Shoulder motor control

Date: February 22, 2018 Author: James Categories: Latest
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I have written many time in the past on this blog about how to use various exercises to help progress shoulder strength and stability. For example here I talk about using a pushup as an exercise to help strengthen and stabilise the shoulder.

Let’s be clear, the pushup is wonderful - and I do mean that, if you want to see more writing on my love affair with the pushup as THE quintessential push-based strength training exercise (yes, I’m serious) please check out my entry on the pushup in my eBook The Foundational Movements here.

Here’s the thing though. The pushup itself is not the key rehabbing component of the exercise as discussed in that video above. What we are really gunning for is control of the scapula (shoulderblade) and the glenohumeral (GH) joint - the ball and socket part of your shoulder. This control, your ability to stabilise the scapula and GH and to guide their movement through space in a controlled and task appropriate manner, also known as motor control, is the key outcome we train. The pushup is simply a great motion context in which to practice this motor control.

Imagine these two anatomical components, the scapula and the GH joint. Let’s look at them as individual pieces for a moment. Also check out the video attached for a visual demo.

Looking from behind at rest, the scapula should be sitting in neutral to slight up rotation.  It should be not protracted too far away from the spine, and not reatracted in too close to the spine. A rule of thumb is about 4 finger widths from the spine at rest. Similarly it should not be shrugged up into an elevated position, or sitting low in a depressed position

Looking from the side the scapula should not be excessively forward tilted or winging at the inside aspect. These are common problems that associate with  slouched and forward sloping shoulders

At the GH joint, the ball that is the head of the humerus (upper arm bone) should be centralised in its socket on the scapula. In other words we want to avoid having the ball sit too far forward or backward in the socket.

The reasons why any of these positions might be less than ideally aligned can get a little complicated, but suffice it to say that  good strength and a balanced rotator cuff helps to seat the ball in the socket at the GH joint. Similarly, strength and balance between the pecs, rhomboids, traps, serratus and levator scapulae help to properly position the scapula.

The situation where poor muscular strength, balance and control of the shoulder complex lead to poor positioning of the GH and scapula is known as Multi-Directional Instability (MDI). This can lead to pain and dysfunction that impairs ability in day-to-day activity.

For a quick and dirty primer on this have a look at the video above, I discuss in a little bit of detail there and use the Essential Anatomy app to visualise the anatomy. Hopefully this goes some way to explaining the details above that translate better in image than through the written word. You can download the app for Apple, Android and Windows devices.

Given all of this, the first goal of exercise for shoulder rehab is to learn “setting” technique. Setting is your ability to control placement of the scapula and the GH in neutral positions.

Once you have mastered baseline setting we begin to apply the control learned in that activity to basic movements, like elevating at the shoulder out to the side, then in reaching back and then toward the front, as well as control in rotational movements.

In the video above we examine the initial stages of this type of a rehab protocol, which was pioneered by Lyn Watson and colleagues in Australia. These early stage considerations focus first on scapular setting control and then progress to  setting PLUS basic movements.

Progressions to more complex and the sport specific movement should be implemented in later stages of an MDI rehab project which can last 3+ months. This includes first scapula and GH control in increasingly difficult elevated positions, then in concert with strength training exercises like rows and pushups, and finally with sports motions like a swim pull or throws.

Again, motor control refers to this setting and then control of the shoulder though movement. I’m suggesting to you that motor control is the real goal of shoulder rehab, and that the exercises we practice in rehab are contexts of increasing complexity in which to practice that motor control!

Radical? Maybe not, but it might provide you with a conceptual framework that helps with understanding why it is that we are doing all of the goofy little exercises that we do when you come in to spend time with us in the clinic!

If you are dealing with an MDI situation, you may want to try the exercises shown in the video above. For progressions to advanced and then sport specific exercises come and see me (or the best physiotherapist you can find in YOUR city) for guidance specific to your unique circumstances.

 

Further reading (if you really want to impress your friends!)

Pizzari, T., Wickham, J., Balster, S., Ganderton, C., & Watson, L. (2014). Modifying a shrug exercise can facilitate the upward rotator muscles of the scapula. Clinical Biomechanics, 29(2), 201-205.

Watson, L., Warby, S., Balster, S., Lenssen, R., & Pizzari, T. (2016). The treatment of multidirectional instability of the shoulder with a rehabilitation program: part 1. Shoulder & elbow, 8(4), 271-278.

Watson, L., Warby, S., Balster, S., Lenssen, R., & Pizzari, T. (2017). The treatment of multidirectional instability of the shoulder with a rehabilitation programme: Part 2. Shoulder & elbow, 9(1), 46-53.