Biomechanics Q & A: Post your questions here

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Biomechanics is the study of the human body and how it moves in mechanical terms. The science is divided into two areas of study: extrinsic and intrinsic Biomechanics.

Intrinsic Biomechanics is the study of how the body is able to perform any movement and relates to your mechanical make-up; any anomalies with your Biomechanics can have a profound effect on how you perform extrinsic tasks (like lifting weights) and the efficiency with which they are performed. In addition, intrinsic factors can have a major impact on the potential risk of injury for you, whether you are a professional athlete, a keen recreational sports enthusiast or simply working on a production line.
 
Your biomechanics will affect how you perform every exercise you do.  So if you have a leg length discrepancy, overactive muscles, tight nerves, muscle imbalances or a twisted pelvis they will not only affect any injuries you have, but also your ability to lift heavy weights if you are a power lifter, or your muscle symmetry if you are a bodybuilder.  If you don’t understand your biomechanics, you won’t be able to train to your maximum without getting injured and so you’ll win less competitions.
 
A company called Intelligent Training Systems (ITS) has developed a way of measuring these problems and can prescribe subtle but powerful exercises to help rectify them.  ITS qualify people as Personal Trainers and then provide a career progression and train them as Biomechanics Coaches, a new and exciting qualification for enthusiastic fitness trainers who want more from their jobs.
 
Biomechanics, and how it affects not only your athletic performance, but also your day to day life, is a very new area and unknown to most people and it can affect you in profound ways.  An example of this is how shoulder pain can actually be caused by a problem at the pelvis through something called myofascial slings.  These are chains of muscles that link the body beyond the simple biceps and pecs, there is much more to it than that!
 
Also find out why there can be very good reasons why most people shouldn’t be doing core exercises!
 
We would love to hear questions from people, for example about how the body works as a system, how to perform exercises based on your particular problems, how to analyse how to perform exercises correctly, how biomechanics can be used to increase performance!

www.intelligenttrainingsystems.com

Ok so let me pose a question....
Why is it better to do full range lateral raises rather than to 90 degrees??
(Full range being from sides, externally rotating the arms from 45-80 degrees so that by 90 degrees the palms face upwards and come together over head)

I'll have a think tommorow and see what i can come up with, i'll fire a few back your way too.

Right, biomech hat on time, been a while since i had a conversation about some of this stuff so handy to dust it off!

I can't come up with one outright conclusion, although heres a few thoughts i've had on it.

Full range may be better because;

• Supraspinatus is supposedly the primary abductor for the first 15 º of movement, meaning you've only got ~75º to play with going to 90º as far as lateral delt activation goes.
  
• Larger RoM = Larger IEMG readings likely to occur, potentially more 'overall' muscle activation if you're generating a longer TUT. Moment of Inertia theoretically would be bigger too if you're increasing the distance resistance is applied over.

Full range may be worse because

• Greater IEMG readings may be at the expense of peak amplitudes, i.e using a much lighter weight. Will you break down fibres more efficiently by going 'heavy' to 90º or lighter with full range? Who knows.
• More scapulothoracic muscle activation with full range movements. Going past 90º will see you bring into play the upper/lower traps and serratus anterior to stabilise the scapula. Although you'll see some upward scapula rotation to 90º, you'll see more compensation at the shoulder joint behond this point (rule of thumb is 1:2 - 1º of scapula upward rotation per 2º of humeral abduction, AKA scapulohumeral rhythm).
  
• So if muscle isolation is your goal, then full range may give you a tad more overall lateral delt activation, but the magnitude may be lower when you start bringing the scapular muscles into play.

Whats your take on it Rachel? Keen to see what your reasoning is

interesting answer mate, some thought gone into it, just the discussion they were looking for!

Whats your profession? is in in the fitness industry?

Finished my undergrad in Sport & Exercise Science (final year dissertation in Biomechanics) in the summer and started my MSc in Physiotherapy a couple of weeks ago.

The physics/biomech side of things is pretty much interlinked between the courses, although my thought process at the moment is still more geared towards performance rather than rehabilitation. Absolutely fascinating area for me, so i'll try and think up a few obscure training questions once Rachel pops back in here

Below is a Q & A copied from my personal journal to here, from where I have deleted it

swift

Hello Rachfit.
 
I have a couple of questions...
 
When training the lat's do rowing movements offer a better contraction than movements through the vertical plane of movement such as pulldowns/chins. I believe rows are more beneficial than chinning type movements but would like to hear your thoughts on this as my thinking is that your shoulders are in a much stronger position operating in a horizontal plane.
 
Which type of horizontal plane movement is the best for lat development, overhand or underhand pulldown/chin type movements? time and time again people preach that overhand gives best lat width but im not sure, as i think the bicep is in a stronger position biomechanically when doing a palms facing you type pulldown movement and so a greater load can be put through the lat. 
 
anythoughts on this would be appreciated

Rachfit


Hi there and thank you for the questions!
 
There are several ways of looking at this...........in a row movement there are a limited number of muscles that will extend your shoulder.  Mainly they are the lats, teres major and posterior deltoid.  So lats are one of 3 muscles.  In the lat pulldown movement there are more muscles to assist the movement; late, teres major, posterior deltoid and pec major.  So in this comparison, the load is shared by more muscles in the lat pulldown so the row provides the lat with more of a challenge.  On the other hand the lat (and its assistants) are required to work through a larger range of movement in the lat pulldown, so their force of contraction is potentially greater.
 
The hand position in a lat pulldown or chin movement is an interesting one too..........on one hand in the underhand grip (where the palms face you) the arms are closer together and so the lat is taken through a larger range, which is good, but the bicep is in a mechanically advantageous position so it can actually take the load off the lat, which is not good for lat development.  On the other hand an over hand grip (which is usually wider) can be argued to hit the lat more as the bicep is in a poor mechanical position and so the lat needs to work harder to perform the movement.  Another key factor to consider is the angle that the hand grip promotes.  The grip does not actually change the muscle length directly as the muscle does not attach anywhere near the forearm, which is where the grip position comes from.  But what it does do is alter the angle of the movement.  In other words an over grip causes the movement to be more of an adduction of the shoulder whereas an undergrip causes the shoulder to come down in more of an extension movement.  The latter feels like a stronger movement for some of the reasons listed above but also because the shoulder joint is in a more natural position so you can generate more force.
 
Generally it is believed that a wide grip produces a wide lat, and row movement produces a thick/deep lat, but there is much to be said for genetics influencing this.  Look at the Bertil Fox in the old days, he didn’t have access to  a lat machine until he went to the USA, and his was one of the widest lat spreads ever seen!!
 
So the moral of the storey is that there is no ‘one size fits all’ and its important to vary the exercises to provide as much stimulation to the lat as possible to create the best opportunity for growth, one exercise may be great for your friend and another may be more suited to your biomechanical make-up, but whatever you do............... train heavy!
 
Hope this helps

Thanks James.

I get the feeling i'll be spending a lot of time in this thread!

Ak_88


Finished my undergrad in Sport & Exercise Science (final year dissertation in Biomechanics) in the summer and started my MSc in Physiotherapy a couple of weeks ago.

The physics/biomech side of things is pretty much interlinked between the courses, although my thought process at the moment is still more geared towards performance rather than rehabilitation. Absolutely fascinating area for me, so i'll try and think up a few obscure training questions once Rachel pops back in here

 

nice one mate!  they will love it, all their stuff leads to ultimate performance

Ak_88


Right, biomech hat on time, been a while since i had a conversation about some of this stuff so handy to dust it off!

I can't come up with one outright conclusion, although heres a few thoughts i've had on it.

Full range may be better because;

• Supraspinatus is supposedly the primary abductor for the first 15 º of movement, meaning you've only got ~75º to play with going to 90º as far as lateral delt activation goes. THATS WHAT MARTIN HAINES WAS TAUGHT A MILLION YEARS AGO, (HE IS MY PHYSIO COLLEAGUE, MENTOR, THE GUY WHO DID ALL OF THE RESEARCH OVER THE LAST 25 YEARS ON BIOMECHANICS AND ITS COMPANY DIRECTOR) NOW ITS RECOGNISED AS MERELY INITIATING THE MOVEMENT, IN OTHER WORDS DEPRESSING THE HEAD OF HUMERUS TO ALLOW BETTER BIOMECHANICAL LEVERAGE FOR DELTOID
• Larger RoM = Larger IEMG readings likely to occur, potentially more 'overall' muscle activation if you're generating a longer TUT. Moment of Inertia theoretically would be bigger too if you're increasing the distance resistance is applied over.

Full range may be worse because

• Greater IEMG readings may be at the expense of peak amplitudes, i.e using a much lighter weight. Will you break down fibres more efficiently by going 'heavy' to 90º or lighter with full range? Who knows. INDEED
• More scapulothoracic muscle activation with full range movements. Going past 90º will see you bring into play the upper/lower traps and serratus anterior to stabilise the scapula. Although you'll see some upward scapula rotation to 90º, you'll see more compensation at the shoulder joint behond this point (rule of thumb is 1:2 - 1º of scapula upward rotation per 2º of humeral abduction, AKA scapulohumeral rhythm).
  CORRECT, WE DO ACTUALLY TEACH THIS ON THE COURSES. THAT HOWEVER IS THE ADVANTAGE....IF SHOULDER ABDUCTION IS INTENDED TO MOVE THE SHOULDER JOINT, THE A/C JOINT, THE SCAPULA/RIB JOINTS THEN WHY STOP IT MOVING THE WAY IT WAS INTENDED BY DOING HALF A MOVEMENT?  ITS LIKE DOING HALF A LEG CURL OR HALF A BACK EXTENSION.  PLUS IF WE’RE NOT TRAINING THE SERRATUS AND UPPER TRAPS WITH SUPRASPINATUS AND DELTOID WE’RE CHANGING THE NORMAL SCAPULO-HUMERAL RHYTHM, THEREBY RENDERING THE SHOULDER MORE VULNERBALE TO INJURY.  MUSCLES ARE DESIGNED TO WORK IN CHAINS IN A SYNERGISTIC FASHION.  UNDERSTANDABLY BODYBUILDERS NEED TO ISOLATE AND RIGHTLY SO, HOWEVER BY UNDERSTANDING THE CORRECT MOVEMENT PATTERNS OF JOINTS/MUSCLES WILL HELP MITIGATE THE RISK OF INJURY AND HELP RESTORE CORRECT FUNCTION THERBY ALLOWING CONTINUED TRAINING.

BY THE SAME ARGUMENT WOULD YOU WORK THE SHOULDER TO JUST 15 DEREES OF ABDUTION TO WORK SUPRSPINATUS SO IT PUMPS UP THE UPPER TRAPS AND LEVATOR SCAP?  PROBABLY NOT AS IT WOULD LIKELY WRECK THE SHOULDER.

So if muscle isolation is your goal, then full range may give you a tad more overall lateral delt activation, but the magnitude may be lower when you start bringing the scapular muscles into play. IF MUSCLE STRENGTH AND SIZE IS THE GOAL THEN THE FULL FANCY FUNCTIONAL MOVEMENT EXERCISES LIKE ‘WOODCHOP’ ETC WILL NOT WORK BECAUSE ITS NOT ISOLATED ENOUGH, HOWEVER DOING LATERAL RAISES TO THE TOP IS ISOLATED ENOUGH TO BE USED IN BODYBUDLING TERMS, YET FUNCTIONAL ENOUGH TO WORK THE JOINT HOW IT WAS DESIGNED TO BE USED. Whats your take on it Rachel? Keen to see what your reasoning is

Please check out above.
Great stuff!!
 

Interesting logic - good to see another perspective on things.

I suppose from a performance and functional point of view it does make sense to move a joint through it's full range of motion - the only BB'ing examples that don't really adhere to this (in my mind) would be lateral/front raises. I don't suppose you have anything evidence-based regarding a 'normal' lateral raise and a full range one? Would be interesting to see how the data compared!

One for you then Rachel - what do you think the best method of optimising form for the big three lifts (Bench, Squat and Deadlift) is for individuals - with regards to stance, grip width, and so on?

For arguments sake lets use 2 people - 1 with long limbs, 1 with short limbs, assuming they have no prior issues r/e muscle balance, tightness, etc.

It's also quite nice to read all this and understand it rather than having 'jargon' thrown about that soon renders the debate void to those of us reading late at night after a 14hr day and still at work (I use the word 'work' loosely obviously) 

ooooh, and if you can give the answer to long limbed bench (and other variables of) press success I'll love you forever

I can't tell if you're being serious or if all my bollocks ramblings have gone over your head LOL.

LOL, no genuine - altho you did go off on one a little bit
 
It's something I should keep myself more read up on but simply never do

Ak_88


Interesting logic - good to see another perspective on things.

I suppose from a performance and functional point of view it does make sense to move a joint through it's full range of motion - the only BB'ing examples that don't really adhere to this (in my mind) would be lateral/front raises. I don't suppose you have anything evidence-based regarding a 'normal' lateral raise and a full range one? Would be interesting to see how the data compared!

One for you then Rachel - what do you think the best method of optimising form for the big three lifts (Bench, Squat and Deadlift) is for individuals - with regards to stance, grip width, and so on?

For arguments sake lets use 2 people - 1 with long limbs, 1 with short limbs, assuming they have no prior issues r/e muscle balance, tightness, etc.

We dont as far as I know but I will ask Martin once he returns from trekking the Himalayas, end of the month. He is the one who did all of the years of research for our Biomechanics courses. It would be very interesting to see some research and we are hoping to get to the point where we can start doing more in our own lab! However we are not there yet :)
 
With regard to form on the 3 big lifts it is a difficult one to answer for a few reasons.
Everyone is so different in shape and size and even if we were specific to the limb length it would depend on what the individual is trying to achieve and there own genetic make up including biomechanics. This is all still important even if well stacked up through pelvis, spine, nerves and joints.
In saying this I believe for a bodybuilder it is prudent to train in a variety of hand positions, stances and grips for overall strength and the position at which they feel the strongest is where they are likely to lift heaviest.
 
What are your thoughts?
 

Can I just point out here that the Biomechanics we teach is not the usual stuff delivered and talked about. More often than not Biomechanics courses are specific to the extrinsic form (the ability to analyse the most mechnically efficient way to perform and exercise) while we are specialists of the intrinsics (the ability to measure how the body is stacked up on the inside and how this impacts on the extrinsic and the potential for injury to occur).

We are the only people in the world delivering a Biomechanics coaching qualification and this injury prevention programme.

I welcome questions from anyone with any interest in reducing aches, pains, want to move more freely and with regards to the way intrinsic biomechanics can impact upon bodybuilding or exercise of any kind...whether you know about Biomechanics or not :)

Hey

i have 'interest in reducing aches, pains..."!! I've had lower back soreness/stiffness for a very long time. I tend to find myself arching [while stood or sat down] quite often - more as a habit/reaction than for alleviation. It is generally much worse in the morning and terrible if i have to sit down for a long period of time.

I have been stretching twice a day [when possible] for about 3 months now which helps, although it seems as if its just short term relief - the few hours after stretching. I tend to stretch lower body muslces [hams, gluts, quads, lower back, hip flex] daily and reserve upper body for post-workout.

In terms of training, i avoid putting too much stress on my back -either by loading or exercises like heavy bent over rows. In the past i've made good progress in Squats/Deads but find, over time, they don't do me any favours. I tend to stick to unilateral leg exercises. I tend to add 'core' work at the end of my workout, usually a 3 exercise circuit. - things like birddogs, front/side planks, ex.ball crunch, back extension...

I'm not sure if this is the kind of issue you were after?! but i guess it is an injury question, although not one that seems to have occured as a result of a particular exercise.

Thanks all the same

blanka


Hey

i have 'interest in reducing aches, pains..."!! I've had lower back soreness/stiffness for a very long time. I tend to find myself arching [while stood or sat down] quite often - more as a habit/reaction than for alleviation. It is generally much worse in the morning and terrible if i have to sit down for a long period of time.

I have been stretching twice a day [when possible] for about 3 months now which helps, although it seems as if its just short term relief - the few hours after stretching. I tend to stretch lower body muslces [hams, gluts, quads, lower back, hip flex] daily and reserve upper body for post-workout.

In terms of training, i avoid putting too much stress on my back -either by loading or exercises like heavy bent over rows. In the past i've made good progress in Squats/Deads but find, over time, they don't do me any favours. I tend to stick to unilateral leg exercises. I tend to add 'core' work at the end of my workout, usually a 3 exercise circuit. - things like birddogs, front/side planks, ex.ball crunch, back extension...

I'm not sure if this is the kind of issue you were after?! but i guess it is an injury question, although not one that seems to have occured as a result of a particular exercise.

Thanks all the same

Hi yep exactly this type of thing!
It is very common for 'athletes' to feel aches, pains, niggles, stiffness etc when there has been no obvious damage done.
Life is irreguar, asymetrical and thus causes Biomechanical dysfunctions that we are often completely unaware of.
Once we begin to train and move upon those dysfuctions we begin to groove out irregular patterns in our musculature. This impacts upon the kinetic chains that run through the structures of the body including the skeletal and nervous system and so result eventually in the aches, pains and eventually the injury from that weakened structure.
First of all I would strongly recommend you avoid any dynamic core work what so ever. By the way forgive my ignorance but what is a 'birddog'?
If the trunk and pelvis are not stacked correctly doing core exercises will strengthen the body in that incorrect position and so encourage injury to occur. 
Stetching is good if your muscles are tight. But what we dont know at this stage is if they are tight or in spasm. The type of spasm I am talking about is sub clinical and so not necessarily the spasm we immediately think of that causes instant pain. Sub clinical spasm needs to be released using a specific technique that releases the muscles rather than stretches them.
It is difficult for me to understand exactly what is going on with your intrinsic Biomechanics but if you found a Biomechanics coach in your area thay could certainly do a full screen and advise you or I can do my best on here by asking more questions?
 

http://weighttraining.a...isegallery/a/birddog.htm -  The Bird dog - i agree, probably one of the worst named exercises ever.

What exercises do you have in mind when you mention dynamic core exercises?

I would appreciate any advice you could give via MT, by all means, ask more questions

Thanks

blanka


http://weighttraining.about.com/od/exercisegallery/a/birddog.htm -  The Bird dog - i agree, probably one of the worst named exercises ever.

What exercises do you have in mind when you mention dynamic core exercises?

I would appreciate any advice you could give via MT, by all means, ask more questions

Thanks

Aha! The 'birddog' in the fitness industry is sometimes known as the superman. Thanks for that.
When I talk about avoiding dynamic core work I mean anything that works the core through flexion, extension or lateral flexion and extension of the spine.
Without having a robust spine, pelvis and trunk area this type of work is potentially very harmful. Even more so if used over a prolonged period of time.
A big mistake people often make (or are recommended to make) if they have a bad back or back pain is to work the core on stability balls or do hyper back extensions to attempt to put strength into that area. Theoretically that is correct IF and only IF you have great Biomechanics.
More often than not we do not and it is then that you are stabilising yourself in the wrong position and so creating a great environment for injury to occur.
If you imagine the spine can safely take a load of pressure to the value of 2,500 newtons.  Once you start doing crunches, for example, on a stability ball you are loading the spine with 3,500 newtons or pressure. The hyper back extensions load a massIve 6,000 newtons of pressure through the spine!!
So now that I have trashed your core routine we need to try and do our best to get you sorted.
It means you need to begin by releasing muscle of the hip which are often in a sub clinical spasm that we are totally unaware of. The spasm can cause leg length discrepancies, twisted pelvis and scoliosis in the spine to compensate and often we are totally unaware of this but can feel 'tightness', 'tension', 'tingling' or aches and pains caused by these imbalances.
The muscle release technique is a very subtle contraction of the muscle done at about 20% of your maximal effort. Held for just 20 seconds and done 4reps 4 sets daily. The 20% effort is important and teaches or reminds the muscle how to relax again thus releasing it. This can be instant or may take a few days (up to 6 weeks) depending on how long you have had the tension.
Exercise no. 1:
4 Sign
Sit on a hard chair, cross one ankle over opposite knee, keeping joints clear. Place hand onto inside of top knee. With NO movement press your knee into your hand, to engage your piriformis, with 20% effort for 20 seconds. Release and repeat 4 times.
 
Let me know how you get on with this.....