Non Specific Low Back Pain

Definition

Mechanical low back pain is the general term that refers to any type of back pain caused by strain on muscles of the vertebral column and abnormal stress.

Clinically relevant anatomy

• Bony: at each level of the vertebrae there’s a 3-joint complex, namely 2 facet joints and a disc interposed between 2 vertebra. Joint inflammation and degeneration is caused by rotational load of the facet joints and the disc weight-bearing transfers.
• The nucleus of the disc, facet joint capsule, anterior and posterior longitudinal ligaments, muscles, .. are the causes of the most pain.
• There are 2 important muscular groups: The anterior group: abdominal and psoas muscles.

                                                                             The posterior group: erector spinae, profundi and intersegmental muscles.

Epidemiology/etiology

Mechanical low back pain is defined as pain secondary to:

• Traumatic injury
  
• Lumbar sprain or strain: degenerative disease, discs, facet joints, diffuse idiopathic skeletal hyperostosis[[|]]
  
• Spondylolysis, Spondylolisthesis
  
• Disc Herniaton
  
• Spinal Stenosis
  
• Osteoporosis with Compression fracture (Lumbar compression fracture)
  
• Congenital disease: severe Kyphosis, severe Scoliosis
  
• Paget's Disease

The surrounding ligaments, muscles and facet joints may become irritated and inflamed. People with mechanical back pain experience pain primarily in the lower back, the pain can also radiate to the knees, thighs or buttocks. This is called sciatica, namely nerve pain from irritation of the sciatic nerve.

There are 3 types of mechanical low back pain:

• Acute
  
• Subacute
  
• Chronic
  

Characteristics/clinical presentation

This low back pain is usually aggravated by:

• Long levered activities
• Lifting heavy objects
• Levered postures (bending forward)
• Static loading of the spine (prolonged sitting or standing)

Testing:

The following tests are used when evaluating low back pain.

• Observe the patient walking into the office or examining room
• Observe the patient during the history-gathering portion of the visit for development, nutrition, deformities, and attention to grooming
• Measure blood pressure, pulse, respirations, temperature, height, and weight
• Inspect the back for signs of asymmetry, lesions, scars, trauma, or previous surgery
• Measure lumbar range of motion (ROM) in forward bending while standing (Schober test)
• Palpate the entire spine to identify vertebral tenderness that may be a nonspecific finding of fracture or other cause of low back pain
• Test for manual muscle strength in both lower extremities.
• Test for sensation and reflexes
• Imaging studies: Persistent pain may require CT scanning, diskography, and 3-phase bone scanning; electromyography and nerve conduction studies can help in the evaluation of neurologic symptoms or deficits

Diagnostic procedures

It’s difficult to reliably identify by diagnostic testing. These typically involve processes in the muscles and/or ligaments.

Differential diagnoses

• Discogenic back pain 
  
• Cauda Equina Syndrome
  
• Fracture (compression, spinosus process, stress fractures of pars)
  
• SI dysfunction
  
• Non-back pain infection (AAA, Pancreatitis, posterior penetrating ulcer and pyelonephritis)
  
• Metastatic disease (prostate, renal cell, thyroid, breast)
  

Examination

• Paraspinal muscle tenderness
• No bony tenderness
• Back pain with passive knee-to-chest stretch  
• Limited ability to forward bending as a resullt of limited ROM  
• Muscle spasm
• Negative discogenic exam

Medical management

Mechanical low back pain (LBP) is not a life-threatening illness. Unfortunately, it does have a far-reaching impact on medical care expenditures for injured workers.

Pharmacological interventions for the relief of low back pain (LBP) include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), topical analgesics, muscle relaxants, opioids, corticosteroids, antidepressants, and anticonvulsants.

Acetaminophen remains one of the best first-line treatments of acute LBP.

Physical therapy management

The conservative treatment in the initial phase is ice massage followed by passive knee-to-chest stretch (one leg at a time then both legs together). Also daily walks followed by stretching, electrical stimulation and iontophoresis are recommended in this phase. It’s important to identify possible causes and to correct harmful activities and attitudes, to avoid further back pain problems.

In the second phase it’s necessary to continue the pain management and to be alert for ‘red flags’. The rehabilitation program exists out of stretching of the hamstrings and back (knee-chest), strengthening of back flexors and extensors and core strengthening.

Patients should be taught several correct and comfortable positions and postures (during sleeping, sitting, lying, standing, walking and lifting techniques) that are safe for the spinal structures.