Abnormal Is The New Normal

The world of musculoskeletal care is a strange animal if ever there was one. It is a world of imbalances and mal-alignments, asymmetry and inflexibility. Or so we are taught, and have been for decades.

The world of musculoskeletal care is is also the same realm that would benefit most from an understanding of clinical anatomy, statistics, and logic.

Diagnosticians are always seeking some relationship between a patient's signs, symptoms, and some particular patho-anatomical entity. But the problem lies in the realm of normalcy. You see, abnormal is, without question, the new normal.

Normalcy presents a number of problems to diagnosticians. Let's just start with the statistics of biomechanical alignment and symmetry. Reid noted in 1992 (yes, 1992) that “mal-alignment is a term that should be reserved for gross abnormalities, two SDs (standard deviations) outside the norm”. For those who like math, that would mean that, statistically speaking, 95% fall within the bounds of "normal". That is a whole lot of normal.

Expand on this thought a bit. Spend some time in cadaveric dissection and you quickly see a steady stream of anatomical variations. They are the norm, the rule instead of the exception, the vast majority of what we see and experience. Take the piriformis muscle as but one small example, both anatomically and statistically. Research would indicate that up to 40% of people have abnormalities, yet may or may not have symptoms associated with it.

Examine some of the research done via MRI on asymptomatic individuals and you will find some disturbing - or comforting - results. A variety of peer-reviewed studies have shown that positive, abnormal MRI (of the lumbar spine, shoulder, knee, and hip) exists regularly in asymptomatic patients. More on that in a future post.

Wow. Pain-free and functional yet "abnormal". No worries though, because it all fits from a statistical perspective. Clinical anatomy tells us that these types of numbers have been well-known for some time.

Part of the problem is in the perception of "abnormal" and "normal" - a rather significant element of the diagnostic process. Edward de Bono notes that 90% of errors in thinking are errors in perception.

But with that said, there is an inherent beauty in all of this. Perhaps the solutions to this diagnostic problem can be found in the problem itself.

Normalcy causes us to question our thinking about musculoskeletal pathology, its relevance, and its context. Abnormal is the new normal. It's now what we do with that knowledge of clinical anatomy that will provide us with the foundation for a new era in musculoskeletal medicine.

Photo credits: Ross Griff

Related Articles By Allan Besselink

• In Pathoanatomy We Trust - But Should We?
• Systems Thinking In Health Care And The Failure Of Patho-Anatomy
• The Inconvenient Truth About Normal