As physical therapists, exercise is a vital part of our practice. We are the movement experts! With that in mind, dosing the intensity of our exercise interventions effectively should be a priority.

Why We Prescribe Isometrics

Isometrics are a widely prescribed type of muscle contraction, with several benefits described in the literature:

• Safely loading tissue, such as in post-operative patients
• Preserving muscle tissue and avoiding atrophy
• A proposed analgesic effect, leading to less pain while still loading tissue

One downside of isometric contractions can be patient specific. Explaining isometric contractions and having patients perform them effectively can be a challenge. I’ve often seen patients use compensatory motions, or push so hard I fear they’ll put a hole in the wall.

What the Research Found

A recent article in Orthopaedic Physical Therapy Practice (OPTP) explored how accurately people can estimate their maximal voluntary isometric contraction percentage (%MVIC). Sixty-seven subjects performed isometric shoulder abduction at different %MVIC levels, and the actual force produced was measured with a handheld dynamometer.

The findings generally showed that subjects undershot or overshot the target %MVIC. Speaking from experience, this is no surprise.

Image spot (optional): isometric shoulder exercise against resistance

What This Looks Like in the Clinic

In my experience, isometric contractions performed by patients tend to be “failed” concentric contractions. In other words, patients try to perform a motion and fail, creating an isometric contraction. This often leads them to overshoot the target %MVIC.

Patients can also undershoot. One example I see often is shoulder external rotation after a rotator cuff repair. Patients often use compensatory motions such as supination or abduction to complete the movement, producing less than the desired %MVIC.

So What Do We Do?

With this information, what should we do as PTs? Stop prescribing isometrics? Change our cues? Use handheld dynamometers to be accurate?

Hamstring injuries are fairly common in our more active patients. The hamstrings are vital for sprinting, much more so than for regular walking. Sports with explosive movements, such as baseball, football and soccer (and of course sprinting!), can lead to hamstring injuries.

There is plenty of research on hamstring strains: the mechanics behind the injury, what to examine and how to treat it. Today we’ll look at a recent article from the September 2026 issue of JOSPT, “Timing and Dose Matter: Late High-Speed Exposure and Higher High-Intensity Acceleration Volumes Reduce Hamstring Reinjury Risk in Elite Male Football (Soccer).”

Return to Play Is Individual

With any injury, there are several factors to consider for return to play, such as level of play, training history and injury history. Talking with the coaching staff is also vital for the best transition back to play. It allows for the right dose of activity to support recovery rather than cause a reinjury.

Image spot (optional): athlete doing a hamstring strengthening exercise

What the Research Found

The article concluded that introducing higher-speed running, sprinting and high-intensity accelerations later in the rehabilitation program was associated with a lower risk of reinjury. A gradual build-up of higher-intensity exercise also led to a lower reinjury rate.

The Takeaway

When considering any patient’s return to sport or previous level of function, we must compare their individual physical demands with their current status. Rushing back to any activity without building adequate strength, and without a gradual progression of exercise tied to their movement goals, often leads to incomplete recovery or reinjury.

I’ll never forget one patient from my first year of practice. She came in with an MRI report in hand, halfway to tears. She didn’t have an appointment. She had come right off the streets of Manhattan, fresh from her visit with her orthopedist, and asked to speak to a PT for some clarity on her imaging results.

A patient had canceled, so reception called me to the front. I gave my standard line, that I was a PT and not a radiologist, but that I would take a look at her report. It said she had multiple severe disc herniations and stenosis throughout her lumbar spine.

Treat the Person, Not the Image

As I read, I noticed something. She was shifting from side to side, pacing and moving with a lot of frantic energy, which is how most of us would react to news we thought was terrible. I stopped reading and asked how she felt right now. She started jumping and squatting to show me how well she was moving. She said she had pain at times but was able to keep up her daily routine.

I reassured her that evidence shows many of us past a certain age will have findings on a lumbar MRI, and that research at the time supported treating the person, not the image. I told her about PT, and she came in for an evaluation with a colleague. By their report, she was a straightforward case! I firmly believe imaging is a powerful tool that helps countless patients, but research shows it shouldn’t fully guide our treatment.

Image spot (optional): patient moving freely during an exercise session

What the Research Found

A recent article in Physical Therapy (PTJ) explored how the severity of structural lumbar spinal stenosis relates to response to exercise-based PT. The study compared improvements in pain, disability, strength, medication use and function after PT-led exercise interventions, with patients grouped by the severity of their stenosis.

The authors concluded that patients improved by the same magnitude across all structural severities of spinal stenosis. I immediately remembered my patient, how terrified she was of her MRI and how mobile and functional she was.

How many patients avoid being active because of the harm they believe their imaging findings mean? How many never see a PT who could improve their mobility or quality of life, because they’ve been told their spine is too far gone?

What We Can Do

We can keep educating our patients, and those around us, on the importance of focused, purposeful exercise to improve their function, and help them avoid putting everything into their imaging results.