Chiropractic technique hangs by a thread. After some 118 years of this, we have not convincingly demonstrated that the information provided by our examination methods has much to do with the outcome of care. I am not referring to serious cases with clear findings, like orthopedic tests suggesting herniated disc, but rather the other 95 percent or more of patients who come in with fairly straightforward musculoskeletal pain complaints. We do what we can to diagnose (we used to say "analyze") these patients, which amounts to coming up with listings.
To put it simply, listings are indications for care. Whatever the historical derivation of the term "listing," which seems to suggest a leaning or misaligned spine, we now ascribe several characteristics to the term. There are dynamic listings, having to do with impaired joint motions; static listings, which involve bones that have lost normal juxtaposition; and most recently provocation listings, (1) which in essence are evoked responses to "challenges" that we put into the neuromusculoskeletal system. As examples of the latter, we observe if relative leg length appears to change when the head is turned, or if presenting lumbar pain at L5 is made worse or better with pressure on the left transverse process of L4.
Most listing systems have not worked out very well for chiropractors nor for those in the other manual therapy professions. Static listings tend to lack validity, in the sense that there is poor correspondence between radiographic subluxations and patient complaints. Patients with radiographic lesions do not tend to have corresponding pain, and patients with pain do not tend to have corresponding radiographic lesions. There is little evidence that patient improvement has much to do with radiographic improvement. Dynamic listings have fared no better. They tend to lack reliability. There are dozens of studies, many done rather well, showing little interexaminer agreement above chance levels. (2) I point this out despite having published two studies wherein cervical and thoracic motion palpation were found to be reliable under some fairly delimited circumstances. (4,5) As for provocation listings, (3) which more or less mark a return to classical orthopedics, the jury is still out on how clinically valuable they will be. Personally, I am encouraged, and have myself published a little on provocative blocking, (6-8) which was inspired by work done by McKenzie researchers on the degree to which defined vectors mattered in the exercises they prescribe.
And so we have a standoff here: invalid static findings vs. unreliable dynamic findings. There are no winners in this situation, except perhaps those who consider us anti-scientific cultists. As a technique instructor, I take a class through a certain dilemma once every three months as a training exercise in critical thinking. I demonstrate for them surrogate muscle testing, (9) which has been used in situations where the patient cannot be directly muscle tested by an examiner. For example, a 2-year-old child, who doesn't understand the concept of resisting during a muscle strength test, is tested by having a parent...