Hello -
Firstly, Im a big fan of both BBmed and the SPOSR team, so thanks for all your work.
Since both entities are deeply involved in pain science and Dr. Baraki posted such a good article on OA I thought I would post these questions here:
Most importantly, how much pain is OK when rehabing a joint affected by OA? Mechanistically and clinically there is research to show that relatively high pain levels are acceptable with tendonopathy. Is there corresponding literature for OA? Is there any research to suggest that consistently performing aggravating activities will accelerate OA? This is an especially important question because patients invariably ask, “If I keep doing X and it is painful will it accelerate degeneration?”. A very valid question.
Finally, a recent cochraine review (Hurley 2018) on the effects of exercise on OA found an average of 5-15% improvements in pain, function, QOL, etc. When educating patients should we tell them that exercise will likely improve their symptoms by <20% (generously speaking, based off the referenced article)? Specifying such a small effect size may reduce patient expectations and thus the effectiveness of the treatment, on the other hand they deserve to know “the truth” so they can allocate their resources according to their values and according to the true effect size of any treatment.
Your thoughts and time are greatly appreciated.
Nathan,
The answer to how much pain is acceptable would be the ever ambiguous “it depends.” The article that is typically cited in reference to this is Smith 2017https://bjsm.bmj.com/content/bjsports/early/2017/06/07/bjsports-2016-097383.full.pdf This goes against the normal dogma taught in PT school (Mike can speak to chiro) of constantly assessing pain and attempting to avoid pain during rehab. I have never seen a paper suggesting that consistently performing aggravating activities accelerating OA. There is the paper by Alentorn-Geli (The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis - PubMed) looking at running and knee and hip OA giving a Bayesian result. Sedentary lifestyle correlates with OA and high volume OA correlates with OA. The problem being assigning values to what constitutes high volume unique to the individual. To you example, unless “X” is being sedentary, the answer is “highly unlikely.”
The paper I typically reference for for the effects of strength training for OA is Bartholdy 2017 (The role of muscle strengthening in exercise therapy for knee osteoarthritis: A systematic review and meta-regression analysis of randomized trials - PubMed) where it turns gainzzzz into a quantifiable number to decrease pain and increase function. Their regression shows a 30% increase in strength in necessary for a decrease in pain and a 40% for a decrease in function. Now, framed in real world terms it likely would not be uncommon for certain individuals to only be able to generate 20-30# of force with their quadriceps so taking them to 30-40# would likely be sufficient for improvement.
As to the effect size, I’m going to play the “heterogeneity of what constitutes exercise” card. There is a huge difference between 3x10 straight leg raises, nonprogressive loading of 3x10 without a measurement of intensity, and the protocol used in the LIFTMOR trial (High-Intensity Resistance and Impact Training Improves Bone Mineral Density and Physical Function in Postmenopausal Women With Osteopenia and Osteoporosis: The LIFTMOR Randomized Controlled Trial - PubMed). We also have the paper by Churchward-Venne to bolster the support of duration of training as well (There Are No Nonresponders to Resistance-Type Exercise Training in Older Men and Women - PubMed). If we only advocate for training to be a finite process of 4-12 weeks, we are likely missing the boat on the overall benefits of training for individuals. As for directly related to OA, I would broad frame out and reference the Dankel paper showing individuals who resistance trained 2x/week had a reduced risk of all cause mortality by 23% (Dose-dependent association between muscle-strengthening activities and all-cause mortality: Prospective cohort study among a national sample of adults in the USA - PubMed) and Kraschewski 2016 looking at mortality prospectively (Is strength training associated with mortality benefits? A 15year cohort study of US older adults - PubMed).
I tend not to ballpark the percentage of improvement I expect when speaking to patients because it ultimately is up to the patient and I am a facilitator. If I tell them to expect 20% I could be short changing them larger gains and if their current function is being able to walk 300ft without pain then getting them to able to ambulate 360ft would still be short changing a functional outcome in my opinion. Instead, I try and make it a conversation of a series of small wins; last week you got to the mailbox, this week you got to the mailbox and back. Your knee hurt after you went and walk around Disney all day with your grandkids, a month ago you wouldn’t have even considered going to Disney in the first place. Telling anyone that doing an activity is going to increase their prevalence of OA is painting that person in to a corner of avoidance behaviors. Too many patients have stopped lifting, running, living based off poor advice by medical providers that demonize perfectly normal things. If I get OA from lifting weights as much as I do…cool, I’m doing what I love. There is a low correlation between having OA and experiencing pain and being strong reduces the risk of symptoms, I’ll take those internal wrinkles in my knee joints. Maybe instead of “nobody puts baby in a corner” we should be quoting “nobody puts granny in a wheelchair.” Cue “I’ve had the time of my life” dancing montage…
Hey Derek - thank you so much for the reply. Some good references there and overall its very interesting to know how you think.