This week, we’re talking about isometrics with three different ways to hold still. First, we’re going to see if isometrics actually reduce pain the way we’re taught in school. Then it’s time to see how contract-relax isometrics can help with non-specific neck pain before we finish with how isometric shoulder strength correlates with functional tests for overhead athletes. It’s a lot of ways to hold still and it starts now.
Let’s dive in!
Isometric pain relief? Eh…
The Gist - I know I learned that isometrics are pain relieving in school and you probably did too. But, like, are they really? This systematic review in the journal Physical Therapy in Sport argues that they may not be. It looks like they can be pain-relieving in people who don’t have MSK injuries, but probably not in those who do. That’s from an analysis of 13 different studies with data from 346 participants. They did see that some studies demonstrated exercised-induced hypoalgesia, “but there were no consistent data to show isometric exercises were superior to comparison interventions.”
In their estimation, this was the first review that split out MSK injuries from chronic pain conditions like fibromyalgia. They looked only at studies that used isometric exercise at any location in people with MSK injuries and included any that measured pain during and/or after up to two hours later. The primary outcome was pain threshold while secondary were other pain measures they lay out in the paper.
There was a wide range of study types, exercise interventions, and measurement techniques, making a meta-analysis impossible. But from the data they had, they found that only quad-based isometrics “yielded any effect on pressure pain thresholds or pain in MSK pain cases, however this effect was not consistent.” Studies of the UE did not show any consistent pain relief.
Tell Me More - The point of the pain pressure threshold testing is to see if local pain pathways are modified by an activity. Since we’re looking into hypoalgesia, it should be an effective measure even though I doubt you ever use it in clinic. The point is to look at how sensitive someone is to a painful stimulus. If these exercises are actually making a pain pathway change, they should change how pain is perceived. And, like I said, most of them didn’t.
This study doesn’t tell us anything final, like many studies we see, it’s just full of probablies. Probably, isometrics don’t work to reduce pain when people have pain. Though they may work with the quads, and they may reduce perceived pain, they don’t change the pain pressure threshold, (the overall perception of pain) and may not be the best starter approach for pain relief. That doesn’t mean they’re not good for everything else that isometrics are good for, so obvs don’t throw them out.
A bit more on the suites before I get out of here, the protocols were all very different. One had 21 seconds of time under tension. Another had 600 seconds. And four had the same protocol of 5x45 seconds for a total of 225. So they were all over the place, hence we know nothing for sure, but we have some clues.
Paper? Got it.
The King Crab piece this week, the edition for supporters with 3x the articles and other special features, got a piece that talked about strength performance tests for the shoulder, for athletes. If you’re interested in this, run back to Issue 131, where they’re covered in great detail.
And that’s the week. Enjoy! And enjoy the fall, I certainly am. Bye!