Every interview season, I ask residency applicants why they want to match into our physical medicine and rehabilitation (PM&R aka physiatry) program. They often respond with personal stories of family members who benefited from aggressive rehabilitation interventions, a lifelong interest in sports and exercise, or a healthy work-life balance. Recently, however, I have had more medical students say that they are applying to our field so that they can practice functional medicine.
The reasoning is easy enough to follow. They have likely learned that PM&R is the specialty concerned with function, and have also encountered the field of functional medicine during their training. The names align nicely, so it is natural to assume that the domain content aligns as well. If cardiology training is the correct pathway to become a cardiologist, it would make sense that training in the medical specialty that deals with function would be the correct pathway to practice functional medicine.
Due to its relatively small size and unique clinical scope, the specialty of PM&R has often suffered from general misunderstanding about its nature and role in medicine. We don’t necessarily own any specific organ system or disease process. Name recognition has likely suffered as “physiatry” sounds similar to “psychiatry.” The term “physical medicine and rehabilitation” is often conflated with the work physical therapists and other rehabilitation clinicians perform. Given these branding challenges, physiatrists will often refer to themselves as “physicians of function.” This phrase has been a simple yet effective way to help capture and describe our specialty’s organizing purpose. With the increasing popularity of functional medicine, however, the term “physician of function” has the potential to be conflated with another field of medicine again despite limited overlap of domain content.
In physiatry, function refers to what a person can do. It is an outcome, and usually a measurable one. Can a person stand and walk independently? Can they dress and feed themselves or with help from a caregiver? Are they able to perform their job functions appropriately? This framework is not proprietary to the specialty, and it maps onto the World Health Organization International Classification of Functioning, Disability, and Health (WHO ICF), which places function at the intersection of a person’s body, their activity, and their participation in the world. When a physiatrist like myself talks about improving function, I am referencing someone’s ability to live life to their fullest capacity.
Functional medicine uses the term function somewhat differently. Here, function describes a proposed state of the body’s underlying systems. Functional medicine is a patient-centered framework that proposes that disease arises from dysfunction at the level of a person’s physiology, metabolism, and the environment, and that treatments should target root causes at this level, instead of focusing on a presenting symptom or diagnosis. Function, in this usage, is not the outcome being measured, but the mechanism being theorized.
It's a clean distinction once we make it. One field uses function to name what it is trying to restore. The other uses it to name what it believes has gone wrong. One is a destination, the other, an explanation.
It could be easy to treat this as a harmless semantic issue. But for many physiatrists, it isn’t. Physiatry has spent decades as one of medicine’s more misunderstood specialties, and the term “physician of function” was, in part, an attempt to fix that. If this phrase now drifts toward a different field, physiatry loses a piece of language that had begun to effectively explain it.
The cost is not only reputational. Referral patterns follow understanding. When a physician cannot distinguish what a physiatrist offers, patients who would benefit from rehabilitation care (the stroke survivor with spasticity, the patient with limb loss needing a prosthetic device, or the athlete searching for orthobiologic interventions for their pain) are not referred, or are referred late. The confusion is now also evident upstream in the applicants who mistake one field for the other. A specialty that cannot name itself clearly is a specialty whose patients are harder to reach. The word “function” is not decoration here, but is our specialty’s clearest signal to the rest of medicine about who we serve.
In these interviews, I don’t correct the applicants sharply. They aren’t confused about the two fields themselves, just the assumption of what is the best pathway to reach their eventual goal of practicing functional medicine. So I explain in more detail what physiatry training entails and where it does and does not overlap with what they are picturing. Better to appreciate the distinction now than several years into residency training. Either way, the conversation is worth having. Not to defend our specialty’s use of the phrase itself, but to ensure that the students who are drawn to our field appreciate the long tradition we have of caring for patients who want to improve their function.
