Mechanical Back Pain

Mechanical back pain is the general term that refers to any type of back pain caused by placing abnormal stress and strain on muscles of the vertebral column. Typically, mechanical pain results from bad habits, such as poor posture, poorly-designed seating, and incorrect bending and lifting motions.

Other Names

  • Myofascial back pain
  • Lumbago
  • Lumbosacral strain
  • Lumbosacral sprain
  • Lumbar strain
  • Lumbar sprain
  • Thoracic strain
  • Thoracic sprain
  • Non-specific low back pain
  • Lumbar contusion
  • Musculoligamentous Strain

Pathophysiology

  • This page refers to the nonspecific mechanical back of the lumbar and thoracic spine
    • Generally defined as back pain not attributable to a known specific pathology
    • There are many causes including strain, sprain, contusion, etc
    • It May be acute or chronic
    • If you suspect a structural problem, please refer to that specific diagnosis
  • Healthcare Utilization
    • Picavet et al: less than 1/3 of patients with low back pain consulted their family doctor the previous year
    • Weiser et al: 22.8% of patients sought medical care
  • Prevalence varies based on the definition
    • Ozgur et al: 8% when low back pain was defined as requiring sick leave, 45% when it lasted at least a day
    • Prevalence rates of low back pain in athletes range from 1% to 40%
    • In general, prevalence rates are thought to be lower in athletes than nonathlete
  • Back injuries occur in 10-15% of athletes
  • Mechanical or nonspecific back pain by definition are a symptom of an unknown cause or we currently have no reliable way to identify the pathology
  • Repetitive trauma and overuse are common causes of chronic mechanical low back pain, which is often secondary to workplace injury
  • Frequently, lesions identified on MRI can not be reliably established as the cause of low back pain
  • Inflammation is one proposed pathophysiological entity
    • Tumor necrosis factor-alpha (TNFa) was found to be significantly higher in patients with low back pain compared to controls
    • Other imnplicated factors include nerve growth factor, substance P production
  • Mechanical factors are implicated
    • No clear independent, a causal association with occupational sitting, awkward postures, standing and walking, manual handling or assisting patients, pushing or pulling, bending and twisting, lifting, or carrying
  • Athletes
    • The majority of low back pain in athletes is from a benign source
    • A muscle strain may be the most common cause of low back pain in college athletes
  • Degenerative Disc Disease
    • OR for nonspecific back pain between 1.9 and 2.18

Causes

  • History of previous back pain
    • Strongest risk factor for future back pain[
  • Obesity
  • Disuse
  • Physical deconditioning
  • Tobacco Use Disorder
  • Genetic
    • Based on twin studies
  • Physical Activity
    • U-shaped relationship with back pain associated with extremes on either end
  • Sports
    • Wrestling
    • Gymnastics
  • Fractures
    • Compression Fracture
    • Burst Fracture
    • Chance Fracture
    • Spinous Process Fracture
    • Transverse Process Fracture
    • Rib Fracture
    • Sacral Stress Fracture
  • Neurological
    • Lumbar Radiculopathy
    • Cauda Equina Syndrome
    • Sciatica
  • Musculoskeletal
    • Mechanical Back Pain
    • Scoliosis
    • Kyphosis
    • Herniated Disc
    • Facet Joint Pain
    • Sacroilliac Joint Pain
    • Spinal Stenosis
    • Spondylolysis
    • Spondylolisthesis
    • Hyperlordosis
    • Baastrups Disease
  • Autoimmune
    • Ankylosing Spondylitis
  • Infectious
    • Spinal Epidural Abscess
    • Osteomyelitis
  • Pediatric
    • Scheuermann’s Disease

Symptoms

  • General: Physical Exam Back
  • Red Flags[19]
    • Saddle anesthesia
    • Bowel or bladder dysfunction
    • Unexplained weight loss
    • Fevers, chills
    • Night sweats
    • History of violent trauma
    • History of cancer or immunocompromised state
    • Absence of relief after 4 weeks of treatment
    • History of IV drug use
  • Yellow Flags[20]
    • Predict poor response to basic treatment
    • Maladaptive beliefs
    • Poor sleep
    • Mood disorder
    • Job dissatisfaction
    • Poor social support
    • Compensation and/or litigation issues
    • Kinesiophobia
  • History
    • Clarify onset, pain location, severity, timing, aggravating/relieving factors, and radiation
    • Important to consider body habitus, sporting activities, occupation, hobbies
    • Predictors of nerve root compression include dermatomal pattern, pain worse with coughing[21]
    • Predictors of spinal stenosis typically include pain with walking[22]
  • Physical Exam
    • Often normal in mechanical back pain
    • Patients may have localized or point tenderness, worse with range of motion or motor exam
    • Strength, sensation, reflexes and vascular exam should be normal
  • Special Tests
    • Straight Leg Raise Test: Helps evaluate for radicular features
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Diagnosis

  • Do not order imaging on initial evaluation unless there are serious concerns, trauma or red flags
    • This is a category B recommendation[23]
  • American College of Radiology Appropriateness Criteria for low back pain recommends imaging only if[24]
    • No improvement after six weeks of conservative medical and physical therapies
    • There is high suspicion of cauda equina syndrome, malignancy, fracture, or infection
  • The presence of low back pain with radiculopathy is not an indication for early imaging[25]
  • Early imaging is associated with worse overall outcomes and is likely to identify minor, clinically irrelevant abnormalities[24]
  • Jarvik et al compared early MRI to standard radiographs[26]
    • They found both modalities resulted in nearly identical outcomes for primary care patients with low back pain
    • They found no additional benefit to early MRI
    • Also stated it may increase the cost of care because of the increased number of spine operations that patients are likely to undergo
  • A survey by Henschke et al asked 25 red flag questions in the primary care setting and 80% (942/1172) had at least one red flag[27]
    • In this same cohort, only 0.9% (11/1172) had a serious disease
  • Some researchers have opined that in the absence of red flags, one can be 99% certain that serious spinal disease has not been missed[28]
  • Imaging results in increased rates of surgery[29]

Radiographs

  • Standard Thoracic Spine Radiographs, Standard Lumbar Spine Radiographs
  • Appropriate to assess for fracture, bony abnormalities

MRI

  • Appropriate to evaluate the neurological and soft tissue abnormalities
  • MRI abnormalities are very common in asymptomatic individuals (need citation)
    • Do not coincide with the development of back pain
    • Do not predict response to evidence-based therapy for nonspecific low back pain
  • Potential uses for MRI[30]
    • Predictive
    • Diagnostic
    • Assessment of severity
    • Prognostic
    • Assessment of recovery
    • Management planning
    • Therapeutic targeting
    • Occupational screening
  • Indications
    • Progressive neurological deficit
    • A serious underlying condition is suspected

Classification

  • Published work is generally distinguished based on the duration of the episode
    • Acute <6 weeks
    • Subacute 6-12 weeks
    • Chronic >12 weeks

Treatment

Prognosis

  • Most episodes of low back pain are self-limited, not related to serious illness
  • Most patients with acute low back pain recover reasonably quickly and only about 10–15% develop chronic symptoms. (need citation)
  • Australian cohort showed that about a third of patients had not recovered fully after 1 year.
  • In another subset of patients whose pain persisted more than 90 days, only about 40% were pain-free at 12 months
  • Chronic state
    • Most challenging because it tends not to improve with time, consumes most resources
  • Predictors of persistent, disabling low back pain
    • Maladaptive pain-coping behaviours
    • Nonorganic signs
    • Functional impairment
    • Low general health status
    • Presence of psychiatric comorbidities
    • Low recovery expectations
  • Predictors of recovery at 1 year
    • Low levels of fear-avoidance
    • Low levels of functional impairment
  • Most prospective studies have not been able to identify many strong, modifiable risk factors for true first time low back pain
    • Likely in part because of challenges in identifying the cause
  • Physical Exercise
    • Shown to be effective at preventing of developing low back pain
  • Ineffective
    • Stress management, shoe inserts or insoles, back supports, ergonomics or back education, and reduced lifting programs
    • Lift-assist devices, handling advice, training do not appear to be helpful either
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Pharmacotherapy

  • NSAIDS
    • Effective for short-term relief of acute and chronic low back pain without radiculopathy
    • Cochrane review: No difference between NSAIDs and placebo for radicular symptoms
    • No difference between different types of NSAIDs and between NSAIDs and other commonly used pharmacotherapies, including opioids and muscle relaxants, when used for chronic pain
  • Acetaminophen
    • No evidence that acetaminophen is better than placebo
    • Recommend taking with NSAID for synergy
  • Tramadol
    • Cochrane review found tramadol was more effective than placebo for pain relief and improving function
  • Opiates
    • Short-term effectiveness for pain relief and functioning, but long-term effectiveness and safety are unclear
    • High risk for misuse, diversion, abuse
  • Topimerate
    • Superior to placebo, safe, effective in treatment of chronic low back pain
  • Antidepressants (except duloxetine [Cymbalta])
    • Cochrane review of 10 antidepressant and placebo trials showed no difference in pain relief or depression severity
    • Duloxetine is approved for chronic low back pain and osteoarthritis, evidence supports use in chronic low back pain
  • Lidocaine Patches
    • No more effective than placebo
  • Gabapentinoids
    • Shanthanna et al: Significant adverse effects without demonstrated benefits in patients with chronic low back pain
  • Oral Corticosteroids
    • Eskin et al: No benefit for acute low back pain according to a single randomized controlled trial.
    • A single dose of IM methylprednisolone was no better than placebo for pain relief in patients with acute low back pain
  • Topical Medications
  • Muscle Relaxants
    • Cochrane review: Effective for short term relief of nonspecific acute or chronic back pain
    • High incidence of side effects including drowsiness, dizziness, and other side effects

Physical Modalities

  • Physical Therapy
    • McKenzie method techniques are recommended to reduce the risk of recurrence and the need for health care services.
    • Category B recommendation
  • Spinal Manipulation Therapy (SMT)
    • Encompasses chiropractic, osteopathic and massage therapy
    • Moderate evidence of short-term pain relief with acute low back pain treated with SMT
    • Chronic low back pain showed moderate improvement with SMT, which is as effective as NSAIDs, more effective than physical therapy
    • Patients with mixed acute and chronic low back pain had better pain outcomes in the short and long term compared with McKenzie therapy, medical care, management by physical therapists, soft tissue treatment, and back school
    • Cochrane review: more effective than sham therapy for reducing pain, improving activities of daily living
  • Osteopathic Manipulation
    • Systematic review: safe, effective for reducing symptoms of both acute and chronic low back pain
  • Accupuncture
    • Cochrane review: more effective for pain relief, functional improvement than sham treatment in the short term only for chronic back pain[54]
    • Not more effective than other conventional or alternative treatments, likely a useful adjunct to primary treatments
  • Dry Needling
    • Cochrane review: not more effective than other conventional or alternative treatments</ref name=”Ref3″>
    • Likely a useful adjunct to primary treatments
  • Massage Therapy
    • Cochrane review: acute, sub-acute and chronic LBP had improvements in pain outcomes with massage only in the short-term follow-up only[55]
    • Functional improvement was observed in participants with sub-acute and chronic LBP when compared with inactive controls, but only for the short-term follow-up
  • Therapeutic Ultrasound
    • There are no systemic reviews for ultrasound
  • Low-Level Laser Therapy (LLLT)
    • Cochrane review of 7 small studies: insufficient data to either support or refute the effectiveness of LLLT for the treatment of low back pain
    • When combined with NSAIDS, Konstatninovic et al found LLLT improved movement, reduced pain intensity and disability, improved quality of life when compared to controls or sham LLLT
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Other Modalities

  • Exercise Therapy
    • In chronic back pain, slightly effective at decreasing pain, improving function
    • In acute low back pain, exercise therapy was no better than no treatment or conservative treatments.
  • Cold Therapy
  • Heat Therapy
    • Cochrane review: moderate evidence supporting superficial heat therapy as reducing pain and disability in patients with acute and subacute low back pain
    • The addition of exercise further reduces pain and improves function
    • Benefit greatest in first week following injury
  • Cognitive Behavioral Therapy
    • In adults with chronic LBP, mindfulness-based stress reduction (MBSR) and/or cognitive-behavioral therapy (CBT) resulted in greater improvements in back pain, functional limitations at 26 weeks compared to usual care
    • No difference between MBSR and CBT
  • Yoga
    • Systematic review: effective for short term (strong evidence), long term (moderate evidence) for chronic low back pain
  • Transcutaneous Electrical Nerve Stimulation (TENS)
    • Not consistently more effective than placebo in the treatment of chronic low back pain.
  • Multidisiplinary Rehabilitation
    • Defined as a multimodal approach including a physical component, a psychological component, and a social/work component
    • Cochrane review: more effective than usual care for decreasing pain, disability in patients with chronic low back pain
  • Patient Education
    • Sometimes termed ‘back school’
    • Cochrane review: strong evidence that 2.5-hour educational session is more effective for return to work, long term pain in patients with acute, subacute back pain
    • Same study found less intensive patient education is no more effective than no intervention
  • Lumbar Brace

Procedures

  • Corticosteroid Injections
  • Prolotherapy
    • Cochrane review: not effective as sole treatment for chronic LBP
    • When combined with other interventions, may help improve chronic LBP, disability
    • In both acute and chronic mechanical back pain, it is important to set expectations and goals for the patient
    • The problem should be discussed with the patient including the difficulty in finding a clear cause for their back pain
    • Advice should embrace exercise, health-promoting activities and not “bed rest”
    • Generally not recommended
      • Intradiscal Electrothermal Therapy
      • Percutaneous Intradiscal Radiofrequency Thermocoagulation
      • Radiofrequency Facet Joint Denervation

Operative

  • Consider surgical referral in patients with disabling low back pain impacting the quality of life for more than 1 year
  • The role, if any, for surgery in chronic, non-specific low back pain is limited and its overuse has been heavily scrutinized
  • Studies have compared intensive rehab with spinal fusion
    • Similar clinical outcomes
    • More complications, more expenses are associated with surgery

Rehab and Return to Play

Rehabilitation

  • 3 phase approach described by Ligia et al.
  • Acute /subacute phase
    • Generally includes a few days of rest, icing, ultrasounds, iontophoresis, laser therapy and other modalities
    • Consider aerobic activity in the pool (subacute phase)
    • Emphasis on isometric core strengthening
  • Rehabilitative phase
    • Core stabilization
    • Depending of the pathology mechanism, we shall promote flexion or extension program
    • Begin the closed chain strengthening and co-activated muscular coordination for improving muscle balance
  • Sport-specific rehabilitation
    • Prepare the athlete to return to sporting activities
    • Should be a specific program for individual sport
    • Emphasis on decreasing stress forces at the back, to maintain the static of the spine and decrease the disc injuries.
    • The goal is to minimize recurrence and improve sports performance.

Return to Play

  • Not a lot of evidence to guide return to play
    • If no structural injury is suspected or identified, athletes can often play through pain
  • Experts agree athletes should have full active ROM before full RTP