Anatomy and Physical Examination of the Lower Back

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

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

4. 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

5. 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

6. 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

7. “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

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

9. 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

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

12. Ligaments • Anterior longitudinal ligament • Posterior longitudinal ligament • Interspinous ligament • Supraspinous ligament • Ligamentum flavum

14. 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

16. 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

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

20. 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

22. 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

25. 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

30. ANTERIOR PALPATION

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

37. Range of Motion • Flexion • Extension • Lateral Bending • Rotation

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

42. 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

43. 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

44. 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

45. L2, L3, L4 testing

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

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

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