Low Back Pain
June 14, 2017 at 11:41 AM
It is well known that low back pain has poor correlations to abnormal imaging findings, therefore clinical prediction rules are helpful. Treatment subgroups are obtained through a thorough subjective and objective assessment and are based on Clinical Prediction for Success of Interventions for Managing Low Back Pain (Herbert et al, 2008). Subgrouping has been shown to significantly improve success rates for treatment. We have described subgrouping for low back pain patients briefly below for your interest.
1. EXTENSION EXERCISE GROUP
Studies have found that subgrouping patients dependent on directional preference considerably improves outcomes (Long et al, 2004; Long & May, 2008). Patients that fit into this group have an extension directional preference (worse with sitting/bending/rising, better with walking/standing), and often symptoms below the buttock/s. The most common cause of symptoms in this subgroup is posterior disc prolapse or “derangement”. McKenzie repeated movement assessment is used to confirm whether or not patients will respond to conservative management. If the disc derangement is reducible (ie. the annular wall is intact) the patient’s symptoms will centralize with repeated movements during assessment. Ainaa et al, 2004 found that 91% of patients who displayed the centralization phenomenon had a competent annulus. If the annular wall has been breached and disc material has been extruded the symptoms will not centralize during repeated movement assessment, but may peripheralize. In this event patients can be treated conservatively if they do not want to be assessed for surgical management. In these cases management focuses on maintenance of spinal range of motion/function and avoidance of any nerve root adherence (McKenzie & May, 2003).
2. FLEXION EXERCISE GROUP
To be included in this group patient’s either spinal imaging shows spinal stenosis, they have a clinical diagnosis of spinal stenosis, or have a flexion directional preference (worse with walking/standing, better with sitting/bending). Cook et al, 2011 use five clinical findings to diagnose spinal stenosis – 1) bilateral symptoms; 2) leg pain more than back pain; 3) pain during walking/standing; 4) pain relief upon sitting; 5) Age >48 years. They found that if a patient has ≥4/5 positive findings you can diagnosis spinal stenosis with a specificity of ≥98%. Patients with facet joint pathology also benefit from flexion-based exercises and diagnosis is made by exclusion of disc or SIJ pathology (Laslett et al, 2005). No test other than anaesthetic facet joint blocks has specificity high enough to rule in facet joint pathology at present. Facet joint pathology can, however, be ruled out using the extension rotation test (Cook & Hegedus, 2011; Laslett et al, 2006).
3. STABILISATION EXERCISES
These exercises have been found to be most beneficial for patients <40yrs, with an active straight leg raise of >91 degrees, positive prone instability test, and aberrant movement patterns. When these findings are present the success of intervention increases from 33 to 67% (Hicks et al 2005). Clinical findings of a lack of hypomobility with intervertebral testing plus flexion>53 can also be used to predict radiological instability (Fritz et al, 2005).
Manipulation is generally utilized for patients who have no symptoms below knee, have had symptoms for less than 16-days duration, have a clinical finding of hypomobility in a spinal segment, score <19 on the fear avoidance beliefs questionnaire, and have hip internal rotation of >35 degrees. When these findings are present success rates of manipulation have been shown to increase from 45 to 95% (Flynn et al, 2004; Childs, 2004).
This is rarely required but may be beneficial for patients with symptoms distal to buttock who have nerve root signs present, and who peripheralise with extension based exercises. These patients may have a large disc prolapse with a crossed SLR sign. There is no strong research to support this, but studies have reported clinical usefulness (Fritz et al., 2007).
OTHER DIAGNOSES WE SCREEN FOR ALSO INCLUDE
Sacroiliac joint pain
SIJ symptoms can be diagnosed with 2/4 (thigh thrust, distraction, compression, and sacral thrust) or 3/6 positive tests (includes Gaenslen test on each side). Note that thigh thrust is the most sensitive test and distraction is the most specific, therefore these tests are generally performed first (Laslett, 2005). Patients with SIJ symptoms often complain of unilateral symptoms past the buttock and back pain below L5. They often have a history of trauma or may be postpartum.
Chronic pain / non-specific low back pain
Chronic pain syndrome is commonly associated with psychosocial factors. These factors can have a large impact on ongoing low back pain, and can also influence the diagnostic accuracy of clinical tests (Laslett, 2006). We look for signs of fear avoidance, poor coping skills, and catastrophizing during our assessment. We also use outcome measures to help us screen for yellow flags, such as the ACC acute low back pain questionnaire, the fear avoidance beliefs questionnaire and other relevant screening tools. Addressing these factors at an early stage helps to prevent any unnecessary time off work and will reduce the risk of symptoms becoming chronic.