Low Back Pain in the Workplace

Importance of Precise Communication

William B. Dasher III, M.D.

Low back pain is a very common problem in the population as a whole and especially in the workplace. Evaluating the patient with low back pain can be difficult, especially in the setting of a workers’ compensation injury.

Initial evaluation should include a detailed history of the injury, a comprehensive physical examination, and review of radiographic studies (if indicated or provided). Most importantly, one must rule out serious pathology, including fractures and/or spinal cord or nerve root dysfunction. In addition to these injury-related problems, consideration must also be given to the possibility of tumor or infection. Usually a good history and physical exam will allow the physician to quickly determine the severity of the problem.

When performing a physical exam on a patient with low back pain from a work-related injury, the use of Waddell “non-organic” signs can potentially help determine the likelihood of response to treatment. They must be used with caution; however, as several authors have suggested that these findings may not be as helpful as once thought.

Waddell signs:

1. Superficial tenderness: the patient’s skin over a wide area of the lumbar spine is tender to light touch or pinch 2. Non-anatomical tenderness: the patient experiences deep tenderness over a wide area that is not localized to one structure and crosses over non-anatomical boundaries 3. Axial loading: downward pressure on the top of the patient’s head elicits lumbar pain 4. Torso rotation: lumbar pain is elicited while the provider passively and simultaneously externally rotates the patient’s shoulder and pelvis together in the same plane as the patient stands. It is considered a positive test if pain occurs within the first 30 degrees of rotation 5. Distracted straight leg raise discrepancy: the patient complains of pain during a straight leg raise during formal testing, such as when supine, but does not on distraction when the examiner extends the knee with the patient in a seated position 6. Regional sensory disturbance: the patient experiences decreased sensation fitting a stocking-like distribution rather than a dermatomal pattern. 7. Regional weakness: weakness, cogwheeling, or giving way of many muscle groups that are not explained on a neuroanatomical basis 8. Overreaction: a disproportionate and exaggerated painful response to a stimulus that is not produced when the same provocation is given later. These responses can include verbalization, facial expression, muscle tension, or tremor

The number of Waddell signs that are positive should be noted, as three or more has been shown to be more predictive. Once the H&P are completed, imaging studies are often ordered/reviewed. X-rays, CT, and MRI are often utilized depending on the injury, physical exam findings, and/or response to treatment. MRI must be interpreted with caution; however, because there is a high incidence of pathology found in asymptomatic patients. Numerous studies have shown that findings of disc bulges, disc protrusions, facet arthritis, and stenosis are often seen in patients with no history of back pain. However, disc extrusions are not typically seen in asymptomatic patients. The patient’s complaints, exam findings, and imaging studies must be interpreted together in order to be useful.

The large majority of patients presenting with low back pain can be treated non operatively with time, physical therapy, chiropractics, heat/ice, NSAIDs, etc. Multiple studies have shown that a brief period of rest (1-2 days), followed by a quick return to normal activities will result in the best outcomes. More invasive treatments including epidural steroid injections and facet injections can be considered for patients who have not responded to lesser treatments. Ultimately, in very select cases where the pathology is clear and the patient is reasonable, surgery can be considered. The outcomes of surgery in the workers’ compensation population have clearly been shown to be inferior to the outcomes in non-WC patients; however, it can be a very useful tool in the right patient with the appropriate pathology. Surgery usually involves decompressing neural structures (laminectomy, foraminotomy, discectomy), with the possibility of fusion and/or disc replacement. These can be done through a myriad of techniques, both open and minimally invasive.

While low back pain can be a challenge to treat in this population, it is one of the most significant causes of lost work time and expense. It should be evaluated and treated expeditiously and judiciously.