Remote manifestations of low back problems; sciatica and extent of leg involvement – a statistical clinical study

Abstract

Aim: To study the significance of lower limb pain in low back conditions.

Patients and Methods: Data from a previously reported industrial study (6886 records) and clinical study (301 cases) were revisited. The duration of episodes, pain drawings, diagnostic cluster analyses and pain severity scaling were all used to investigate sciatica and the extent of leg pain associated with various forms of low back pain.

Results: The average duration of an episode of sickness absence from work certified as sciatica was 16.9 days, whereas lumbago was shorter at 9.3 days. Pain radiating down the leg beyond mid-calf contributed modestly to the classification coefficients for diagnosing the prolapsed intervertebral disc subgroups (8.2 and 7.3), but also to a lesser degree (6.5 to 3.5) with the other conditions. The extent of pain radiation down the leg showed highly significant (P = 0.0000) but weak correlations with other measures of severity such as subjective pain scale (r = 0.20) and disability (r = 0.22). Sciatica beyond mid-calf and neurological deficit were of poor short-term prognosis.

Conclusions: Sciatica beyond mid-calf can be of some limited diagnostic and prognostic use. The variation of extent of radiation of leg pain was a weak indicator of the severity of the back condition and this could be used as an outcome criterion.

Keywords:

• LOW BACK PAIN
• LUMBAGO
• SCIATICA
• EXTENT
• DIAGNOSIS
• SEVERITY