An old injury often hangs around because your nervous system is still protecting it. When your body senses a threat at a joint, it stiffens the area like a natural splint, even after the tissue has healed. The fix is to find where the movement breaks down, strengthen that function, then load it straight back into the full lift.
Most people blame the muscle. “My glute is switched off.” “My shoulder is tight.” But muscles don’t have a light switch, and the tightness you feel is often your body doing exactly what it was designed to do. Understand that, and old niggles stop being a mystery.
I sat down again with Shant, my go-to injury guy at Enterprise Fitness, to break down how the nervous system really drives movement. It’s the layer most trainers, and plenty of clinicians, never talk about.
Can you really switch a muscle on or off?
No. Your muscles can’t do anything on their own. Shant breaks movement into three parts: the passive structures (bones, tendons, ligaments, discs), the active structures (your muscles), and the neural system that tells them what to do. Without the nervous system, the other two are just sitting there waiting for instructions.
Think of a phone with no signal. The hardware is fine. Nothing gets through. That’s why someone with a spinal cord injury can have healthy leg muscles and still not move them: the message can’t reach them.
So when a trainer says your glutes are “switched off”, they don’t mean the muscle is dead. If you can stand up, your glutes work. What they mean, or should mean, is that the muscle isn’t doing enough of its job in a particular movement. Fine as a shorthand. A problem if your trainer actually believes it.
What is your nervous system actually doing?
It has one job: keeping you alive. It doesn’t care about your PB. It doesn’t care about your feelings. It definitely doesn’t care about your Instagram comments. It organises every movement to get the task done with the least threat.
To do that, it turns some muscles up and others down. When you curl a dumbbell, your nervous system dials up the drive to your biceps and dials down your triceps so the curl runs smoothly. The triceps aren’t switched off. They’re turned down. Charles Sherrington described this more than a century ago and won a Nobel Prize for his work on the nervous system.
It’s not a light switch. It’s a dimmer. And for a heavy squat, you want plenty of dimmers turned up at once around your spine, so your trunk becomes a stable platform for your hips to push from. You can’t fire a cannon out of a canoe.
Why does an old injury stay tight?
Because your body is splinting it. When your nervous system detects a threat at a joint, it over-drives certain muscles to stiffen that area and limit movement. It’s a protective mechanism, often called arthrogenic inhibition, and it can happen with no tissue damage at all. The joint feels tight, you lose range, and you assume something is still wrong with the muscle.
Picture someone coming back to the bench press after a rotator cuff injury. For the first few weeks, the bar path is a mess. That’s not weakness. That’s a nervous system that still remembers the injury and won’t let the shoulder move freely until it trusts it again.
Stretching the “tight” muscle harder rarely fixes this. Proving to the nervous system that the joint is safe and strong in that range does.
Do activation exercises actually work?
On their own, no. In the right place, yes. Activation alone means nothing. Doing glute band walks because you saw them on social media won’t change your squat.
Here’s how it works when it’s done properly. A common breakdown in the squat is the knees caving in, which means the hips aren’t holding their position. We isolate that job, pushing the knees out and turning the hips outward, and strengthen it. Then we go straight into the squat. There’s a principle behind this called post-activation potentiation: a muscle’s last contraction influences its next one. Work the function, then use it in the real movement while it’s primed.
That is the whole method: assess where the movement breaks down, strengthen that specific function, then put it back into the full lift that matters for your goal. Skip the last step and the activation is wasted.
Why does heavy training need smarter programming?
Because your nervous system has a limit, not just your muscles. A bodybuilder can do 28 sets of 10, wake up sore and train again the next day. A powerlifter takes nine lifts at a competition and feels flat for days afterwards. Those heavy attempts hammer the nervous system far more than the volume ever did.
That’s why I think powerlifters often program better than bodybuilders. They understand that going to failure on a biceps curl and going to failure on a heavy deadlift are not the same thing. A good program respects both.
Does technique really matter?
Yes, and here’s the simplest reason. If your technique changes every session, you’re changing the most important variable in the lift. Did you bench to your chest today, or stop five inches short? Wide grip or narrow? Pause or no pause? If it changes every time, you can’t measure progress, and you can’t tell what’s working.
There’s a safety reason too. In a squat, your hips decide where your knees go. Any drift, knees caving in or the torso tipping forward, is an energy leak, and leaks are where joints take load they shouldn’t.
Shant uses the car industry as the example. Traction control was developed at the top, in Formula 1, and it trickled down to the Corolla. Nobody argues everyday cars don’t deserve it. Same with technique: if this is the best and safest way to squat, I’ll teach it to a 60-year-old who struggles to get off the toilet seat as well as to an elite athlete. For them, that squat is their maximum effort.
Why keep the standard high?
Because lowering the standard doesn’t make anyone better. Part of my assessment is an overhead squat. Most people can’t do it well. That’s fine. It’s information. I start from the ideal and map backward to the exercises that get this person, with their constraints, closer to it.
People push back: “Hardly anyone can do that, so why try?” The answer is that it is achievable. It just takes a coach who knows the route, a sequence of exercises, and some patience. Months, sometimes longer. Keep the ideal. It’s what builds better athletes, better trainers and better bodies.
What should you do about a nagging injury?
First, rule out real damage. If the pain is sharp, came from a specific injury, wakes you at night, or comes with numbness, pins and needles or weakness, see a physio or a doctor before you train it.
If it’s an old niggle that just won’t settle, stop hunting for the one muscle to blame. Get assessed, find where the movement actually breaks down, strengthen that function, and put it straight back into your training with consistent technique. That’s how we work with 1:1 personal training at our Abbotsford studio in Melbourne, starting with the assessment I walk through in what happens in a personal training assessment. To have yours looked at properly, book a consultation.
Frequently asked questions
Can you switch on your glutes?
Not literally. If you can stand up, your glutes work. “Switching them on” is shorthand for increasing how much your nervous system drives them in a specific movement, like keeping your knees out in a squat.
Why does an old injury still feel tight after it has healed?
Your nervous system can keep protecting a joint after the tissue has healed. It stiffens the surrounding muscles like a natural splint and limits range. Strengthening the joint in that range shows it the area is safe again.
Do activation exercises work?
Only when they target the specific breakdown found in your assessment, and only when you go straight into the full movement afterwards. Activation for its own sake does nothing for your lifting.
Does lifting technique really matter?
Yes. Consistent technique is the only way to measure progress, because changing technique changes the lift. It also stops energy leaks, like caving knees, that put load on joints that shouldn’t take it.
When should I see a physio instead of training through pain?
If the pain is sharp, came from a specific injury, wakes you at night, or comes with numbness, pins and needles or weakness. Get it assessed first, then work with a coach on rebuilding the movement.
