Mechanical Low Back Pain

August 13th, 2022

Lumbar Spine (Low Back)

  • low back portion of articulating spine (vertebral column) normally composed of five vertebral segments with muscles (large and superficial as well as small and deeply situated) controlling global movement and segmental stability, locally stabilizing ligaments, and mobility-enhancing, force-attenuating discs
  • lumbar spine poised immediately atop 'foundation' of pelvis with consequent direct mechanical interrelation

Mechanical Low Back Pain

  • clinically complex and multifactorial condition; predisposing factors include: excess body weight (increased compression on spinal structures); tight thigh muscles, e.g., hamstrings and piriformis, (constriction of lumbo-pelvic mobility); sedentary lifestyle (sustained loading of spinal structures resulting in ~17% increase in load when sitting versus standing or walking); poor core muscle recruitment and control (lack of lumbo-pelvic stability as it is the small and deeply-situated muscles that provide local stability); and poor postural habits and ergonomic considerations (imbalance of dynamic and static forces acting on lumbar spine)
  • Mechanical low back pain (LBP) represents 85% of all cases of LBP; very high incidence (70% of general population will experience at least one episode of disabling LBP); leading cause of time off work and largest expenditure of compensation claims for workers
  • causes (greatest to least): precipitating event (acute trauma/strain, e.g., MVA, fall, most common cause is lumbar muscle, ligament, tendon strain after bend/lift/twisting activity); cumulative, e.g., work-related, trauma; facet joint arthritis; acute or cumulative/repetitive disc loading or shearing disorders (e.g., bulge, herniation); spondylosis (degenerative condition ultimately resulting in lack of local spinal mobility or fusion), stenosis (narrowing of lumbar spinal column +/- pressure on nerve roots); spondylolisthesis (forward displacement of vertebra); scoliosis (lateral curvature of spine)
  • onset typically rapid and acute pain with varying degrees of severity; often intensifies on second or third day as spasm and/or inflammation increases
  • characterized by acute localized back pain (central or predominantly on one side); may radiate into buttock and leg of corresponding side

Physical Therapy Treatment

  • application of electrotherapeutic modalities and ice to reduce inflammation, acute muscle spasm, and pain in acute stage or heat to ease subacute muscle tightness
  • manual therapy directed to lumbar spine and/or pelvis to alleviate pain, increase joint stability/mobility, and restore function
  • spinal decompression by way of lumbar traction, as indicated
  • early intervention and education: specific exercises (stretch, strengthen, core recruitment and control) demonstrated and assigned at early stage of condition to significantly reduce residual and recurrent symptoms (e.g., pain)
  • myofascial soft tissue release


  • high percentage of resolution within a few weeks of commencing treatment

Physio Note: Joint Protection (including Core Recruitment)

Your physical therapist can provide instruction and education regarding muscle length, strength, recruitment and control; also, posture, ergonomics, and biomechanics

Core exercises come in many forms: exercise ball, mat exercises, pilates, yoga, and tai chi can all be useful. Your therapist can individualize a program for you