Range of Motion

Physical therapy and how it straddles the line between science and craft.

Monday’s post highlighted how physical therapy sits at the heart of the tension between populations and individuals in modern scientific medicine. The field addresses one of the core problems people come to their doctors with: musculoskeletal pain or restriction. More often than not, these ailments can’t be treated by simple prescriptions of rest, drugs, or surgery, and primary care physicians don’t have solutions for these problems. So instead, they are often referred to physical therapy, which combines an uncomfortable mix of science and craft that eludes clean, evidence-based evaluation.

I’m a bit of a PT fanatic, and have had the privilege of working with five excellent physical therapists since I got a bit too overly serious about strength and conditioning in my forties. They were all very different, but all of them applied the same core principles. These principles highlight key aspects of what it means for a therapy to be individualized.

Every PT consultation begins with an assessment. Because there are so many moving parts and everything is so interconnected, it’s often hard to identify a single cause of a particular pain or restriction. Weakness in one area is balanced by strength in another. Pain in your foot might be caused by limited mobility in your hip. While everyone’s musculoskeletal system is connected in the same way, we have wide variability in the sizes, shapes, and positioning of our muscles and bones. Once we combine this with the variability of people’s physical interactions with reality, we find there’s no single simple answer for everyone. Each person is a weird biomechanical puzzle, and not every puzzle is particularly easy to solve. However, there is a set of therapeutic principles for making people better.

A therapist will test out the range of the different muscles and joints that could be connected to your symptoms. They try to find how far you can move without pain, which is a mix of qualitative (pain) and quantitative (degrees of rotation). Once they find which specific movements are restricted, they have a general process to fix all of them.

First, the therapist will open the restricted range using some sort of manual therapy. This is done in a single session and might involve stretching, deep-tissue massage, or even cupping (more on that later). Next, they give you exercises to gain control over that newly opened range. This is done between sessions with the homework exercises they assign you. After you can confidently access this new range, you load it, adding strength-bearing exercises to further strengthen the mobility you aim to increase. All of these are progressed over time, adding more intense manual therapy, more difficult exercises, and more weight.

Progression is the core principle, whether you’re treating tennis elbow or a sprained hip (I’ve had both). The difficulty of your physical therapy exercises will gradually increase with each session. It’s sort of obvious when you say it that way, no? This is all there is to the buzzy principle of progressive overload. It works because your body adapts to stress. When you add enough stress, it overcompensates and resists the stress more strongly the next time. Cascading this reaction over a long period in a controlled, thoughtful way leads to a clear and measurable outcome.

The complication is that bodies adapt more slowly than most of us would like. It might take weeks to start to see progress. Because progressive overload is slow, lots of people walk away from physical therapy convinced that their injury would have just gotten better anyway. They might be right, and I can’t argue their concerns away. But that’s why I’ve found it helpful to track progress over time. It might not be the PT prescription that lets me access that extra range or strength, but I feel more in touch with whatever it is that my body is doing. I’ve found that it’s worth targeting something even more ambitious than just “back to normal.” I now aim to come out of physical therapy more capable than I was before my symptoms started.

For many people, PT doesn’t work. I like it, but I might be particularly well suited for it. I love rituals. I love obsessing about niche minutiae. I love tracking and journaling. But recovering from injury and managing pain are not easy. Compliance with physical therapy might be a greater challenge than with other treatments. It’s a much bigger commitment than “take two pills a day with meals.” If you don’t like to spend 30 minutes a day on weird stretches, PT might not work for you. But that doesn’t mean it doesn’t work for someone else.

And this is why physical therapy is so easy to attack on scientific grounds. How do you run a controlled trial on a practice this complex and individualized aimed to treat subjective symptoms like pain? I’ll dig into the impossibility in the next post.