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Hi my name's Jo Gibson and I'm an upper limb rehabilitation specialist. I've been incredibly fortunate in my career to spend a lot of time helping people with shoulder pain and instability. I've spoken a couple of conferences and have been asked to talk about the kinetic chain on quite a few occasions, and it's particularly topical cause I had a couple of patients in both of whom had what's sounded like really good physiotherapy, very thorough, every shoulder exercise you could think of, and yet they still couldn't get back to doing the things that they wanted to do. Now it's a real privilege to be asked to problem solve people, but again, it's very important to hear the whole story and understand all the things that could potentially contribute.

Case studies - 2 tennis players

But the story's very much the same in both of them. They were both keen tennis players both had anterior shoulder pain, both had an 18-month history. And essentially hadn't got better. They get to the point where they could play some ground strokes, but service was still an issue. And despite endless shoulder exercises and messing around with technique and various other things, they just hadn't got back to doing what they wanted to do.

Now, as I said, I was really fortunate. I was involved in a consensus document, a Delphi study that's been published by Lluch-Girbés 2023. So it was really interesting. It was a group of clinicians, about 40% of them were from the states where if we're honest, a lot of the researchers come from in terms of the kinetic chain. And it was really interesting to see people's biases and when they thought it might be important.

Kinetic chain

When we looked at kind of definitions of what we mean by the kinetic chain, essentially there was a general consensus that we were just referring to that coordinated sequencing of activation, mobilisation and stabilisation of all the different body segments to produce power or completed dynamic activity.

There was a kind of alternative definition, which was very much around the complex interaction and coordination of body segments, which is very much task specific, but also importantly when we talk about treatment options also relates to the generation of force and the transfer of that force efficiently through the system.

Now, when you consider that anywhere between 50 and 80% of the power of some throwing actions, comes from the lower quadrant and the trunk, it's probably not surprising when I have two athletes like this that are doing their tennis serve and obviously using their shoulders, a funnel of force and very dependent on that generation from force, from the rest of the body, particularly in their service action that actually, if I only look at the shoulder potentially, I'm only looking at kind of 20 to 50% of the problem.

When to consider the kinetic chain

Now in this consensus document, when we were trying to consider, when would you want to consider the kinetic chain, there were four key things that basically the kind of experts dealing with sports people particularly thought were relevant. The first was that the patient had a history of previous lower quadrant or spinal pain, and that's well supported in the literature as we have numerous studies now showing if we look at athletes who've had a knee or ankle injury.

If you follow them up over a three year period and compare them to an age match control group doing the same sport, then their risk of having a shoulder injury is two to three times greater. Now, of course, we are not saying the lower limb injury caused the problem, and the fact is if they've had one injury, they're more likely to get another one anyway. So we have to be sensible. However, if they've had a previous injury and depending on how it's rehabbed, that's definitely one thing that I need to consider.

The other thing that was pretty well agreed was that essentially if you have an athlete who's got repeated shoulder issues where the story is they do very well with their rehab, they go back to do their sport, they might be able to do it for a little bit longer before their shoulder becomes a problem. But there's still this consistent message that when they start loading it, if they have any increase in load or change in activity, then the shoulder starts to complain again. The other two things were a loss of performance. And as we know, a loss of performance often precedes patients presenting with symptoms that get related to SLAP lesions.

And then generally the consensus group thought that just being involved in overhead sport generally was a good indication that you might need to consider the rest of the kinetic chain. Now, in terms of what to assess, no great surprise, you need to see them doing their sporting activity and seeing if there's anything obvious subjectively, of course, we have to do the basics in terms of making sure they've got good cuff strength, making sure in terms of ratios of external rotation to internal rotation, we can't ignore the basics.

But what was really interesting, this consensus, particularly given what bad press the scapula gets at the moment, was not looking at the scapular in open changes, kind of active range of movements, but actually looking at congruency during loading activities. Now again, we could have a big discussion as to how relevant that is, and we don't have a lot of evidence to support it at the moment, but it was an interesting observation. And then the final thing, no great surprise, was to consider doing some lower quadrant performance tests, purely again to see if there are any deficits. And you can imagine if an athlete's had a previous injury, then that would make a whole lot of sense.

Now, for me, if I've got these two athletes here, one of them did have a previous history of repeated ankle sprains on their contralateral limb as opposed to their service arm, the other guy had just got his symptoms after increasing what he was doing, strength and conditioning wise, and for whatever reason, just hadn't been able to get back to his previous level without exacerbating his pain. So two slightly different scenarios, and I'll talk a little bit more about those in just a moment.

Screening tests

For quick screening tests, because obviously in the clinic, I want to think how far am I going to look into this? I've looked at active movement, I've made sure they're not stiff. I've looked at their rotator cuff function in isolation. I might get them to demonstrate their sporting activity, but how do I have a quick screen to see whether I think that lower quadrant might be relevant?

The first thing is just looking at one-leg balance and a one-leg squat. Ben Kibler did some really nice normative data around this in different age match populations, and essentially what you're looking at is do they fix through the affected arm when they're standing on one leg or doing a squat? Is there an obvious kind of protection of the shoulder when they're doing that? Now, of course, it's a tiny little window that might mean it's worth me looking at that lower quadrant further. But another really nice quick screening performance test is just doing a single leg heel raise. Now again, we have lots of normative data in different sporting populations, but on average you'd expect somebody to be able to do 30, 35 if they're doing sport regularly or at any level.

So that's a really nice way for me to do a comparison side to side and see if there's any deficits. Now in my guy who'd had a previous lower quadrant injury, repeated ankle sprain, when he stood on that leg and did a small one-leg squat, he really fixed through his shoulder as he was squatting down. So I'm thinking, okay, let's look at your heel raise.

We look at the heel raise, and actually he could do 35 on his unaffected side, no problem at all, but fatigued after 12 on the ankle weight had repeated sprains. And unsurprisingly, his balance wasn't too hot on that side either. Now I always think we have to be a little bit cautious when we look at balancing people with shoulder pain because essentially, whilst we have. Studies showing very clearly that with balance measures and also things like the lower limb star excursion tests, there are definitely abnormalities or poorer scoring in people with shoulder pain compared to age match controls. But the problem is, if you have shoulder pain, you're not going to use your balance mechanisms, your writing mechanisms in the same way because potentially pain will inhibit that.

So as ever, we have to be a little bit cautious in terms of interpretation. Now, when I look at these two guys, What are the other things we know when people have had pain for a long period of time, one that they can get into the habit of protecting their shoulder. And so get very stuck in those protective strategies. So that could be conscious. I think there's something damaged. So when I go into those risk positions consciously, I'm tightening everything up to try and protect it. It could also be non-conscious, I've just got into the habit of anticipating pain. And that pattern of protection has got really established. You think both these people have had symptoms for 18 months. When we look at the evidence, we see very clearly cortical change. That one that can be very cognitive related in terms of what I just described with fear, but also because of proprioceptive changes and just that habit of movement that can get very well established.

Now if we look at how that might manifest, we have some lovely studies. Liam Owens, who's a emerging researcher at Hope University in Liverpool that I've had the privilege of working with is just finishing his PhD and he found some really convincing links between a loss of the segmental sequencing. Some changes in terms of how athletes wind up their rotation through range.

Objective measures

And you might be thinking, Jo, that's all very exciting, but what can I measure? And actually what we see is a very clear message that reductions in thoracic rotation over a season actually link very highly with some of these changes in segmental rotation.

Now guys, we've got to be very careful, because while we have evidence that shows us that lower quadrant injury, poor lumbar pelvic stability, poor lower quadrant performance tests can make somebody doing overhead sport more likely to get shoulder pain. We need to be cautious claiming that's causation. It's definitely a correlation, but remember when we look at sport injury generally, it certainly injuries more highly correlated with change in load, changes in sleep, psychosocial stress, previous injury, et cetera. So we do need to be a little bit honest about the potential relevance when we look at these two patients. Now, so if we go back to these two patients, I've got some key things. I've got my screening test that in my ankle instability athlete definitely showed some deficits in lower quadrant performance. When we then looked at his service action, that was having an impact on how he was generating force of his shoulder, when we looked at some old videos, he was much better, with much more knee flexion, a wider stance that essentially was allowing him to build up more momentum and then push that through his shoulder. Because of the ankle sprain, he'd narrowed his base of support and essentially didn't have as much time to wind up the power, but equally was getting tired. So he reported this consistent picture. He could do a few games of tennis and then it became really sore at the front and he'd had to stop, be horrible the next morning, settle over a couple of days, and the same thing would happen again. So what did we do with him? We did some balance work. We did some lower quadrant capacity work, but then we also exaggerated that and talked to his coach about maybe looking at the things he was doing before his injury and then seeing whether we could, might make life easier.

And essentially from his ankle sprains, his shoulder problem was actually only about a six-month gap. So working on his lower quadrant capacity and then liaising with his coach about how we might just give him a bit more time to wind up that power definitely made a huge difference with this guy. Now, the other patient I told you about was really interesting because essentially I did my lower quadrant performance test. He raised 35 on each side. Something, I better look a bit closer. We can look at hip rotation and again, if we get changes over a season, that can correlate with fatigue in the hip muscles. And again, we know fatigue in the hip muscles puts more load on the shoulder. But again, his range of movement was fine. So then I asked him, I said, what do you think's wrong with your shoulder? And he said, I don't really understand. I've done all this physio, it hasn't got better and essentially I'm continuing to have problems. So tell me what else is going on in your life? And this guy had all sorts of stress going on with a relative that was terminally ill.

He wasn't entirely sure that tennis was the thing for him, because let's be honest, it's a really demanding sport. It requires travel, lots of money. He was worried about the financial stresses it was putting on his family. So there was a whole backstory in terms of things that were potentially driving other contributor to his problem.

Now, as I say, in terms of performance, I couldn't find anything terribly convincing other than he was a bit stiff in his thorax. But interestingly, when I then watched him doing his tennis, he adopted this protect strategy and wasn't winding his arm up. He was almost anticipating end range. And so the consequence was he was almost destabilising his shoulder. So what do we do? We obviously talked about the impact of all those other potential things on his pain and why when there was a change in load or things were more stressful at home, he seemed to have less tolerance to doing those things as part of his game. We also talked about how we could make life easier for the shoulder in addressing that bigger picture in terms of his sleep, his stress, et cetera, but also importantly, potentially just make him a little bit more, sequencing that force transfer a little bit more efficient.

And what's lovely is we now have a couple of papers that show us if we add the kinetic chain to our shoulder exercises, it translates into what they're doing in their sport.

So if you like, it makes them more efficient. It reinforces that sequencing. And that's a very long-winded way of saying we just exaggerated thoracic rotation and that lower quadrant combination and probably distracting him a little bit about anticipating that pain at end range. And we translated that into everything he was doing.

Now, one of the great ways of doing that initially is to get people integrating lower quadrant knee flexion extension with thoracic rotation, but do it with both hands. So you can do it with pulleys, with cables, with TheraBands, whatever you want to use. But the advantage of doing that is you have to rotate your thorax.

So if you've got somebody out here trying to protect themselves, it's a really good way of getting them out of that habit. But I think really what these two patients taught me, and the reason I just wanted to mention the kinetic chain tonight was not to say it's the magic solution. We see this increasing theme at the moment, but when we look at our patients with shoulder pain that don't get better, it highly correlates with sleep.

It highly correlates with lifestyle factors, and it highly correlates with psychosocial stress, but also things like your job satisfaction, your locus of control, et cetera. However, we need to be a little bit cautious because certainly when we look at a sporting cohort or somebody who regularly overloads above head, there is some emerging evidence increasingly to support the relevance of the rest of the body.

As I say, I'm not saying it's causation, but what I am saying is it definitely potentially makes life harder for the shoulder. And again, we have nice papers showing if we fatigue the lower quadrants, essentially the impact is the shoulder has to move through a greater range of movement and almost create more speed at the end of release to make up for the deficits elsewhere in the chain. So again, that potential overload of that anterior system.

So if you like my little guy, he'd had the ankle sprain, pretty straightforward. We just made sure he'd got the capacity, made sure he'd got the balance, and then built that into his shoulder rehab.

My other guy, there was a whole lot of psychosocial stress, a whole lot of fear. And a poor understanding of what was happening with his shoulder. Now, I'm not saying the clinicians he'd seen before hadn't given him a good explanation, but for whatever reason it hadn't resonated with him. And certainly when I'm problem solving patients, one of the first questions I ask is, look, you've seen a whole lot of healthcare professionals. They've all given you an explanation of your pain, what's your understanding? And when somebody says to me, I don't really understand, that doesn't make me think, oh, the others did a bad job. It just makes me think for whatever reason, it's not resonated with this athlete. So I need to get to the bottom of it. And as you heard, there was a whole lot of stuff going on in this guy's life. And he actually turned around to me after the first session and said, I'd never really considered how all these other things might be influencing my shoulder, but now I think about it when X, Y, and Z have happened, that's actually when I can only do a couple of games before it's problems.

When I've had a better week, actually, I can usually play four or five or six or even a couple of sets. So again, often shining a light onto those things, it might manifest as a protective pattern that's affecting his load transfer but fundamentally, I can give him all the capacity in the world, it just means he'll be able to do it for longer before the system breaks down.

So guys, a couple of interesting patients that got me thinking this week, but also allowed me to just highlight that Lluch-Girbés' paper, a nice simple read. It is a consensus from some really cool people that it was really great to be involved with. But I hope it's given you some food for thought.

If there's anything you want me to speak about particularly or something that's causing you headaches, then please just drop us a line on the Facebook page . Bye for now and thanks so much for joining.