Lumbar Spine Anatomy and Motion Quiz

Lumbar Spine Problems

• The lumbar spine comprises five vertebrae (L1-L5), facet joints, and the sacrum.
• The vertebrae and intervertebral discs transmit weight, help with posture and movement.
• Objectives for the lecture include memorizing clinical anatomy and biomechanics, defining low back pain syndrome, describing pathological classifications of LBP and common conditions, and identifying red flags.

Objectives

• Learn the clinical anatomy and biomechanics related to the lumbar spine.
• Understand the characteristics of low back pain syndrome.
• Learn different classifications of low back pain and associated conditions.
• Identify red flags of possible serious underlying conditions.

Facet Joints and Lumbar Spine Motions

• Facet joint orientation influences lumbar spine movements.
• Questions to consider: How do facet joints direct lumbar spine motions? What are common pain types? What are common lumbar pathological conditions?

Vertebral Column Function

• The vertebral column transmits the upper body's weight to the lower limbs.
• It protects the spinal cord and supports trunk movement.
• It provides stability, flexibility, and protection.
• The vertebral column consists of 33 vertebrae and 23 intervertebral discs.
• The 33 bones are categorized into cervical, thoracic, lumbar, sacral, and coccygeal.

Spinal Curves

• The spine has primary and secondary curves.
• The colored areas represent the two primary curves.

Normal Lumbar Vertebra

• The anterior portion is the vertebral body.
• The posterior portion is the neural arch, divided into pedicles and posterior elements.
• The pars interarticularis is the portion of the lamina between the articular processes.

Normal Lumbar Disc

• Discs are tough fibrous shock-absorbing pads between lumbar vertebrae.
• They account for 20-25% of the vertebral column's total length.
• Cartilaginous endplates hold the discs in place.
• Each disc is composed of an outer tire-like band (annulus fibrosus) surrounding a gel-like substance (nucleus pulposus).

Intervertebral Disk and ROM

• Intervertebral discs allow vertebra tilting, increasing range of motion (ROM) at the inter-body joint.
• Without discs, only translational motions are possible.

Effect of Posture on Discal Pressure

• Posture significantly impacts discal pressure.
• Disc pressure varies by position: Sleeping, sitting, leaning, etc.
• Standing positions are used as the comparative baseline for compression.

Lumbar Nerve Roots

• Nerve roots exit through small canals between vertebrae and discs.
• Pain and other symptoms can result from damaged discs pressing on spinal canals or nerve roots (radiculopathy).

Lumbar Ligaments

• Ligamentum flavum limits flexion,
• Supraspinous and interspinous ligaments limit flexion.
• Intertransverse ligaments limit contralateral lateral flexion.
• Anterior longitudinal ligament limits extension and reinforces anterior aspect of annulus fibrosus.
• Posterior longitudinal ligament limits flexion and reinforces posterior aspect of annulus fibrosus.
• Capsule of facets strengthens and supports the apophyseal joint.
• Iliolumbar ligament stabilizes L5/S1.

Lumbar Vertebrae Movements

• Movements occur in three planes: Sagittal (flexion/extension), Coronal (side bending), and Transverse (rotation).
• During flexion, anterior tilting and gliding cause compression of the anterior annulus fibrosus and stretching of the posterior annulus fibrosus. The nucleus pulposus moves posteriorly.
• During extension, superior vertebras tilt and glide posteriorly over inferior vertebras, stretching the anterior annulus fibrosus and bulging the posterior portion of the disc. The nucleus pulposus moves anteriorly.

Regional Differences in Lumbar Spine Movements

• The largest lateral flexion and axial rotation happen in the mid lumbar region (L2-L3).
• Lower lumbar levels (L4-S1) are primarily involved in flexion and extension.

Facet Joints Direction During Lumbar Motions

• Superior facets face medially and backward (concave).
• Inferior facets face laterally and forward (convex).

Lumbar Facet Joint Dysfunction

• Facet joint pathology is a common cause of chronic low back pain, it is aggravated by lumbar extension, but relieved by lumbar flexion.
• Pain commonly occurs acutely with extension and rotation tests.

No Localizing Neurologic Symptoms (Low Back Pain)

• The pain is usually non-radiating.
• Sudden-onset back pain (increasing intensity) is associated with disc lesions.
• Facet joint manipulation often provides relief.

Risk Factors for Low Back Pain

• Age, heavy manual labor, repetitive lifting/twisting, posture, whole-body vibration, monotonous work, poor physical fitness / strength, smoking, work-related psychological factors contribute to low back pain.

Spondylolysis

• Defined as a stress fracture of the pars interarticularis (area between inferior and superior articular facets).
• Common in young people, especially gymnasts, due to repetitive stress on the spine.
• Unilateral or bilateral defects are possible.
• Symptoms often include low back pain without neurological deficits.

Spondylolisthesis

• The slipping of a vertebra from its normal position.
• Often as a progression of spondylolysis.
• Characterized by one vertebra sliding anteriorly relative to the vertebra immediately below.
• Most common in women and adolescent/young gymnasts.

Stages of Low Back Pain

• Acute: less than 4 weeks. Sub-acute: 4 to 12 weeks. Chronic: beyond 12 weeks.

Red Flags for Low Back Pain

• Age (<20 or over 70), history of trauma, constant and progressive pain, history of carcinoma, steroids use, fever, infection, systemic illness, weight loss, bowel/bladder incontinence or loss of motor functions are all red flags that suggest serious underlying pathology.

Nerve Root Impingement:

• Narrowing of intervertebral foramen can cause nerve root impingement, conditions include: stenosis, facet joint degeneration, herniated intervertebral disc.

Degenerative lumbar Spinal Canal Stenosis

• Stenosis is a narrowing of the space in the spinal canal.
• Symptoms may include pain that worsens with standing or walking and improves with forward flexion (neurogenic claudication).
• It is not typically a problem for young people and more common in older people.

Causes/Types of Lumbar Spinal Stenosis

• Congenital (idiopathic), Spondylosis (bone spurs), Spondylolisthesis, Scoliosis, Ossification of PLL, Hypertrophied facet joints, Hypertrophied ligamentum flavum, and herniated disc are examples of types of lumbar spinal stenosis.

Lumbar Disc Herniation

• Rupture of the nucleus pulposus through the annulus fibrosus.
• Common at the L4-L5 or L5-S1 levels.
• 75% of cases resolve spontaneously within 6 months.
• Symptoms usually include leg pain and paresthesia more than back pain.

MRI Lumbar Images

• MRI images show L5-S1 disc extrusion, while L4-5 has a protrusion contained by PLL.

Lumbar Spondylosis (Disc Degeneration)

• Various degenerative changes in the spine.
• Age-related, gradual onset, and often unknown cause. The black disc in this MRI indicates the disc has low water content, common with the degeneration of discs.

Loss of Water in Nucleus Pulposus (Disc Degeneration)

• A loss of water in the nucleus pulposus leads to the reduction of its cushioning ability.
• Disc bulges, and scar tissue formation may occur in the annulus fibrosus.
• The intervertebral space narrows (approx. facet joints).

Lumbar Musculature

(Images show/list muscles: psoas major, transversus abdominus, rectus abdominus, quadratus lumborum, latissimus dorsi, iliolcostalis, longissimus, multifidus, lumbar fascia, etc.)

Posture and Movement

• Posture is essential for assessing discal pressure and lumbar spine health.
• Various positions, including sitting, standing, and leaned positions may influence compression or pressure.

Questions