Anatomy and Physical Examination of the Lower Back Sports Medicine Fellowship Uniformed Services University of the Health Sciences

Objectives Review the functional anatomy of Lumbar spine Review Physical Examination of LS spine Correlate clinico-pathologic dx with pertinent physical findings

Epidemiology of back pain The most common musculoskeletal disorder in industrialized societies Second only to common cold as cause of lost work time Estimated that ~ 80% of population will experience at least one disabling episode of back pain at some time during their lifetime The most common cause of disability in persons under the age of 45

Epidemiology of back pain (cont.) When compensation from lost work, long-term disability, and medical and legal expenses are considered, is the most costly of all medical dx’s

PATIENT HISTORY “OPQRSTU” Onset Palliative/Provocative factors Quality Radiation Severity/Setting in which it occurs Timing of pain during day Understanding - how it affects the patient Onset Palliative/Provocative factore Quality Radiation Severity/Setting in which it occurs Timing of pain during day Understanding - how it affects the patient

“Red Flags” in back pain Hx of cancer Unrelenting nocturnal pain Weight loss Fever, chills, night sweats Age < 15 or > 50 Neurologic deficits Decreased motor and/or sensory innervation Urinary and/or fecal incontinence

Anatomy Vertebra Body, anteriorly Functions to support weight Vertebral arch, posteriorly Formed by two pedicles and two laminae Functions to protect neural structures

Vertebral arch 7 vertebral processes arise from vertebral arch 3 lever-like processes - provide attachments sites for ligaments and muscles Spinous process 2 Transverse processes 4 articular processes Arise from junction of pedicle and laminae

Vertebral Arch Space enclosed by body and vertebral arch is the vertebral foramen Successive vertebral foramen form the vertebral canal

Ligaments Anterior longitudinal ligament Posterior longitudinal ligament Interspinous ligament Supraspinous ligament Ligamentum flavum

Intervertebral Disc Most common site of back pain Normally comprises ~ 25% of length of spine Consists of a central nucleus pulposus Reticulated and collagenous substance Composed of ~ 88% water Annulus fibrosus Consists of concentric lamellae of fibrocartilage fibers arranged obliquely With each layer, they are arranged in opposite directions

Facet Joint Formed by articulation of inferior and superior processes of subsequent vertebrae Orientation in lumbar spine is toward sagittal plane, allowing flexion and extension but limiting rotation of the lumbar vertebrae Helps to prevent anterior movement of superior vertebra on inferior vertebra Articular surfaces are made up of noninnervated articular cartilage Capsule and synovial membrane are innervated with pain receptors

Physical Examination Inspection Palpation Bony Soft Tissue Range of Motion Neurologic Examination Special Tests

Inspection Observe for areas of erythema Infection Long-term use of heating element Unusual skin markings Café-au-lait spots Neurofibromatosis Hairy patches (Faun’s beard) Lipomata Spina bifida

Inspection (cont.) Posture Shoulders and pelvis should be level Bony and soft-tissue structures should appear symmetrical Normal lumbar lordosis Exaggerated lumbar lordosis is common characteristic of weakened abdominal wall

Bone Palpation Palpate L4/L5 junction (level of iliac crests) Palpate spinous processes superiorly and inferiorly S2 spinous process at level of posterior superior iliac spine Absence of any sacral and/or lumbar processes suggests spina bifida Visible or palpable step-off indicative of spondylolisthesis

Common area of pain due to low back sprains or the avulsion of a tendon from the posterior superior iliac spines

ANTERIOR PALPATION ANTERION PALPATION Anteriorly, umbilicus lies at L3-L4 disc space, the point where aorta divides into common iliacs Anterior portions of L4, L5, and S1 vertebral bodies and discs are palpable below the aorta’s division

Soft Tissue Palpation 4 clinical zones Midline raphe Paraspinal muscles Gluteal muscles Sciatic area Anterior abdominal wall and inguinal area

Palpate as a unit on either side of midline Note any tenderness, spasm, defects, or dissimilarity

Sciatic nerve exits pelvis thru greater sciatic foramen under the piriformis muscle Midway between the greater trochanter and ischial tuberosity To palpate the sciatic nerve, have pt flex hip, and locate the midpoint Herniated disc or lesion compressing the nerve roots can cause tenderness to palpation

Have pt perform abdominal crunch, then palpate each segment of rectus abdominis, noting any weakness or deficit Abdominal muscles are segmental and receive segmental innervation Pain in inguinal area usually indicates pathology in hip joint

Range of Motion Flexion Extension Lateral Bending Rotation

Flexion - 80º Extension - 35º Side bending - 40º each side Twisting - 3-18º

Neurologic Examinaion Includes an exam of entire lower extremity, as lumbar spine pathology is frequently manifested in extremity as altered reflexes, sensation and muscle strength Describes the clinical relationship between various muscles, reflexes, and sensory areas in the lower extremity and their particular cord levels

Neurologic Examination (T12, L1, L2, L3 level) Motor Iliopsoas - main flexor of hip With pt in sitting position, raise thigh against resistance Reflexes - none Sensory Anterior thigh

Neurologic Examination (L2, L3, L4 level) Motor Quadriceps - L2, L3, L4, Femoral Nerve Hip adductor group - L2, L3, L4, Obturator N. Reflexes Patellar - supplied by L2, L3, and L4, although essentially an L4 reflex and is tested as such

L2, L3, L4 testing

Neurologic Examination (L4 level) Motor Tibialis Anterior Resisted inversion of ankle Reflexes Patellar Reflex (L2, L3, L4) Sensory Medial side of leg

L4 LEVEL Motor: Tibialis Anterior -Resisted inversion of ankle Reflexes: Patellar Reflex Sensory: L4 dermatome covers medial side of leg

Neurologic Examination (L5 level) Motor Extensor Hallicus Longus Resisted dorsiflexion of great toe Reflexes - none Sensory Dorsum of foot in midline

L5 LEVEL Motor: Extensor Hallicus Longus -Resisted dorsiflexion of great toe Reflexes - none Sensory: Dorsum of foot in midline

Neurologic Examination (S1 level) Motor Peroneus Longus and Brevis Resisted eversion of foot Reflexes Achilles Sensory Lateral side of foot

S1 LEVEL: Motor: Peroneus Longus and Brevis -Resisted eversion of foot Reflexes: Achilles Sensory: Lateral side of foot

Special Tests Tests to stretch spinal cord or sciatic nerve Tests to increase intrathecal pressure Tests to stress the sacroiliac joint

Tests to Stretch the Spinal Cord or Sciatic Nerve Straight Leg Raise Cross Leg SLR Kernig Test

Test to increase intrathecal pressure Valsalva Maneuver Reproduction of pain suggestive of lesion pressing on thecal sac

Tests to stress the Sacroiliac Joint Pelvic Rock Test FABER Test

Flexion A- Bduction External Rotation

Non-organic Physical Signs (“Waddell’s signs”) Non-anatomic superficial tenderness Non-anatomic weakness or sensory loss Simulation tests with axial loading and en bloc rotation producing pain Distraction test or flip test in which pt has no pain with full extension of knee while seated, but the supine SLR is markedly positive Over-reaction verbally or exaggerated body language Waddell, et al. Spine 5(2):117-125, 1980.

Hoover Test Helps to determine whether pt is malingering Should be performed in conjunction with SLR When pt is genuinely attempting to raise leg, he exerts pressure on opposite calcaneus to gain leverage

Common Causes of Low Back Pain Muscular spasm, strain Ligament sprain Spondylosis Herniated nucleus pulposus Facet joint dysfunction Spondylo-lysis or -listhesis Seronegative spondyloarthropathies

Clearing up the terms Spondylosis Degenerative joint disease affecting the vertebrae and intervertebral disc Spondylolysis Fracture in pars interarticularis Spondylolisthesis Displacement of one vertebra on another

Disc rupture and herniation

Spondylo-lysis and -listhesis

Facet joint pain

Ankylosing spondylitis