Is pain during rehab exercise “OK”?

*Medical Disclaimer: Please be advised, the information provided in this article is educational in nature and not meant to diagnose or treat any disease, illness, or condition. For individualized recommendations it is best to follow up with a licensed provider, like myself or another physical therapist.

A common concern among clinicians is when a patient experiences pain during exercise. Some clinicians rush to modify the exercise so that the patient has no pain whatsoever. Others ask the patient to describe the pain, trying to differentiate between muscle fatigue and nociceptive pain. And some say it’s just part of the rehab process.

Thankfully in the past couple of decades research has been building on this question. In 2017 Smith et al. did a systematic review trying to answer this question. Their review included studies that:

-Were randomized control trials that compared exercise where pain was allowed/tolerated vs exercise that was pain-free
-Had adults with chronic musculoskeletal pain (defined as >3 months)
-Measured pain, disability, or function

*Note that adults with “non-musculoskeletal pain” were excluded (this list ranged from cancer to headaches to fibromyalgia).

From their search, 7 studies made the cut: 1 trial on low back pain, 3 trials on shoulder pain, and 3 trials on foot/ankle pain. Patients in the studies were instructed that pain during exercise was acceptable (in some studies up to even 5/10 on the VAS), but that the pain should subside afterwards.

They then analyzed the effectiveness in the short (<3 months), medium (3-6 months), and long term (>12 months).

The results?

– Short term, patients who had pain during exercise had statistically significantly LOWER pain scores compared to pain-free exercise
-Reductions in pain levels were similar in the medium and long term between groups
-Improvements in disability and function were similar in the short, medium, and long term between groups

In short, for patients with chronic pain, pain-free exercises and exercises where pain was allowed resulted in similar outcomes (though short term, exercises where pain was allowed led to significantly decreased pain levels). However, we still don’t know about acute injury and post-surgical patients. We likely have to rely on clinical judgement for this. Also, the research doesn’t address other regions of the body (knee, elbow, neck, etc), but I think that we can reasonably generalize the results to other regions of the body-it is likely that chronic pain responds similarly to treatment, regardless of the region of the body. Lastly, a major limitation is that patients with conditions like fibromyalgia and migraine were excluded-this is a major group of patients who suffer from chronic pain! It would be helpful to examine the effects of painful exercise in these populations.

A few questions remain for me:
-Is there a ceiling on the “allowable pain” during exercise? Is there a point of “too much” pain?
-Related, is pain post-exercise “OK”? Would patients have better or worse outcomes if the pain from exercise lingered for a couple days?
-After discharge from therapy if a patient experiences pain with general exercise (a general training program), does this predict future pain?

Here is the original paper for review: https://bjsm.bmj.com/content/51/23/1679