Definition
Non-specific or mechanical LBP can be defined as pain, tension, soreness and/or stiffness in the lower back region. It is evoked by noxious stimulation of structures in the lumbar spine (Bogduk, 2009). The lower back is commonly defined as the area between the bottom of the rib cage and the buttock creases. Some individuals with non-specific LBP (NSLBP) may also feel pain in their legs, but the low back pain usually predominates.
Cause
In approximately 90% of patients with LBP no specific patho-anatomic cause can be found (CSAG,1994). Several structures in the back including the joints, discs, muscles, nerves, vascular and connective tissues may contribute to the symptoms but it is often not possible to identify a specific cause.
Prevalence
It has been estimated that 80% of the population will be affected by LBP at some point in their lives. Around 20% of people with LBP will consult their GP about LBP and this equates to 1 in 5 of the general population. The cost of this low back pain epidemic to society is significant with the loss of over 180 million days per year through sickness absence at an annual cost of approximately £6 billion. Despite this the condition only receives 1.8% of NHS spending (CSP media release, 2004).
Presentation
- Symptoms variable within the lumbar spine and lower limb
- Postural changes due to accommodation of the pain may be present
- Restricted and painful back movements
- Possible antalgic gait pattern
It is predominantly a self-limiting condition with 75-90% of primary care presentations improving within 6 weeks irrespective of the type of intervention (Jackson, 2001). However, in spite of this, 60 – 80% of patients will experience a reoccurrence of LBP in the year following their first episode (Hides et al., 1996).