For today's post, I want to pose more of a question. One of the foundations of physical therapy training, as it typically takes place during the first year, is range of motion (ROM) measurement. ROM measurement involves using a goniometer (or landmarks) to assess the mobility of a joint. If you take a look at people around you, you'll likely see a significant variety in mobility at each joint for each person. But where do the ROM norms come from?
As you look at different texts, you will find it difficult to find two different texts that have the same ROM degrees or landmarks in each of them. This doesn't necessarily answer the question about where ROM norms come from. They typically are averaged over a certain population. The issue with that is that here is significant variety in each population and the standard motions found may not necessarily accurately represent the true motion available. For example, consider the patient with only 10 degrees of lumbar motion (no pain) however following a set of repeated lumbar extensions, quadruples the mobility. There are many people that when measured "cold" will not demonstrate the normal mobility and they are asymptomatic. What are the odds that many of these people were used in a research study?
I cannot say I have a certain answer, or that it is even worth seriously considering, but there are several possibilities or options. One is to base our standards off a younger population. Typically infants and young children are less likey to have developed compensations and restrictions, so maybe base our norms off them? A system like the Selective Functional Movement Assessment (SFMA) partially bases its standardized norms off these, but the most important part is to be consistent in your assessments. You will find norms from your experience, but also within each individual. I'm sure from your experience you have found that some patients are "hypermobile" and some are "stiff" throughout and exhibit a significant loss of motion everywhere. You want to take your measurements throughout the body and definitely compare side to side and with people in a similar population. While this method is not perfect, the most important factor is that you are consistent. What are your thoughts on this issue?
-Dr. Chris Fox, PT, DPT, OCS