Hi guys! In this video, I'm going to talk about isometric contractions
and how you can use them in rehab and why they are so useful. So, we're going to look
at what they are, why we use them in rehab, what changes they bring about in muscles and tendons,
and then also how you can adapt them to get the best out of it, because you can't just do the same
thing the whole time; you won't go grow stronger from that. So, for those of you who don't know me,
my name is Maryke. I'm one of the physiotherapists from sports-injury-physio.com,
where you can get online physiotherapy assessment as well as treatment for your
injuries. Have a look at the description of this video if you want a link to our website.
Good! So, what's an isometric contraction? We have three types of muscle contractions.
If we take my biceps muscle, that runs from there to there, as an example: If I lift something up,
the muscle is contracting and bringing the arm up, and it's shortening as it contracts.
So, that's a concentric contraction. Now, if I lower it down, the muscle's still contracting,
otherwise my arm would just fall, but can you see that it's now lengthening as it contracts;
so, that's an eccentric contraction. But, if I just wanted to show you my guns, and I
tense it like that: muscle’s contracting, but I'm not getting any movement – lengthening or
shortening of the muscle – that is an isometric contraction. Now, you can do them in quite a few
different ways, and you can do them for all the muscles in the body – and we'll discuss
that in a minute – but why would you want to use that type of contraction for rehab?
So firstly, it's a really nice, controlled exercise usually to do. So, especially if you have
an injury that's quite sensitive, you can really make it that it's a stable exercise, and you can
absolutely control how much load goes through that muscle or the tendon or whatever is injured.
Second, it is possible to increase the load on it. So remember, when we do strength training,
when you're strong enough to handle something, you've got to increase the load a little bit
to keep on growing stronger. If you just stay at the same level, you won't make strength gains. And
the interesting thing about isometric contractions is, you can actually recruit more of the muscle
than if you just go on what you can physically lift. So for instance,
if I wanted to do bicep curls. Say for instance I'll be able … The max weight that I can lift
is 15 kilos with one arm, doing a curl, but if I'm doing an isometric contraction, that
I'm not actually lifting it, I'm just contracting against something that stops my arm from moving,
I can recruit much more and its forces that's higher than what I can physically lift. So,
you can actually get really good strength adaptations from that.
But it comes with a warning for rehab, and I will discuss that in a minute.
Then, you can apply the contraction in exactly the part of the range where the
muscle is the weakest and needs it the most. So for instance, if we think of this action,
there's often ... you'll find that the muscle is quite strong here and strong there, but then
maybe out there, it's not as strong as it should be. So, you can then start
with isometric contractions just in that range to strengthen specifically that part of the muscle,
or ... of the range where the muscle isn't that strong. Whereas when you're doing concentric and
eccentric, you often don't really … you can't really target that specific part so well. And
then lastly, it can also have an analgesic effect, which means it can bring pain down. So, if you do
isometrics before you do an exercise session, you can actually find, if you've got an injury, you're
much more comfortable when you do that exercise session. I use it a lot as well as part of
my warm-up session before I go for a walk or a run, because it just frees everything up and
gets things going without actually making me tired. Okay, so those are the reasons
why we would use them in rehab. Now, what do they actually do? So, they have been shown
through research that they can bulk up your muscles. So, they can give you muscle bulk.
Don't worry, you're not going to get massive muscles from doing them, but you do get muscle
gains. And, depending on how hard you train them, you can get significant muscle bulking from that.
Then, you can also … For tendons, they have been shown to improve the structure and the health of
the tendons. So, they increase the stiffness of tendons. And remember, when we talk about muscles,
we always want flexible and strong muscles, but for tendons – a tendon that's injured is soft;
a healthy tendon is actually more inflexible and stiffer, because it needs to return energy. And
what isometrics have been shown specifically for tendons is, it helps to improve that
stiffness and the tendon health itself. Then also, it helps to develop the nervous system.
And when you have an injury, often the nerves go to sleep a little bit; we talk about neural
inhibition. So, it can activate them again it, can wake them up. And then, depending on the
type of contraction you do and the intent of the contraction, you can even train the
muscles to contract – to be prepared for something specific. So for instance ... give you an example:
If we think of normal strength training, you'd have slow, heavy resistance to just
get some strength through it. Then you'll have plyometric training, which is quick, explosive
type of contractions that prepare you for quick movements in sport. Now, with isometrics,
remember you're not getting any movement, but if you do a slow take-up of that contraction,
it's a similar way that you're developing the nervous system as for slow, heavy resistance.
If however, you're doing fast, that you get to that contraction quickly, and a hard contraction,
they've shown that the nervous system adapts in the same way as it does to … What's the word now?
Power training type exercises. Then, there's also some research on performance, but this
video is more about rehab, so I'm going to stay to those three. For maximum muscle bulk gains,
they've shown that if you do the isometrics in the outer range, or where the muscle is lengthened,
so for the biceps, if I'm in this range of the motion, you can see that the muscle is
in a shortened range; out there, it's going to be in a lengthened range. And if you want
the most muscle bulk to develop, training it in the outer range is the better place to get that;
and also high volume of training and holding it for longer periods of time
will give you better adaptations with regards to that. Tor tendon strength, again, it's in the
outer ranges that you're gonna get the most gains. And also, it is the longer contractions; short
contractions with quite a lot of rest in between, even if it's the same volume in total, do not
bring about the same tendon stiffness as holding it in a contraction for a longer period of time.
So, I'll talk about how you're going to apply this in your rehab in a minute, because you can't just
jump in with that. Okay, so that's basically those bits. So, let's talk about how do you actually
then incorporate this in rehabilitation. Now, I'm going to demonstrate this for the high hamstring,
or for hamstrings, because it's the easiest thing to demo to you. So, when we start with rehab,
we always want to find a position that we can contract the muscles in that does not cause pain,
but you want to go for the most challenging one that doesn't cause pain.
So, if you do the easy version, it's not painful, test one up; if it's not painful, test one up.
Oh, now it hurts, come one back. So, you don't start in the easy version if you don't have to;
you can start a few ahead, but it should not be painful. So, you should start at
the correct level for you. Now, if you start ... So, let's think about the variables here:
We're going to think about the range of motion or the length that the hamstring tendon is at
when you work it, because that's one way that we can make the exercise more difficult.
We're going to think about the length of time you hold the contraction for, because
that's another way that we can overload it. And then lastly, we're also going to think about
how we can we actually increase the intensity by increasing more weight through that,
so there's more muscle fibres that need to be activated to hold that position. So, that's
going to be the three variables we're going to play with today. So, let's look at the hamstring.
So, the hamstrings are the group of muscles that run at the back of the thigh. They
attach to the sit bone, roughly, and come and attach around the knee as well. So,
to do an isometric contraction of them, this is the simplest: a glute bridge. Now, you can see,
if you can imagine the muscle running down the back there, it's in a shortened form. So, we're
getting some strength gains, but it's not maximal yet. But if this is where you've got to start,
this is where you've got to start, and it's right for your tendon and your hamstring at that point,
because it's hard enough. So usually, if this is the level, you want to start with: 10 second hold,
rest about 10 seconds, repeat that quite a few times. As that gets easier, you start increasing
the hold time to eventually get to 30 or 40 seconds, but fewer repetitions. So typically,
if you can do 30 seconds – four times or five times holds with rest in between,
then I would say it's time to move on to the next level at least. And how do I make this more
difficult? You move your feet out, because now, can you see the hamstring is at a more lengthened
… is longer when it's gotta work here? So, it's harder work for the hamstrings. And then you
can make it harder still by sliding the legs even further out, that it's really lengthened,
and at this point, I usually like getting people to place their feet on something high,
because if you do it there, then you'll really feel the hamstrings working, because can you see,
my knees are nearly straight, and the hamstring is in a really lengthened position.
But now, we've increased the whole time, we've increased the length,
and now that's too easy. So, where do we go from here? Well, we increase the load. So, you can
either then put a weight over there to make it heavier, or we just switch to single-leg ones.
But then you start with easier versions again, and just see if you can hold that, and again
you're playing with how long you're holding it for, the range of motion you can hold it in for.
So, you can literally do that for every single muscle in the body, that you always start with the
easier versions. Remember, you're not allowed to have pain while you're doing it; a little bit of
discomfort is okay, but it shouldn't be classed as pain or cause you more pain after you've done it.
Start with short holds, build up to longer holds; if you can do long holds in that position,
it's time to make it more difficult. So, you either have to increase the range you're working
through or increase the load by putting weights or something on there. Great! Let me know if you've
got any questions. And remember, if you need more help with an injury, you're welcome to consult one
of us via video call – the link to the website is in the description of this video. Take care!