Core stability
Back in the late 1990s, “Core Stability” started getting popular. Studies found that people with back injuries and chronic lower back pain had wonky timing in their trunk muscles, basically, their muscle coordination was off. This got researchers thinking -maybe strengthening certain muscles, like the transversus abdominis (TrA), could help fix this and prevent pain and injury. They came up with all these exercises: the "tummy tuck", “trunk bracing” and the “core stability” craze grew.
Core muscles?
The passive human spine is an unstable structure and needs further stabilization which is provided by co-contraction of trunk muscles. These are often called “core muscles” but this isn’t a helpful name, because it suggests there is a distinct group of muscles with a special function that provides stability.
Our bodies are wired in a complex way where our brain calls the shots, we can’t flick a switch and activate one muscle at a time. It's more of a team effort, with different muscles pitching in depending on what we're doing.
When there is talk of “the core” there is the suggestion that transverse abdominis (TrA) is meant to be the main muscle at the front of the trunk that does the job of stabilization. But this isn’t quite right. The TrA is a deep muscle that does help with stability together with other muscles, it acts in controlling pressure in the abdominal cavity for speaking, breathing, pushing when defecating and vomiting.
Practice the moves you need
When you play the piano – the more you practice, the better you get. This is called the similarity principle. Basically, you can't expect to become a piano virtuoso by strumming a banjo. But it's not just about getting better at stuff – it also changes how you look. Think about a weightlifter compared to a marathon runner. They've got different bodies because they've trained for different things. That's the specificity principle at work.
So, if you're training to tighten up your TrA while lying on your back, it doesn't automatically mean you'll be a pro at it when you're standing, running, or doing anything else. You’ve got to practice those moves too. There was a study where they checked if training on a Swiss ball could beef up core stability muscles and improve running efficiency. It didn't. It's like trying to get better at playing the piano by strumming a banjo – totally different skills.
There's no one-size-fits-all exercise for trunk control that works for every activity. If you want to get better at something specific- just practice that activity, and your trunk muscles will get a workout.
Core Strength Exercises for back pain?
People often assume that you need super strong core muscles to keep your spine stable. Yet, there's a study that found the activity in your abs can look similar whether you've got back pain or not. Research on people with weak abs but no back pain found that adding core exercises to their routine didn't make any difference in preventing future back issues. Even collegiate athletes hitting the core circuit didn't see a significant drop in their back pain levels.
And even when we try to strengthen those “core muscles” with exercises such as plank, it might not do much to ease the pain. These exercises often fall short of hitting the force levels needed to really change those muscles. You'd need to crank up the intensity way higher to actually see some gains in strength.
When you're just standing or taking a stroll, your trunk muscles don't really kick into high gear: they're at minimal activation levels. So, it makes you wonder, do we really need to hit the gym and pump iron to keep our backs happy? Maybe not, because these low activation levels suggest that losing a bit of muscle strength might not be a big deal for keeping your spine stable.
Proof this isn’t nonsense? Core and pregnancy
During pregnancy, the belly muscles stretch out like crazy, which messes with their strength and ability to keep the pelvis stable. In a study of 318 pregnant women, some couldn't do a single sit-up because of this stretching. Surprisingly, though, there wasn't a clear link between weak belly muscles and back pain during pregnancy. So why are pregnant folks still told to strengthen their core for back pain if there's not much evidence it helps?
After giving birth, it takes about 4-6 weeks for the belly muscles to bounce back and get shorter again. Plus, it takes about 8 weeks for the pelvis to stabilize. So, during this time, the spine isn't getting much support from those loose belly muscles. According to the ‘weak core equals back pain theory’, everyone during this post-birth period should be in mega pain. But in a study of 869 pregnant women, over half of them had their back pain dramatically reduced within a week after delivery, even though their belly muscles were still all over the place. How does that work? Why doesn't the spine just collapse?
Core and obesity
What about obesity? You'd think that having a big belly would mess with how your trunk muscles work, including the transversus abdominis (TrA). According to the core stability idea, this should mean more back pain. But studies show that being overweight or obese only slightly increases your chances of getting lower back pain. (Just to be clear, being obese isn't a great idea, but it might not necessarily give you backache.)
And even if you have surgery that sliced into one side of your belly muscles such as rectus abdominus, (like during breast reconstruction after a mastectomy), you'd think it'd mess with your movement and cause back pain. But surprisingly, it doesn't.
Engage your core, but it squishes your lower back
Recent studies have been looking into manoeuvres like abdominal hollowing and bracing, which are often part of Core Stability training. While they do help stabilize the spine, they also increase the pressure on the spine, and for those with lower backache it adds pressure to the already sensitive spinal joints and discs possibly making their pain worse. Plus, all that tension in the trunk muscles can put a real strain on the ligaments in your pelvis, especially if you're already dealing with pelvic pain.
Focusing too much on squeezing specific muscles during your workouts could actually backfire: thinking about all those tiny muscle movements can mess you up. It's like trying to play hockey while obsessing over every little movement in your fingers. It’ll slow you down.
Our bodies are all about efficiency – we want to use just the right amount of energy to get the job done. But if you're constantly tensing up like you're trying to hold in a sneeze, you're wasting precious energy that could be better spent on focusing what you are doing.
What to do instead?
If you have lower back pain the suggestion is to loosen up those trunk muscles instead of holding them tight all the time. Consider that psychological stress can really mess with your spine health too. Things like catastrophizing and somatization, can get even worse if you're constantly hyper-focused on back pain. Shifting the focus away from the back and start tackling the whole picture – you know, the physical stuff and the mental stuff too.
Conclusion
Although the concept of a 'strong core' has been widely emphasized, research suggests that the importance of trunk muscle strength may vary among individuals. Contrary to common beliefs, having weaker trunk muscles, including the abdominals, may not necessarily predispose individuals to back pain or other issues.
Instead of fixating solely on muscle strength, a holistic approach to spine health that considers factors such as posture, movement patterns, and mental well-being may be more beneficial.
This blog is based on this paper by Prof Lederman.