The perspective that the body is an interconnected unit that displays regional interdependence is a valuable one. That different parts interact in different ways during different activities and influence ROM (range of movement) in other areas of the movement chain should seem a fairly easy link to make when looking at the whole body during different context dependent movements. We often eschew the value of the integrated system in favour of the isolated joint/muscle model.
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I had an interesting case this week involving a water polo player who was experiencing shoulder pain when throwing. This pain was only occurring however when he put maximal effort into the throw. Now I do not get to see many water polo players so this was a challenge. I decided to put aside the fact that ground reaction forces would be different as well as having two different resistances on the upper and lower parts of the body (air and water friction) as this would present even more challenges to the assessment!
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So its been a while since I last wrote a blog. Been pretty busy moving house and working hard so had very little time.

This blog is all about the movements that we give our patients/clients to perform and how we may need to pay closer attention to how they do it for maximum impact on the system.

One of the things we look at heavily during the Cor-Kinetic Mentorship program is the reaction created by the movement we perform. Just because we believe that a movement we prescribe will enhance our clients movement does not mean that this movement will give us the reaction we desire.

Understanding the authentic biomechanical movement that we need in the first place is only one half of the battle. If it was as simple as that then very few people would be in pain. How much of that movement does some one tolerate is the question, and to find the answer we need to look at their movement threshold.

If we have too large a movement into an area that lacks the required movement then you will get a compensatory movement from the body. It is as simple as that. The response you thought you would get will not occur. In fact it could be this compensation that is causing the pain you are trying to eliminate. This is why it can be hard prescribing corrective exercises. You don't know if you are feeding the compensation beast or correcting a movement! The more we go towards end range the more the variability of the response becomes. As the demand/stress increases so does the bodies need to find an alternative pathway.

Along with patient adherence this has always been the problem with corrective exercise prescription for the client to go away and perform on their own. This is where the science of the body meets the art of the practitioner. As the body is not a linear system and does not follow a set pathway every time it moves we have to be able to interpret and control movement at the moment it occurs and be able to adapt movement for a favorable reaction. Not always and easy thing to do but hugely powerful once you can start to implement this thought process.

To guarantee that the reaction we need to find the threshold of success. This is a concept borrowed from the great Dr David Tiberio of the Gray institute. The threshold is the point that the movement can still have a positive reaction the vast majority of the time and will remain pain-free. The more we go over the threshold and suddenly the movement becomes unsuccessful as the body tries to find another pathway or creates pain to reduce the sub optimal movement created. The key is feed the body a little more demand each time. Inching over the threshold bit by bit until we have a consistent positive reaction. Understanding the range, angle and speed of the movement can help you increase and decrease the variables to be able to have full control over the patients/clients success and being able to increase it. It maybe that the threshold we have in terms of range will decrease the faster we get. This maybe of great importance for a sports player who has to increase their movement speed.

An example of this process would be a lunge for increased pronation of the foot. If we were stepping with the right foot then we would want to step across to the left half of an imaginary semi-circle in front of me (somewhere around 45 degrees left would be good!). If the body cannot get this movement under increased force then it will try to decrease the impact on the system. A couple of ways it may do this is simply to roll to the outside of the foot or adduct the foot (turn it in). In these ways it reduces the demand on the structures that would get eccentrically stressed during pronation (Tri plane-dorsi flex, abduction, eversion) . We need to be able to find the threshold or angle that decreases these compensatory reactions and progress slowly until we have the angle and reaction we need/desire. A better angle to start at maybe 10 degrees gaining a consistent reaction before moving to 20 and so on and so on. When the reaction becomes less consistent we can come back to success and start inching over the threshold degree by degree. It may sound time-consuming but is actually a quick process when you learn to control it!

In this way we can regress and progress the movement to create continued success. The more the body feels and interprets this success the more we can feed the neurological system to allow the continued success to become a predominant pathway of movement. It is not always the movement we give but the way in which we give the movement!

As the great Gary Gray says "The test is an exercise and exercise is a test". In this way we can interpret the success of any movement we perform and constantly evaluate the success of the individual we are training/assessing/treating.

A purely academic/biomechanical approach to functional movement may lead us just to understand what movement is required and give as much as possible. This is something I have seen many times with a fairly low-level of success. The variability in the creation of the desired movement is high. At Cor-Kinetic we don't see that as the answer. In fact in this scenario more can actually lead to less, the path to success is in the way that you do it. Our tag line is "Evolving movement" both our students understanding of movement and our clients movement potential.

If you have ever looked at the biomechanics of the backswing in golf it becomes obvious that being ‘on plane’ is a perfect functional combination of the three planes of movement available to the body, sagittal, transverse and frontal. My recent foray into the world of video analysis with golf has inspired my post!!

This also kind of ties in with my friend Dave Westerman’s recent video explanation of biomechanics involved during the golf backswing.

When we may start to see problems is when the body does not have the capacity to move in the plane required. A strategy we may see is the body obtaining more movement in the plane it can get to compensate for movement in the plane that it can’t get.

The required motions in the backswing at the hip are extension (in a flexed position), ADDuction and internal rotation. The aim in the backswing is to not shift the Centre of mass to far to the right for a right handed golfer. The larger shift in mass and translation of the pelvis comes during ball striking and follow through. This acceleration of mass creates the force required to propel the ball.

A common swing fault can occur when instead of using the transverse plane to create relative internal rotation at the hip, we instead utilize frontal plane translation. This pushes our centre of mass over to the right for a right handed golfer.

What we now see is an inability to sequence correct motions in the swing. The shift in weight cannot be reversed in time so that the hips can create a proximal acceleration to provide additional load to the core, chest and shoulder. By the time the hands have started the down swing the hips are still lagging behind, unable to cover the range in the timeframe available. This frontal plane translation could also compensate for the ability to get opposite side lateral flexion. The shift in mass through hip motion creating more or the illusion of more lateral flexion.

This change in sequence can lead to inefficient and ineffective swing mechanics and also to injury to the tissue that relies on this correct sequencing. The lack of mass in the F=MA equation will also severely reduce power.

This is very similar to what happens during overpronation at the foot. The large motion and increased range into pronation means that the body is unable to reverse this motion into supination by the time the swing phase of gait is initiated. This leads to a back foot pronation and reduced movement in the rest of the kinetic chain.

As with all sport golf, relies on the sequencing of movements to accelerate our mass at the correct time.  Our ability to understand our client’s function and our clients ability to perform their function is vital to our success.

Check out Cor-Kinetic for loads more functional info and course dates.

Overpronation is one of the most frequently used terms I hear in fitness. This is from both trainers and clients. The plethora of pronation control shoes has plucked the word from the world of anatomy and physiology and biomechanics into everyday terminology.

Although the word is widely used it is not widely understood. Overpronation can happen in many ways and for multiple reasons but is generally used as a generic term and no more attention is paid to it.

Lets first define pronation. It is the triplane action of dorsiflexion, eversion and abduction at the rearfoot.  These joint motions are relative to the bone motion of the talus which is the primary moving bone in a closed chain scenario. This rearfoot motion will also create relative forefoot dorsiflexion, inversion and abduction. The forefoot can have quite an impact on rearfoot pronation that we will talk about later in the blog!

Now lets look at the different ways in which we can overpronate.

1. Range-I think this is the "classic" definition of overpronation. The amount of distance that the joint goes through. Obviously far too much range places stress on the joint and muscles all through the kinetic chain of the lower limb. The associated tissues have to work hard to control the excess range. Common problems that can arise are posterior tibialis syndromes, Achilles problems and ITB problems.

2. Rate-Along with range goes the rate or speed/acceleration of pronation. The larger the range, the more distance to accelerate into. This again causes problems for the muscles/tissues that have to decelerate this increased acceleration.

3.Sequence-This is the most overlooked element of overpronation. Pronation should occur at initial heel strike and be followed by supination. If the range and rate are excessive then the foot is unable to reverse the motion in time to go into supination. This means that someone may pronate through midstance and also through the propulsive phase of gait. If any of the motions associated with supination are restricted it may also lead to a return to pronation late in the gait sequence.This can also be because of the instability created by the pathomechanics of different foot types. This can lead to plantar fascia problems and HAV bunions as the foot remains in its unlocked mobile state rather than becoming the rigid propulsive unit that the supination process creates.

The question most often overlooked when it comes to pronation problems is WHY??           A good knowledge of foot dysfunction is required to really answer this question. The most overlooked area in my opinion that causes pronation problems is ontogenic (developmental) forefoot positioning relative to the rearfoot. However I am also really interested in the spatial location of the STJ (subtalar joint) axis. The medial  deviation of the STJ will increase the moment arm of GRF (ground reaction forces) associated with pronation and decrease the moment arm of the supinatory muscles. It will also increase the area of the foot laterally to the STJ that  cause pronation to happen when force is applied. The lateral deviation will do the opposite with more internal muscular supinatory force and decreased GRF pronatory force occurring and increased medial area of the foot that will cause supination.

Anyway, back to the forefoot!! An inverted or varused forefoot position will be compensated for at the rearfoot by excess pronation. Another scenario is that the foot is able to get into supination but the extra instability of the varused forefoot causes a pronation response to get the forefoot on the ground and create stability. This would happen late and out of sequence in the gait cycle. This means that just controlling the longitudinal arch as many pronation control shoes do, does not gain quite the control anticipated.

Many times I also see short or half foot orthotics. These orthoses have arch control but do not provide stability at the forefoot. This is done by bringing the ground up to the foot, to stop the foot trying to search out the ground. Without the forefoot control I see the foot unable to pronate to compensate because of the arch control, instead using the transverse plane to rotate the foot and tip onto the forefoot. This maybe a reason behind a medial heel whip!! A similar thing can happen when the STJ axis height is high and favours transverse plane motion over frontal. The STJ axis height should be around 42 degrees from the transverse plane, slightly favouring frontal plane motion.

I realise this a bit of a big post, but is also a really big subject. Much more complicated than many give it credit for, so thanks for reading. Until next time....

Ben Cormack