Waddell Sign

Anatomy and Physiology

Waddell signs were developed solely for evaluation of patients with low back pain.

Indications

No formal consensus recommendations are available on when to assess for Waddell signs. However, it should be included as part of a thorough physical examination of a patient presenting with lumbar back pain. The provider must exercise careful interpretation of their findings as behavioral responses provide useful clinical information. As Main and Waddell propose, positive Waddell signs in a patient only offer a psychological alert that may warrant a complete psychological evaluation.[2]

Contraindications

No contraindications are formally present for performing physical examination techniques that test for Waddell signs. However, caution is warranted when performing specific provocative maneuvers. These include the axial loading, acetabular rotation, and distracted straight leg tests. For instance, axial loading should be avoided in patients with a severe neck or cervical spine injury. Avoidance of acetabular rotation is also recommended if there is a pathology in the hip joint, such as labral tears.[3]

Equipment

No special medical equipment is necessary. Ideally, the patient should either be seated upright in a chair or lie supine in bed while testing for Wadell signs.

Personnel

A physician with training in physical medicine and rehabilitation or pain medicine is preferable.

Technique or Treatment

Waddell signs include: [1],[4]

• Superficial tenderness: The patient’s skin over a wide area of the lumbar skin is tender to light touch or pinch.
• 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.
• Axial loading: Downward pressure on the top of the patient’s head elicits lumbar pain.
• Acetabular 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.
• 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.
• Regional sensory disturbance: The patient experiences decreased sensation fitting a stocking-like distribution rather than a dermatomal pattern.
• Regional weakness: Weakness, cogwheeling, or the giving way of many muscle groups that are not explained on a neuroanatomical basis.
• Overreaction: A disproportionate and exaggerated painful response to a stimulus that is not reproduced when the same provocation is given later. These responses can include verbalization, facial expression, muscle tension, or tremor.

Clinical Significance

The eight tests are commonly grouped into five broader categories. These categories include superficial and non-anatomic tenderness, axial loading and acetabular rotation simulation, distraction, regional sensory disturbance and weakness, and overreaction. The presence of three or more of the five signs has been the most consistently used criterion for a positive test; this suggests that symptom magnification or possible illness behavior may be a significant factor for the patient’s manifestation of pain.[1],[5],[6] However, a validity study suggested that to optimize the homogeneity and variability of the Waddell score, the provider should sum up individual signs instead of categories.[7]

A systematic review was performed by Fishbain and colleagues in 2003 to evaluate the evidence on various interpretations for the presence of Waddell signs on physical examination.[8] This review concluded that Waddell signs do not correlate with psychological distress, do not discriminate organic from non-organic problems, and the underlying pathology may represent an organic issue. Further, Waddell signs were associated with poorer treatment outcomes, higher pain levels, and not related to secondary gain. Fishbain and colleagues performed another systematic review in 2004 which failed to demonstrate an association between Waddell signs and secondary gain or malingering.[9]

An article by Ranney et al. raises the recurrent issue that Waddell signs have been inappropriately used by clinicians to “prove” the absence of physical pathology, regardless of the location of pain, and even to suggest that patients are faking their pain.[10] This article proposes that advances in neuroanatomy may help explain Waddell signs using known physiologic mechanisms and the possibility that some signs may be the result of maladaptive physical responses. For instance, superficial tenderness may be explained by allodynia which is a result of central nervous system sensitization. Additionally, the wind-up phenomenon may be a consequence of neuronal injury that subsequently leads to prolonged nociceptor input via c-fibers; this, in turn, leads to an exaggerated response to afferent input and an increase in the size of the skin’s receptive field.[11] Neuronal plasticity in the pain reception areas of the spinal cord’s dorsal horn may explain non-anatomical tenderness. Based on the work of Hoheisel and colleagues, a painful stimulus can cause marked changes in the connectivity of the dorsal horn, causing new receptive pain fields to form in the spinal cord; thus, formerly ineffective synaptic connections with the periphery form and are potentiated, leading to referred pain and pain that crosses known anatomic boundaries.[12] Finally, overreaction may be based on pre-accident personality or central sensitization syndrome. To this end, Ranney and colleagues proposed that the term “non-organic” should not be used in clinical practice, but instead be replaced by “behavioral responses to a physical examination,” a term first coined by Chris Spanswick in 1997.

Enhancing Healthcare Team Outcomes

Waddell signs may be used by the orthopedic surgeon, rheumatologist, physiatrist, neurologist or spine surgeon, and specialty trained nurse practitioners and physician assistants to assess a patient with low back pain. Unfortunately, there is no randomized study that has determined its sensitivity or specificity for low back pain. Although Waddell signs have been a useful screening tool in the low back pain population, other studies have adapted these signs for evaluating other pain locations. One example is Sobel and colleagues who developed and standardized a group of cervical signs to identify patients with low neck pain who exhibit abnormal illness behavior.[13] 

Patients with low back pain will often recover with limited therapy. However, if the pain persists, or neurologic signs develop, an interprofessional team approach is necessary. Nurses should assist in monitoring patients for improvement and providing patient education. If the patient's symptoms and signs become worse, the nurse needs to identify the concerning findings and report to the clinician managing the patient as soon as possible. For patients prescribed pain medications, the pharmacist should educate the patient on appropriate dosing and compliance. If there is a failure in improvement or the patient describes worsening symptoms, the prescriber should be contacted as soon a possible.

If the patient continues to have low back pain, then perhaps one may need to perform an imaging study. In any event, the best approach to provide the best outcomes is an interprofessional team effort to evaluate, treat, and monitor the patient. [Level V]