Chronic Low Back Pain: Bio-Psycho-Social Model In Physiotherapy Treatment

Low back pain is termed chronic when the pain lasts for more than 3 months. The literature and clinical practice show that chronic low back pain (CLBP) is a multi-faceted problem and requires a multi-dimensional approach in its treatment (Elvey and O’Sullivan, 2004; Mc Carthy et al, 2004; Waddell, 2004).

Factors Contributing To Chronic Low Back Pain

The factors that require consideration when dealing with chronic low back pain (CLBP) include:

  1. Patho-anatomical factors – structural pathology, identify peripheral pain generator e.g. discs, z joints, neural tissues or myofascial
  2. Physical factors- ergonomics, lifestyle, strength/conditioning, motor control, mechanisms of injury, adaptive/maladaptive motor response
  3. Pain (Neurophysiological factors)-peripheral sensitization, central sensitization, sympathetic nervous system activity
  4. Psychological factors- personality type, beliefs and attitudes, emotions such as anger/fear/anxiety/depression and coping strategies such as being a confronter versus an avoider
  5. Social factors- compensation- financial or emotional, relationships with family, friends and at work, cultural factors, support structure, work structure, socio-economic factors. (O’Sullivan 2005)

The relative contribution of the different factors and their dominance associated with CLBP will differ for each person. The role of the physiotherapist through clinical reasoning is to determine which factors are dominant in the patient and whether the patient has adapted to the disorder positively or negatively.

Categorising Chronic Back Pain Disorder

To broadly categorize chronic back pain disorder, a classification system of back pain disorder was proposed by O’Sullivan (2005). The classification indicates the possible mechanism of pain, and hence a targeted approach in its treatment.

Only 15% of those suffering from chronic low back pain (CLBP) have a specific pathology associated with their disorder (Nachemson 1999) and the remaining 85% have no radiological basis to their pain condition. This group represents a large group of “unresolved tissue strains and sprains”. The challenge here is to identify the underlying pain mechanism. Moreover, the diagnosis needs to be based on a different criterion other than radiology. It needs to be based on a bio-psycho-social model.

Most of the CLBP patients we see in clinical practice belong to the non-specific low back pain subgroup with peripherally mediated pain. Within this subgroup, there are 2 types of impairment disorders 1) Control impairment disorder and 2) Movement impairment disorder.

1. Control Impairment Disorder

In this subgroup, it is primarily a peripheral nervous system disorder resulting from a loss of functional control of a spinal segment in one or more directions. The loss of motor control can be in flexion, extension, lateral shift or multi-direction. In this newsletter, we will discuss the flexion pattern.

In the flexion pattern, the pain disorder is a result of a loss of motor control of the lumbar segment into flexion. This is associated with a loss of control of the segmental lumbar lordosis. This presentation:

  • is found in men more often than in women
  • have a history of flexion injury and repetitive strain
  • pain is a result of flexion/rotational activities and postures
  • pain dissipates in lordotic/extended postures

On objective assessment:

  • there is a loss of segmental and regional lordosis in the lumbar spine in sitting, standing and bending
  • Associated increased tone in upper lumbar and lower thoracic Erector Spinae muscles
  • Pain is a result of flexion loading. It is relieved by controlling segmental lordosis in a provocative task
  • Generates extension through the thorax

Treatment for the flexion pattern subgroup

  • To train and isolate anterior pelvic rotation. There are 2 aspects to this
    1. Learning to dissociate the pelvis and the lumbar spine from the thoracic spine. Ensure isolated lumbar segmental extension without the involvement of the thoracic erector spinae.
    2. To train the localized lumbar spine extensors like the multifidus.
  • To identify and retrain the provocative postures and movement patterns. An example of this is to train neutral lordosis (with a relaxed thorax) with forward trunk control loading through a functional task. An example is a sit to stand. The lordosis should be maintained throughout the movement. Need to look at training endurance of the lumbar spine extensors in static postures.
  • Functional reintegration. To increase the speed, load and complexity of the training as required which will depend on individual demands.
  • Cardio vascular exercise to improve overall fitness.

2. Movement Impairment Disorder

In the movement impairment disorder, the disorder is derived from the peripheral nervous system associated with a painful loss of normal physiological movement of a spinal segment in one or more directions. In this group of clients, history supports the notion that normal movement was not restored following acute pain episode. This is a result of fear avoidance behaviour, belief that pain is damaging and has been advised not to provoke pain. These are with people with insignificant radiological findings and are unable to differentiate a stretching discomfort from a physiological/structural pain. They present with muscle guarding in the direction of the pain. Symptoms dissipate through gentle activity, heat and stretching. Again, this painful loss of normal physiological movement can occur in all directions. In this article, we will look at the active extension pattern.

In the active extension pattern, the disorder is as a result of the lumbar segment “actively” held into extension.

This presentation:

  • is found more commonly in women than men
  • injury is a result of an extension or forward bending in the presence of hyperextension of the lumbar spine
  • Pain is a result of extension and forward bending activities and relieved with lumbar flexion
  • On objective assessment:

Posture is hyper lordotic in sitting and standing

  • There is no flexion relaxation of the erector spinae in late forward bending
  • Segmental hinging in backward bending (usually found in L5/S1 region)
  • Pain is a result of extension loading
  • Pain dissipates by reducing spinal lordosis

Treatment for active extension pattern

  • Reduce tone and train relaxation of the spinal extensors
  • Focus on lower abdominals and gluteal control
  • Train pelvic tilt to encourage lumbar spine flexion
  • Train postures and functional activities with reduced anterior pelvic tilt and lordosis

This classification system-and-treatment approach is relatively recent. However, there is evidence to support the effectiveness of this approach (O’Sullivan et al, 1997; Dankaerts et al 2006).


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  5. O’Sullivan P, Twomey, L and Allison,G. Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiological diagnosis of spondylosis and spondylolythesis.Spine22(24) (1997):2959-2967
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Chronic Low Back Pain