
• Often presents insidiously
What are the symptoms of a Compression fracture?
• Sharp, focal pain in the spine
• Pain may radiate anteriorly, mimicking heart and lung pathology
• Typically no spinal nerve involvement
• Often causes significant compensatory thoracic hyperkyphosis
What are the assessment tests for a Compression fracture?
• Heel drop test
• Compression (aggravates pain)
• Traction (alleviates pain)
• X-ray or MRI
What is the treatment for Spondylolysis and Compression fractures?
• Pain and inflammation management in the acute stage
• Decrease, but do not eliminate muscle spasm in lumbar muscles or glutes/hamstrings
• Normalize posture
• Strengthen core and posterior chain
• Regain length and muscle extensibility in posterior chain and lumbar muscles
• Graded return to function and sport
What are other conditions related to spine pathologies?
• Ankylosing spondylitis
• Rheumatoid arthritis (review inflammatory arthritides)
