It's Time to Throw Away the Schober Test for AS
The journey to a diagnosis of ankylosing spondylitis (AS) is riddled with challenges that prevent patients from receiving the diagnoses and treatment they need. In particular, misconceptions about AS can lead doctors to conclude that a patient does not have AS, when they do. For example, I was told by a doctor that I most likely did not have AS because it usually occurs in men — this is not true. It is also commonly believed that patients with AS are immobile and have a bamboo spine — this is also not always true.
To test for this decreased spine mobility, many doctors use the Schober Test, in which they draw two lines on the patient’s spine, 10 cm apart. Then, the patient leans forward and the doctor measures how much the distance increases between the two lines. An increase below 5 cm is positive and indicates AS, while an increase of 5 cm and above is negative and does not indicate AS.
Here is the problem with the Schober test
The Schober Test measures the loss of mobility that can be caused by the progression of ankylosing spondylitis over many years. It does not test for ankylosing spondylitis in the first place. Sure, the Schober Test is accurate for someone with years of untreated AS and the resulting vertebral fusion. However, for anyone who is newly experiencing symptoms of AS, it is highly unlikely that they would have a positive Schober Test. This results in many patients with very real AS being misdiagnosed or receiving no diagnosis at all.
When I was 18 years old and reporting symptoms of AS — particularly, sharp pain in my SI joints — several doctors performed the Schober Test on me. But because I am young and a figure skater, I was highly mobile. In fact, I could still bend into the figure skating layback position! My Schober Tests were obviously negative — yet I still had many other symptoms of AS and its genetic marker. Eventually, I was properly diagnosed with AS.
You can have AS and a mobile spine
My rheumatologist, who luckily is up to date on AS research, explained to me that the Schober Test is inaccurate — you can have AS without having severe immobility and a stiff spine. If more medical professionals were aware of this, many people with AS could be diagnosed earlier, preventing them from ever progressing to spinal fusion.
It is unfortunate that many medical professionals are unaware of current research on AS and the various ways it can manifest, and that they continue to perpetuate these misconceptions. Education on AS and other similar illnesses needs to be updated to reflect accurate disease characteristics and the various ways in which AS can present. Throwing away misconceptions and the Schober Test will prevent people from experiencing unnecessary prolonged pain.
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