This blog is a review of the Pacey Performance Podcast Episode 385 – Paul Comfort

The majority of the episode focuses on isometric training.   Due to the amount and quality of information the full podcast review will be split up into two parts.  This is a Part 2 of 2, which will focus on practical applications of isometric training and eccentric training.   Click here to read Part 1.

Paul Comfort

Paul Comfort is a Reader in Strength and Conditioning and programme leader for the MSc Strength and Conditioning at the University of Salford, and is this week’s guest on the Pacey Performance Podcast. He’s here to talk to Rob about isometric testing and training, and why there has been a recent resurgence in its popularity.

Twitter

🔊 Listen to the full episode here

Isometric Testing & dynamic performance

”So if you look at something like the isometric mid thigh pull or the isometric squat, there’s a huge number of studies out there that show strong correlations between your ability to produce very high forces, so the peak force or peak force relative to mass, and performance in other dynamic strength tests or tasks. So 1RM squat, 1RM deadlift, snatch, power snatch, clean, power clean performance, etc. And in weightlifters, they’re almost perfect correlations, which isn’t surprising because they’re so used to getting into those positions for the isometric mid thigh pull.  But even if we look at how they relate to things like sprint performance, jump performance, there are still strong correlations there. Now correlation doesn’t mean cause and effect just because there’s a strong correlation. It doesn’t mean if we increase peak force in an isometric mid thigh pull, you will increase your 1RM performance or your sprint performance.

However, there are a few studies out there that do indicate that as your peak force increases, your ability to accelerate increases. Or as force at a specific time point increases, your ability to accelerate during a sprint or a jump, etc increases. Now that makes sense if we go back to your basic biomechanics, because we know that it’s your relative net impulse, with impulse being force x time and relative meaning dividing it by your body mass. As long as your body mass stays the same, if you can increase the amount of force you produce in the same given time point, your ability to accelerate will have increased.

Now when we evaluate it in a isometric task, then we’ve got to hope that the athlete can actually use that force and still produce a higher force in the same time frame when they perform their dynamic task. But if you’ve got the right balance between what you’re doing in the weight room, and their skill specific training, the sprint drills you might do, the jump training, the bounding and plyometrics. If you’ve got the right balance there, you should get that transference. No amount of work in the weight room will immediately transfer to a really highly skilled task. But even just on observation, if you get somebody much stronger and their peak force goes up and then their force at 150 milliseconds goes up, their ability to accelerate when they’re sprinting, jumping, does start to improve.

There is sometimes a lag time. So the problem with some of the research is that you do a four week or a six week block of training. You get to the end of that block and you retest them [without doing a deload first]. Well, actually, if you’ve used progressive overload, which we should all be doing, you’ve had a progressive increase in possibly load or intensity, definitely in volume. And therefore we’ve added fatigue across that few weeks of training, whether it’s four or six weeks. And you look at some studies, there’s not an unloading week, there’s not a deload week, but that’s what we do when we train people normally. You have an accumulation of fatigue during that three, four, five, six week buildup. And then we have a week where we back off, we deload, we taper, whatever term you want to use for it, then retest them when fatigue is dissipated.

And the reason I mention that is if you look at a lot Dr. Andy Fries early work on overreaching, over training, they really battered people. Some of their training programmes, you look at them and think how the hell did people get through that? And you find that peak force or their maximum strength is pretty stable. It doesn’t decrease dramatically. You can push people really hard and maximum force production doesn’t go down. But their ability to produce force rapidly decreases. So if we’ve got a similar approach where we’ve got a progressive increase in volume and we then test them right at the end of that block, it’s not surprising that you’re going to see a slight decrease in their ability to produce force rapidly because they’re fatigued. So we need that appropriate deload or taper before we retest.

And it doesn’t always happen within the research. Partly due to time constraints, partly due to them getting the athletes to actually take a bit of time off. And sometimes because people just don’t know any better, which is problematic in itself. So, there is that strong correlation, but it all comes down to your ability to produce force, high forces in a short duration, which is why it’s so important to have that. If we do an isometric testing to really try and quantify how much force they can produce in a certain time point, because that will indicate that they can generate a greater impulse and therefore if they can apply that greater impulse during sports specific tasks, we will get greater acceleration, whether that’s of their mass or whether that’s of an object they’re throwing or whatever it might be.”

Isometric Training

”Transitioning to the isometric training side. So as you’ve said right at the start, this is a complementary method of training to your traditional strength training, but just taking it back again, what are the benefits of isometric training and what areas does it plug that traditional strength training maybe doesn’t?”

”Well, I think one of the things that’s really useful is it’s minimally fatiguing. So because you are actually not moving through a large range of motion and you can easily control the duration of each isometric muscle action, you can minimize fatigue. It doesn’t have the eccentric component in there, which we get with traditional strength training, which while really beneficial, actually, if you are using an unfamiliar task may cause muscle damage, may cause DOMS, pain, inhibition and that’s one of the concerns with athletes when you introduce a new stimulus is if they come back in a day or two later complaining to the medical staff that they’re really sore. Some of them, if they’re not used to that type of training, we’ll be saying they’ve pulled the hamstring or they’ve pulled the groin or whatever.  No, you are just sore because you don’t train hard enough.  That’s what happens most of the time. It’s unlikely they’ll have pulled something in a structured weight training programme or resistance training programme if you’ve been appropriately progressive in nature. So it’s not as fatiguing.

And then the other benefit is everyone has sticking points during certain exercises. You start trying to do a squat, a deadlift, if you fail, there’s always a specific point you’ll fail at, normally somewhere midpoint through the range of motion, depending on where your weakness is. So you can train people in those weak positions and that can help them get through those sticking points.

And you can do that without adding a huge amount of extra volume. But as I mentioned earlier, and as you’ve just restated, it isn’t a substitute for your standard resistance training. Otherwise you’d have to train at so many different joint angles to get that transference throughout that full range of motion that you’d end up with all sorts of issues in terms of time.  For example, I’ve been trying to do an isometric squat. It’s taken me an hour to get all these different positions for enough repetitions with enough force while that was really counterproductive because I could have done that just with a few sets of squats doing a dynamic squatting type task.

So, you know, there are some benefits, but you’ve also got to take a step back and think, what do I really need from this?”

”What does the research say around that transference of specific positions? So if I’m training at a particular angle, what’s the transference?”

”Well, a lot of the early research seems to indicate that you’re looking at plus or minus 15 degrees from the joint angle you were training at. And that seems to be correct if you are just doing isometric training. Some of the more recent studies that have been published seem to show a slightly greater range, but that is when they’re combined with dynamic heavy strength training. So that probably helps with that transference, because you’re still doing other training and that’s the problem you get sometimes when we’ve got to do really well controlled studies in very controlled environments so that we know that whatever our intervention is, is what’s had the effect.

But then we also have to do those studies where they’re more ecologically valid. They are what we would do in an applied environment. So they are what we’re going to do with our football team, with our rugby team, with whatever that sport is. And then that’s when we seem to find that either what was done in that control lab environment doesn’t work or it doesn’t work as well; or sometimes, oh my God, this works much better because it’s in addition to other types of training. Some of the early studies on isometric training showed an increase in rate force development, but a decrease in jump performance. Well, how does that work? You would assume that if your rate force development increases, your jump performance should increase, but actually they were assessing rate of force development during a single joint isometric task. And then comparing that to jump performance where you’ve been training at zero velocity for the last six weeks.

So, and your jump height is determined by your velocity at takeoff and you are used to training at zero velocity. So is that really surprising when we think about specificity of training that your jump height decreased? No, it’s probably not. But again, look at the studies where it’s combined as an addition to your normal training and we tend to get beneficial adaptations. And it’s not just about the performance side of things, there’s a lot of research showing the benefits for isometric type training. As an analgesic, if you’ve got tendon pain before training in competition, actually to create adaptations in your tendons to make them stiffer, to increase the amount of collagen, etc. So they’re more resilient to stress strain and therefore injury.

However, bear in mind a tendon doesn’t know what type of muscle actions are occurring. It’s just got stress and strain applied to it.  But the benefit is it’s very, very controlled when it’s isometric. And if somebody has got a bit of pain, you can ramp that up progressively. Whereas it’s not quite the same because you suddenly throw them into a plyometric task.”

”If you look across the research, it’s pretty varied. I don’t think there is a true consensus because the studies are set up to get different results. Some are tendon related, some are for performance. If you think about it practically, if you identify where someone’s weak point is, that point that they slow down,  unintentionally during an exercise. So if you are going to use an isometric squat to supplement your dynamic squat training, find what that sticking point is. Find the point that they’re really having to grind through and you don’t need to assess velocity of the movement. That point with a heavy load where they really start struggling, we can all see that. They can tell you that posture. They know it because they thought they were going to fail at that point.

That’s the point that their face goes purple as well. So it’s really easy to spot. So actually doing some repetitions, not necessarily for a prolonged duration because you still want a really high effort. And again, the problem is if we do a really prolonged duration and a near maximal effort, we will induce fatigue. So you’re looking at your three to five second efforts, we know that you should be able to achieve peak isometric force in under two seconds. And from looking at all the forced time data that I’ve collected with isometric squats and mid thigh pulls, within five seconds, everyone’s force production starts to go down. So if you’re looking at a three to five second effort near maximum, I personally find that to be one of the most effective ways of getting people to get through sticking points. And we also want to train our athletes to express force rapidly.

So actually doing really prolonged holds may be grate for rehabilitation purposes. And if somebody’s had a niggling injury and that’s continued, that might be really, really beneficial, but from a performance point of view, doing three to five repetitions, three to five seconds per effort. And if you can assess that with a strain gauge or with a force plate setup, that will give you some additional feedback, but even without that you can tell if they’re working hard or not.  Watch an athletes’ face, are they holding their breath? Are they gasping for breath when they finished a repetition? Are they shaking during the task? Most people will. So you can see most of that without the strain gauge or without an isometric mid thigh pull. But actually if you’ve got the force plate to do this type of testing during their training you can also get people really competitive.

So if you and I were training, we can both, if we’re sort of a similar stature, we can both get onto a force plate, and do an isometric squat. I do a five second effort. Step away, you do a five second effort and we compete against each other. You’re really going to get maximal buy-in and maximum intent then. And you might not need to do it with your whole squad. There may be some athletes you think, right, this will be really useful for them. And again, a good way of sort of judging those joint angles based on where you perceive their weaknesses to be. And that’s easy during some of those dynamic strength exercises. You’ll really see that.”

Eccentric Training

”I’m just conscious that we’ve talked about isometrics been supplementary and not to miss out eccentric and concentric contractions, which you’ve mentioned as well. So where does eccentric focus training fit into this and what are the benefits? What we can gain from eccentric training?”

”So with eccentric we can again get really, really high forces being produced. We’ve got to implement that eccentric load appropriately though. And I’ll come to that in a moment. We know that if you’ve got a high eccentric load, which is greater than the load during a concentric task, that we can increase fascicle lengths. And if we can increase muscle fascicle lengths, we increase the potential for those fascicles to shorten at higher velocity. So I’ll try not to go off topic here, but if you look at the force velocity relationship, the majority of people get that wrong and I’ll hold my hands up. I’ve probably made that worse with some figures I’ve put in publications, textbooks, etc, but the force velocity relationship comes from fascicle shortening velocity and individual fascicles and the amount of force they can generate.

It’s not movement velocity, which is how most people interpret it. So it’s how quickly your fascicle can shorten. Now if your fascicles shorten more rapidly because they’re longer and you’ve got the optimal pennation angle for that, you will undoubtedly get a higher movement velocity from those individuals.  Eccentric training increases fascicle length because you are getting the muscles being stretched while it’s producing a high force. And that’s the key. You need a high force, so you can do tempo type eccentric training. We can get people lowering down over a prolonged period of time. That increases time under tension that may create a hypertrophic stimulus where we get more muscle mass. But it’s not truly eccentric training.  You’re moving at a really low velocity. 

[Personal communication with Paul: ”it’s not truly eccentric training because as was stated earlier, a high eccentric load has to be one which is greater than the load during a concentric task, in order to increase increase fascicle lengths.  tempo training prescriptions are usually around 80-85% 1RM for 3-5 seconds lower and you the lift it back up concentrically.  This is a good introduction to the controlled tempos but the load is insufficient to overload the eccentric component.] 

The goal of eccentrics is to get a higher force at a higher velocity but how you train that in the weight room is focus on the higher focus component. Imagine trying to squat down quickly with a high load.  That doesn’t happen if you are squatting and you put extra weight on the bar. If you want to move at high velocity, you relax and gravity accelerates you down. You can’t move any quicker than just relaxing and letting gravity push you to the floor. With safety bars and stuff like that in your power rack, obviously you don’t want to get squashed or crush your athlete.  So the key thing is if you are trying to apply really high force or using a high load, the eccentrics in that situation with multi-joint movements need to be slow and controlled.

Personally, if I’m doing it and I’m trying to use an eccentric overload, I’ll do a front squat because it’s so easy to drop the bar rather than a back squat. You’ve got to be good at jumping out from under that bar if you start to move too fast or have it set up inside a rack with the safety bar set just around your minimum squat, your maximum squat depth, the minimum height you’re going to achieve.

They’re really, really beneficial, but again, as an addition to your normal training. Now, if you’ve got no equipment and I’ll just stick with a squat as an example, because it’s probably the easiest one. If we want to create eccentric overload, go above your 1RM, set those safety pins. Go to about your maximum squat depth and do a very slow controlled squat. Probably going to take three to five seconds to get down there. If you think about when you’re going for a 1RM anyway, you squat down slowly. You don’t go down rapidly, because you’re going to get squashed. So you go down slow. If you’ve gone 10% above that (concentric 1RM), you’ll go down slower. The only problem is then you need a couple of strong people to lift that bar back up or you need to unload it and then lift it backup.

So it’s not always practical. There are some commercial devices on the market where you can do that and it’ll winch it back for you. But most people won’t have those. The other option is to use weight releasers, the j hooks that hang on the end of the bar, you can put weight on it. You get to the floor, they’ve got an angle on them, so they’ll actually flip off when you get to the bottom. Just make sure you set the height of those weight releasers, five to eight centimetres longer than you need so that when you get to the bottom of your squat or whatever lift you are doing, that they do release and make sure you’re symmetrical when you squat down because if one comes off one side and not the other, you’re in a whole world of trouble there.

So practice it with the warm-up weights and slowly build up. And you’ve got a whole range of things you can do with that. You can do it to almost try and potentiate or enhance your propulsive phase. So you could put 80% of your 1RM on the bar, 30% of your concentric or your traditional 1RM on the weight releases, you’ve got 110% 1RM. Squat down, then release, and then you come up as explosively or fast as you can. You can use it for hypertrophy as well. So we get that increased time under tension on the way down and we can use it for actually just getting that higher eccentric stimulus. As long as you squat, you get back to the top and then two people hook the weights back on for you.

The nice thing is for that you can end up doing that as a cluster set. Somebody put the weights on, you then pick the bar back up, step back, squat again. It takes a little bit longer, but actually you do less volume if you’re doing that high loads eccentric type training because it does create some muscle damage.

Now the other thing to bear in mind with this is that muscle damage is not a bad thing because it gives you the repeated bout effect. And it’s not just from eccentric training. You get that just from a novel stimulus. So if you’ve been focusing bilateral training, front squat, back squats, deadlifts, and you suddenly throw in a load of split squats, lunges, rear elevated split squats, you’ll ache in different places. The next day you’ll feel it more in your glutes and you groin, etc, because you’re stabilizing.

That’s not because it was a much higher load. It might have been a lower load overall. If you work out the total load lifted, it might be a lower volume. But it’s a novel stimulus. So when you introduce a novel stimulus, whether eccentric or whether they’re just going from bilateral dominant to unilateral, ideally build it in progressively because you will get a little bit sore, but that initial bout of, especially if it’s eccentric training, protects you against some of that muscle damage and the soreness and the inhibition during the subsequent bout. So your first bout, do a really low volume. If you’re doing it with squats, maybe do it on your first repetition of a squat or weight releasers. So if you’re training at 80% of 1RM, you put that extra 30% on, so you lower 110% your 1RM.

Do do it for one rep. Your first rep of a set and do it on the first rep, maybe the three or four sets. That is likely to give you a protective effect. Next time you can do it within the set. You know, you can cluster your set. If you’re doing sets of six, rep one as the weight releases on, then you do two and three normally, rank the bar, put the weight releases back on, do rep four with the weight releases five and six or without you’ve doubled the volume of eccentric training. So build it up progressively, because the last thing you want is your athletes coming back in telling you how much they’re aching the next day, turning around to the coach saying that they’re in bits, turning around to the medical staff because they won’t want you doing that type of training again, but it can be really beneficial.

And the few studies that are out there that there’s one by Mellissa Harden, where she used a control group trained athletes and some very well trained athletes. It was some GB cyclists, and they showed within a four week period substantial improvements in maximum and rapid force production from doing that type of training, using an eccentric leg press. Now there is an issue with that. No one else has access to that eccentric leg press apart from British cycling, but hey it worked. It shows, you know, the theory holds true. There’s a couple of studies by Simon Walker, which I think both Rob Newton, Keijo Häkkinen and Gregory Haff were part of that research group at that point, looking at different types of eccentric training in a more applied environment, more ecologically valid. So not just isolated, single joint eccentric training. And again, they’ve shown big increases in a short duration.

But again with a relatively conservative loading paradigm that they’ve used and I think that’s the key thing is you have to do a small amount because we know it will create some muscle damage. So be conservative with it. A lot of the research, researchers will say, we need to get this stimulus. We need to make sure it has a positive effect, but you know, if you turn around, look at some of the early studies on Nordics where they were doing 50 plus repetitions in a week, or sets of 10. I know after three, my subsequent reps are pretty poor because it feels like everything’s going to cramp up. And we now know that those lower volumes are maybe not quite as effective, but you get much better adherence and longer term, they will be more effective.

So you’ve really got to be conservative with how you apply that eccentric load. There’s lots of different ways to do it. But there are some pretty simple and easy to apply options in a normal setting if you haven’t got specialist equipment. And the weight releasers you can buy those for probably 200 pounds or if you know anybody that’s good with metal work, they can probably make some for you.”

Top 5 Take Away Points:

Paul Comfort Research Gate

This blog is a review of the Pacey Performance Podcast Episode 383 – James Moore

James Moore

James is the leader of the specialist physiotherapy team at the Centre for Health and Human Performance (CHHP) in Harley Street.  James has 25 years of experience in physio, graduating with an honours degree in physiotherapy from Kings College London. He was Clinical Lead Physiotherapist to the English Institute of Sport, with a special affiliation to UK Athletics. He spent a period of time working as Head of Medicine for Saracens RFC, before moving on to manage the intensive rehabilitation unit (IRU) at Bisham Abbey for British Olympic Association and was Head of Performance Services for the British Olympic Association and Deputy Chef de Mission for the Rio 2016 Olympics and beyond. He is currently in clinic two days a week and also has a number of consultancies including with Andy Murray.

Twitter

🔊 Listen to the full episode here

There is no substitute for what is in essence four years of competitive play, if you go back to 2016 I think he played 87 matches when he was world number 1 and last year we played about 40, so we are at about 50% and so you need to build that tolerance up and that 10% top end fitness.

His V02max is low 60s which is great, but at his best he was low 70s (ml/kg/min).  He’s strong, he’s deadlifting 270 kg, quarter squatting 260 kg at 84 kg and can produce 1500 W on a Watt bike so physically we are in a good place and what we need to do now is transfer that into the consistency on the tennis court.  That just takes time, good coaching and continuity from the rest of the team to help him deliver.”

”Why do athletes get hip and groin pain in the first place?”

”I don’t know that we have all of the answers yet.  Do we have the exact aetiology?  [MEDICINE- the cause, set of causes, or manner of causation of a disease or condition.]  I don’t think we do.  I think we have strong indicators, for example, we know that if you play a kicking sport (football, rugby, Aussie rules, Gaelic etc) you have a much higher percentage chance (you’re probably 3 x more likely to overload your pubic joint and your adductors) than you are in any other sport.

However, when you start to shift from a kicking sport to twisting/turning sports (non primary based running sports so badminton, squash, tennis, ice hockey, short track speed skating), yes you might run as part of your conditioning to supplement the sport but it’s not a primary requirement of what you have to do in the sport.  Yes, you’re sprinting on the Tennis court but you may be covering 3 km in a two-three hour match, and we know that when you twist you increase your risk of hip related injuries.

We also know that if you run in a straight line you also really increase your risk of hip related injuries and a lot of that comes down to the cumulative repetitive force within the joint and what we know is that bones don’t like reciprocal movement- the same movement over and over again, so running in a straight line is generally one of the worse things you can do for bones.

We also know that women as a rule will have a lot higher risk of running related injuries in the hip and men as a rule will have a much higher risk of groin related injuries.  So when you put all that together, I think it’s really hard to find a place to hide on the sports field.

The lumbo-pelvic-hip complex as a unit is the hub for power creation in speed and power based athletes.  Yes, the soleus might be one of the strongest muscles in the body, if not the strongest, but when you’re really looking at peak torque in high level sprinting and running and kicking, you’re talking way over 9 x bodyweight of impact loading and in the triple jump it is 15 x bodyweight going through the hip!  So the forces are just huge and then it just comes down to capacity, tolerance and how much you can build up.  I would just call it supply and demand – there is a huge demand from the sport, and then you have got to build up the supply for the individual.

If you don’t get that right, in terms of training capacity and/or individual capacity, that’s when you’re potentially going to get an overload and injury.”

”So why are the sites of injury for males and females different, it is purely anatomical?”

”No, I don’t think it is, for a number of different reasons, although the reason why I hesitate is because there is more evidence coming out more recently starting to look at that (anatomical differences).  Around 15-20 years ago we were talking about width of pelvis and angles of muscles going into the groin, like you would talk about the Q angle of the knee and patella-femoral load, and really there was no evidence around it. So the morphological (structure of the body) may not make a difference.  Certainly the muscle mass and the forces being produced may make a difference.

There are also a number of other factors such as line of force (males tend to be more straight down and females tend to be more diagonal), angles at the pubic joint, and the anterior pubic ligaments being significantly stronger in the female, as well as hormonal profile and elasticity of ligaments in females.”

”How can we differentiate who needs surgery and who doesn’t’?’

”The decision making process around surgery becomes multi-factorial, and we certainly have advised surgery for a number of different reasons.  Certainly from a clinical point of view, there has been a anecdotal significant reduction in groin surgeries as there has been an improvement in core stability in terms of the functional load transfer across the anterior pelvis.

In football we typically see 15-20% of footballers having a groin related injury, so 1 in every 5.  The game is faster, the players are bigger, stronger, the ball is moving faster on the pitch, and it’s in play for longer, which increases your exposure.  So while we are seeing this transition we are still playing catch up with the demands of the sport.

The key really is that the physical signs should match up with the subjective complaint of pain.

If the pain is disproportionate to the physical signs then you have probably got tissue damage beyond the point of repair.  When we start to look at groin surgery, whether we are talking about abdominal or adductor surgery, with abdominals they can produce force but it’s painful and you’ve got palpable gaps or issues with the inguinal canal, and they fail a period of rehab (2-6 weeks) where there they just can’t put enough load the tissues without provoking symptoms.

You’ll genuinely know whether they are going to succeed in a programme of rehab.  We’ve looked at them and we’ve said ”this is surgery,” but they want to go down a conservative route but at 2 weeks, 4 weeks, 6 weeks they fail their markers, and so you then go through that.  That’s a really good process psychologically to let the player adapt as well as tick the box in terms of doing your strength work before you go down that route; and then there’ll be certain people who will have been told that they need surgery, but there will be some obvious deficits and when they start to load the pain subsides but the pain is usually fairly consistent with their physical signs.”

”Do athletes have to stop playing in order to recover from these kind of injuries?”

”Most groin overload injuries don’t stop you from playing but they just limit your performance.  So we will have lots of people who will just feel like they are at 60 or 80%, I can pass the ball, I can run but I can’t put some shape on the ball, and put my foot through the ball.  Everything has to be controlled, and if I do try and push it I get sharp pain, I’m a bit incapacitated for a few minutes but then it settles and I’m able to go again.

It’s very easy to manage people and keep them ticking over and then it comes to the bigger question of the relevance to the individual- if they are 80% fit are they better than the next individual coming in?

As a medic part of our job is to protect the athlete from themselves and protect them generally, but then also as a performance scientist is to push them to that red line and get them as close to that red line as possible and keep them there for as long as possible.  It’s easy to stop injuries, you just don’t train very hard, but if I want to win stuff I need to go right to that top end and push my body and that’s a difficult balance to strike.

With overload load related injuries, if we want to strip that back we need the reduce the load and then build it back up in a progressive overload manner and then you can build capacity.  So it would mean dropping them out of training, whether that means complete reduction of training or modified training (allow them to run but don’t allow them to kick) to reduce some of the markers.  So they can do part of the training but not all of the training, and it depends on the demands of the training.”

”How do we decide how to structure the rehab programme, are there some key approaches that need to go in no matter what?”

”Does the tissue that is the source of pain need to be loaded or unloaded?  I get a lot of people coming in with adductor related groin problems, and they’ve been loaded but the adductors are the strongest part of the chain when you assess it, and their abdominals and/or hamstrings are not functioning well.  So in that case, you want to reduce the adductor/adduction load and increase the abdominal/hip flexor load and maybe hamstring.  A lot of that comes down to asking where are we from a capacity and/or strength point of view which requires a little bit more investigation away from just the pathology point of view.  And that’s part of the trick of examining the individual from a pathology/pain source point of view and also examining them from a function perspective.

The adductors bring the leg across your body but they are also a significant hip flexor- and there is an argument that the adductor longus is the second most important hip flexor behind iliopsoas but they are also significant hip extensor, so once you go above 45 degrees of hip flexion they become your most significant hip extensors (and adductor longus decelerates hip extension in running mechanics).

The adductors are the main muscles that bring you out of a deep squat and they the are the main muscles of hip flexion and the adductor magnus off loads the hamstring, so maybe the adductors are over working because the hip flexor complex is not good enough, so maybe we need to bring up iliopsoas (which has an adduction moment arm).  Or maybe the hamstring and the glutes are not doing their jobs properly so we need to increase the hip extension function to take some pressure off the adductors.

So what makes it a little more complex is that your abdominals also aid in hip flexion and control hip extension moment arm, and your obliques also control side flexion which your psoas also controls, so my right side psoas is a controller of left side flexion.  So that becomes quite critical in terms of how the adductors, abdominals and hip flexors work as a unit to get a balance across the anterior pelvis.”

For every adductor load you give someone, you should give them an abdominal load to balance the pelvis.

For every abdominal and adductor load you give someone, you should give them a glute load to balance the pelvis.

1.  Hamstrings first – as they produce extension moment and adduction moment at the hip and help to control the pelvis, and if the hamstrings are inefficient the adductor load will go up.
2.  Abdominal load – in particular oblique bias including CSA of tissue not just control
3.  Hip flexor load
4.  Muscle capacity of running muscles – calves, quads and glute function as it relates to muscle capacity, and what does normal running look like technically, as if we can’t run then we are always going to struggle to kick or twist on the run?

It’s all about quads and calves

”So it’s about addressing the whole kinetic chain.  Also be cautious about having the philosophy of it’s all about posterior chain and hamstrings and glutes and a posterior bias.  If you just look at elite track & field athletes they have huge quads!  So the first point is you have to produce vertical force in order to start running and that’s all quads and calves which you need to get that right first to produce your stride length.  Then once you’ve got your stride length, it’s all about hip torque to produce your stride frequency.    Stride length gets you up to 7 m/s and hip torque gets you beyond that!”

”Would attention on running mechanics help with this return to performance following groin injuries?”

”I think we need to start with what do we think is the minimal dose that we need to apply to the individual to try and reduce the risk, and if that comes in the form of a running mechanics or another stimulus.  If the goal of a running stimulus is to improve the running mechanics and get them to move more like a sprinter I think that is really really difficult.

An elite 400 m sprinter will probably do near enough 2000 m of high quality speed work three times a week plus of all the drills which will probably be about 500-1000 m of work at the beginning of every session.   So we are then talking about 7,500-9000 m per week of high quality speed work and that’s done week in week out for about 9 months before you get to race season.  So the dosage to really get good mechanics and to really condition the tissues to that kind of load are really really high.

So maybe a footballer or rugby player is doing 1000 m of high quality speed work per match so I’m not sure you’ll necessarily see them get the same amount of dosage.  But with that being said, if our goal is to condition the tissues to increase limb speed, shorter foot contact and a cognitive stimulus to get the patterning from a central nervous system or Frans Bosch decentralised spinal reflex point of view, that is reasonable.  We’re not trying to turn them into runners, we are just trying to condition the tissue and not necessarily trying to hit the ”right positions’ from an elite sprinting point of view, but we are trying to get quick limb movement and short foot contact, where the outcome and the coaching cues will look different which is a very different coaching approach to coaching an elite sprinter on a track with spikes where you want a high knee, I want you to increase your stride length and that sort of thing.”

”Are there any key positions that you are looking for when you are observing a change of direction?”

”Different sports will have different strategies- e’g a rugby player may use muscle forces (concentric/eccentric) vs a basketball player using elastic/reactive (isometric forces).  A change of direction also looks very different if you are moving over 5-10 m and getting up to 6 m/s versus a winger bombing down the pitch at 9-10 m/s.

Look at it with a coaching eye.  Does it look efficient? Does it look effortless and free and I’d almost go back to coaching the individual and the way the individual moves and what feels right rather than getting into a very specific criteria for this is how you change direction.”

”We have different markers for different stages of rehab.

Early stage – start with clinical markers and reduction of pain such as squeeze test, abdominal load test and then can I get the abdominal to adductor ratios right (see next stage)?  Markers need to move away from pain/pathology to function around the groin so 20 kg HHD or 2 Newtons/kg force across the groin and progressing to 25 kg HHD.

Next stage – progress to running specific markers, and balancing the pelvis, looking at ratios of adductor/abdominal and adductor/hip flexor and hamstring/hip flexor ratio, so you can start to see where the weak link is.  Most elite level athletes get injured where they are strongest not where they are weakest, because they compensate to their strongest area which is the path of least resistance.    Most of the aspiring athletes get injured where they are weak because they are trying to produce force and they just don’t have the capacity to do it and don’t have the compensatory strategies.

We might also have a functional test such as split squat for indication of capacity across the pelvis.  When we get to return to running we can look at vertical force qualities, what’s their isometric squat like, peak plantar flexion force like, have they got some RSI markers we can look at?  As well as looking at the balance between flexion/extension ratios.”

Key ratios:

ADDUCTORS – 30-35 kg, and should be 60% of hip flexion, and 80% of extension.

ABDUCTORS – a little bit less than adductors- 20% behind adduction, and 60% of extension.

EXTENSION – should be primary torque producing force and FLEXION should be about 10% behind extension.  Adduction should be 20% behind extension.  You should be 40% stronger into extension than you are into abduction as a general ratio across the hip.

Look at those numbers relative to performance.  In order for the way you run and/or kick, what do we know is your norm or what is the ideal we need to get you to?  It’s about ratios around the hip rather than absolute numbers and it’s about the relative number relative to the numbers the athlete can produce in the demands of their sport demands.

Top 5 Take Away Points:

CHHP specialist physiotherapy clinic

This blog is a review of the Pacey Performance Podcast Episode 380 – Alistair McBurnie & Tom Dos’Santos – Part 2

Tom Dos’Santo

Tom is a lecturer at Manchester Metropolitan University, where he teaches strength conditioning and sports biomechanics. Previously, he’s worked at the University of Salford, and England Northwest and Manchester Thunder netball squads.

Twitter

🔊 Listen to the full episode here🔊 Listen to Part 1 here

Individualising Training

We want to make athletes better at performing these high intensity actions and to just have an insight into the volume. This player performs, you know, 200 metres of sprinting distance in a game. That’s great from a volume perspective and programming of weekly and monthly training volumes.

But in terms of how are we actually programming how are they achieving that movement (volume) and information about the movement strategies and the special temporal variables that you get from these kind of technologies I think will give us more insights into the specific drills that can target them because if we’re looking at horizontal deceleration and we uncover that a player’s ground contact time may be a bit too elongated, we’re then stripping that back and going, right, what can we do in the gym to make sure that we’re actually increasing elements that are going to improve ground contact time or stiffness if you’ll like?

So I think when we get to a point where we can move a lot of the stuff that is typically done in a lab and moving it to the field and almost ”testing without testing” players within their athletic development training programs these technologies are able to pick up every single action that they’re doing. So it becomes a point where we don’t have to worry about getting athletes in for a testing battery. It can almost be done as part of the day-to-day practices, as part of the warm-ups, etc.”

In terms of developing the qualities needed for good deceleration ability in the gym, when people look towards that, what should people be focusing on based on what we’ve just spoken about for the last 45 minutes?

”@Tom: So I think it’ll be very similar to change of direction, especially when we think about that angle-velocity trade off again. So we think the shallow change of directions, being more velocity dominant, more concentric and reactive strength dominant, whereas particularly anything 60 degrees, 90 degrees and above are probably a bit more of eccentric strength training focused.

So in terms of physically preparing athletes, we like to think about specific musculature and segments that we want to target. And then maybe think about the underlying physical qualities and strength qualities. Let’s discuss the musculature first, and then some particular physical qualities and training methods.  It should be a mixed multi-component and a multi-segmental model and It’s not just one specific area, or one training modality that is going to bulletproof our athletes.

Trunk Control

And I think the kind of the training recommendations that myself and Alistair will go through are probably applicable not only for deceleration, but change of direction, curvi-linear speeds, accelerations and high speed running. So trunk control, if we work our way down, trunk control is going to be a massive. Trunk contains approximately half of the body’s mass and that needs to be supported typically on one limb where we’re doing these deceleration and change of direction actions. And we need good control in the frontal plane and the sagittal plane.

So there’s a lot of evidence showing that from a change of direction perspective anyway, lateral trunk flexion is going to increase our knee valgus moments because we get laterally directed ground reaction force vector that increases the moment arm and subsequently increases loading.  So frontal plane trunk control is going to be massive.

Technique modification training so basically good cuing and good coaches are telling athletes to adopt a bit more of a neutral trunk posture, and make sure they are in their correct alignment. I know some people have used medicine balls to try and reinforce optimal trunk alignment. I think Enda King and the Sport Surgery Clinic have shown it to be quite effective.

Our dynamic trunk stability exercises and balance training has also been shown to be quite effective at improving frontal plane and transverse plane trunk control. In terms of correcting sagittal plane and avoiding anterior trunk displacement, probably in the opposing muscle groups and the posterior aspect especially erector spinae and glute max exercises target that trunk control and reinforce that bracing and again, instructing our athletes to try and avoid excessive forward trunk lean when we’re decelerating and performing these change of direction actions.

And there’s also evidence showing these deficits in trunk control can increase ACL injury risk and have been prospectively shown to increase ACL injury risk. So with that multi segmental model focusing on correcting that anterior pelvic tilt, getting that dynamic trunk stability in the sagittal and frontal plane seems to be key.

Hip Complex

Then, because from the biomechanical aspect during these decels and change of directions we create these large hip flexor moments and more externally applied knee flexor and hip flexor moments. So they need to be supported and counteracted with an internal hip extensor and knee extensor. So again, the musculature around the glutes, and external hip rotator strengthening is going to be key to tolerate those large hip flexor moments, trying to resist that change in hip flexion essentially. But also it’s going to be key in terms of frontal plane control particularly the femur. So again, there’s evidence showing that a knee valgus can increase knee valgus loading, like a two degree difference can increase the torque by around about 40 Newton metres.

And by having high levels of glute activation it can resist and oppose and support that potential knee valgus loading and preventing that knee valgus position. So that would be key from that perspective, but it’s also key for facilitating braking.

Anterior Aspect

If we start going onto the anterior aspect, so the quadricep strengthening is going to be key, particularly for those eccentric muscle actions and to support those large external knee flexor moments. So we’re getting internal knee extensor moment. So we have high levels of quadricep activation, but we have this kind of performance-injury trade-off. So we need the quadriceps for the braking aspect and we need them for the propulsive aspect if we want to go and re-accelerate and perform a change the direction.

However, if we don’t have high levels of co-activation of the hamstrings, this can increase our anterior tibial shear. So again, I’m going to focus on ACL injuries because I love ACL injuries, but it’s kind of like a multi-planar mechanism. So we get our anterior tibial shear, which can result in this anterior tibial translation of the tibia relative to the femur. That seems to be one of the primary contributors of ACL loading.

If we get these aggressive quadricep activation at these extended knee postures, typically within 0-40 degrees where the quadriceps insert, we can get this anterior tibial translation. So although we do need, I’m not saying we avoid high levels of quadricep activation, we do need it, but we need to make sure we get high levels of co-activation of the hamstrings as well. Hamstrings are bi-articular, originating in the pelvis and insert into aspects of the tibia and the fibular, but their role is to prevent that anterior tibial translation to try and oppose and create a posterior shear force. And again, there’s lots of evidence showing that having weaker hamstrings and fatigued hamstrings can increase ACL loading, and there are some musculoskeletal modeling showing that.

So although we do need high levels of quadricep activation, we need to make sure we get the high levels of co-activation of the hamstrings as well. And that could be a whole range of different fast eccentric velocity exercises, slow velocity exercises, isometric, eccentric, and even potentially some concentric strengthening exercises as well.

Lower Limb

If we move down the limbs, we’ve focused on the knee and the hip there and the trunk. There is a whole debate around the gastrocnemius, but the gastrocnemius is a kind of antagonist to the ACL and can increase ACL loading. There’s some evidence showing that we need to increase soleus activation, particularly around the ankle, the ankle acts like a kind of dampener and a shock absorber for deceleration and our change directions. So although we need that quadriceps, some people argue that soleus activation is key.

How you go about isolating soleus without getting gastrocnemius would be quite difficult. I probably don’t have the answers there. Probably some more intelligent people might be able to answer that. And then we also have a kind of like our intrinsic foot stabilizer muscles and that kind of perennial muscles as well to try and prevent those excessive inversion angle of velocities because lateral ankle sprains are a common injury mechanism during these decel and change direction actions. So specific exercises to target ankle stability and foot stability.

So they’re the key muscles and musculature that we want to target. I’m not saying that this is the right or only way to go about it. It’s a whole different range of methods. My whole philosophy about transfer of training is focused on the adaptation that we’re trying to elicit. I’m not going to say we must do Olympic lifts or must do this as long as you’ve got a rationale behind your exercise and we’re trying to elicit some sort of musculoskeletal or mechanical biological adaptation, that’s key.

Physical Robustness

So in terms of reducing risk, we’re trying to reduce those high risk deficits that are linked to the potential to generate multiple planer knee joint loads. So any frontal plane deficits, such as knee valgus, tibia rotation, lateral and frontal plane trunk control. So again, this is quite a performance-injury trade off. We need athletes to generate high impact ground reaction forces, but they need to be able to tolerate them. So having athletes physically robust enough, there seems to be this emphasis now and shifting away from kind of injury prevention, but more focus on physical robustness to tolerate these loads.

So again, to tolerate these potentially hazardous knee joint loads in particular, is increase muscular support round about the knee span and non knee spanning muscles around glutes, around about the hip, around the knee as well, the quadriceps and the hamstrings and the lower limb as well and they can support in some of that loading. By mechanically loading these structures, we are stimulating some musculoskeletal adaptations to hopefully strengthen those tissues, so they’re more robust to tolerate them.

And what Alistair alluded to before in terms of reducing injury risk, is that careful monitoring and sequencing in periodisation of these high impact activities. So getting into these advancements in technology, we’re monitoring a number of accels and high speed running. There seems to be this sweet spot, not too much, not too little in terms of high speed running, I think was it Malone who identified maybe six to seven sprints of 95% and above. We just don’t know from a change of direction and deceleration perspective, but we encourage practitioners to monitor hopefully these proxies of ACL and lower limb loading, and probably try to avoid these rapid spikes, maybe 10 to 20% on a week to week.

And then you’ve got the development of the kind of perceptual cognitive abilities as well. So if we can start identifying some of these cues a bit earlier, so we can make some anticipatory posture adjustments and get these high levels of pre-activation. This again should hopefully dissipate some of the loads. Probably a debatable area, whether it’s in strength and conditioning coaches’ job to work on perceptual cognitive speed, I would encourage people to work with a motor skill expert, but I suppose it comes down to working with a skills coach, motor skills experts to try and identify working on perceptual cognitive speed. So we can identify these cues earlier, put us in a position to make these anticipatory posture adjustments earlier. Give us the physical affordances to hopefully adopt these safer, and more mechanically robust strategies to reduce loading and optimize performance.

Multi-Component Training Model

Damien Harper’s has been calling it the dynamic braking performance framework we are a big believer of a multi-component model. So not a one size fits all, but including some trunk stabilization, balance, plyometric training is a very good transferable exercise for not only for improving performance, but improving lower limb control and neuromuscular activity patterns, but also get some eccentric strength development in the weight room. I encourage a multitude of different exercises that focus on all aspects of the force velocity curve. So having some fast eccentric velocity exercises, whether that’s through plyometric training, maybe some ISO inertial training or some kind of more coordination overload. Some more slower eccentric velocity exercises, whether that’s more AEL, (accentuated eccentrics loading), or I don’t know, maybe some Nordic curls, for example, or just increasing time under a tension and tempo training.

I probably encourage people to read the work of Tim Sycamore, he did a two part review. Not my area of expertise, but I know you’ve interviewed Alex Natera and Daniel Lum, big emphasis on isometric training at the moment, particularly if we could try and mimic some of the postures and deceleration and change of direction. However, we probably do need to target particularly that kind of triple flexion position in a range of different postures, because the greater the angle of change direction, you typically go to greater range of hip and knee flexion as well. So you probably need maybe a 140 degree angle, maybe a 120 degree and a, maybe an 90 degree angle with different postures. And I know there are advocates of yielding and pushing isometrics. I don’t know too much about that.

I think you can elicit some very good tendon adaptations and get something hopefully quite non-fatiguing positive tissue adaptations as well as those sports specific postures, whether it’s unilateral or split position. And then the reactive strength qualities that we could target in the weight room, our typical ballistic training, our Olympic lifts, not only during the propulsive phase, but whenever we decelerate the barbell, not getting into a debate whether we need to catch or just do the pull of variations. However, if you just do the pull of variations, arguably you get a nice fast eccentric loading, when we decelerate the bar, so that could be a really good method as well. And just your generic tissue conditioning and your general resistance training your back squats, deadlifts targeting those key segments that are target before.

And there’s finally, and I’ve talked for ages about this focus on movement quality. Essentially movement is a skill. These injuries occur due to some sort of biomechanical limitation that’s increased load into that specific joint or structure. So trying to optimize the technical characteristics and maximize performance, but also potentially mitigate injury risk. There is a performance-injury trade-off associated with some of the techniques, but we’ve shown that in as little as six weeks, we can modify athlete’s technique during cutting and turning by giving some externally directed verbal cues and introducing these in the field, as part of a field based warm-up.  I don’t buy that athletes and coach said they haven’t got time to throw this type of training into their training programs  before every technical tactical session.

From a deceleration training perspective, I do think we do need some interventions looking at enforced stopping as a fast eccentric velocity training method, but also as a strategy to reinforce these optimal mechanics. If we want our athletes to move well, we need to practice the skill of decelerating and change of direction in pre-planned environments, but we can get onto later if you want.”

”@Alastair:  I think you emphasized a great deal that we really believe that the fast eccentric loading component of specific horizontal decelerations in the field is a really key and potentially potent stimulus. And I think we can talk about the, the gym based strategies, which obviously should work in harmony with the field based athletic development strategies.

So I think you can’t just decide, right, I’m going to focus on all these eccentric training methods in the gym, and that will create super robust resilient athletes. I think you also need to make sure that they are specifically applying all these elements in field based drills. We’ve got a library of different drill examples that we can provide obviously targeting in multiple planes as well, because we’re not just decelerating in the sagittal plane, change of direction maneuvers occur in the sagittal plane, the frontal plane and the transverse plane.

You’ve got this point where it’s almost a harmony of the gym based programming and the field based programming to get the adaptations that you want. Chris Bellon talks about using the short to long approach of acceleration development with the pioneer of that is being Charlie Francis, but talking about seamless sequential integration, whereby we are developing shorter acceleration distances first and foremost in the training cycle, and working a lot alongside that or the gym based methods that actually provide the foundation for the subsequent phase.

So as an athlete is then starting to be exposed to greater acceleration distances, they have the prerequisite physical strength and power qualities to almost harness that to optimum effect. And I think you can see how that would theoretically apply to horizontal deceleration training. So if we were to develop the foundational eccentric strength qualities alongside the pitch based stuff which might be at this point a bit more of a technical focus, making sure that we’re getting the right positions in both the sagittal and frontal plane. So we start with methods such as flywheel training or tempo eccentric training, but then developing those foundational eccentric strength qualities for the subsequent phase to which then you might actually open up the distances.

We use deceleration runways a lot, which is where you can almost increase the drill distance or the approach velocity before actually making a more intense, horizontal deceleration. And by having the prerequisite eccentric strength qualities that you’ve developed in the previous phase, you should be in a better position to tolerate the deceleration demands there. So I think it’s always about using both gym-based and field-based athletic development exercises to create these athletes or to promote these characteristics that we want to see from both performance and injury risk perspective.”

”@Tom: Sorry Alistair, just one point. I suppose it comes down to your point about the monitoring. Like we said before, we can easily integrate these kind of field-based runways and decelerations into our field-based training. We don’t know too much about the optimal dosages. So we encourage a conservative approach, with careful periodisation. I probably would say maybe only theoretically maybe 100 to 200 metres of enforced stopping probably only that’s needed because we need to be monitoring the technical tactical base sessions as well. We don’t want to overexpose athletes, but I think we certainly need more research in that area about the optimal dosages and whether that differentiates between athletes, whether they’ve got high levels of physical capacity. I’d imagine athletes with great physical capacities are able to tolerate greater dosages of this enforced deceleration training, but a kind of a careful conservative approach is what we’d recommend.

But if you’re not monitoring, you’re just guessing, so that’s why we would come back to if you’re at least getting some monitoring of the frequency and potential deceleration distances, in addition to whether you are prescribing five or 10 metre decelerations, I think that’s a really big thing to think about.

I would also just say going back onto what we know about horizontal decelerations and the unique, physiological and biomechanical characteristics that might separate them from other potential multidirectional speed elements that you’ll be exposing your athletes to. So almost looking at it from a macroscopic perspective and going right, what training sessions are we carrying out this week, the next week, over six weeks and going, right?

Can we sequence these in different ways? Because we know that the recovery timelines of these more biomechanically focused elements with eccentric loading might be quite different to what an acceleration focused session might be.  So almost looking at it over a six week cycle and actually sequencing your accelerations, your high speed running, which are maybe more of a concentric focus with less muscle damage than a horizontal deceleration would impart. And actually making sure that you’re sequencing them differently rather than just going right, I’m going to deload on week five.  You actually might want to look into it and go, I’m going to deload these accelerations and high speed running in week four, and then pick it back up in week six, and actually you might want to give a bit more time for that adaptation to happen with the horizontal decelerations. In that way we can actually harmonise and sequence different variables at different times.  You might be deloading and not targeting a specific multi-directional speed quality in one week but it doesn’t mean that you can’t target another element.”

Top 5 Take Away Points:

Science of Multi-Directional Speed