To clarify, I will only discuss isometric contraction here. Concentric and eccentric isotonic techniques come under the umbrella of MET but won’t feature in this post.
Most of my patients experience this technique in each session, and some will leave with a modified version to do at home. “MET” stands for Muscle Energy Technique, and works by activating the muscle in order to deactivate it below the level it previously could. This is particularly useful for deep muscles that are hard to reach, or tender, spasming muscles that might tighten up further when directly treated. I use it regularly to treat clicky jaws.
This technique works in two stages. First we engage the muscle isometrically, meaning the muscle is activated but resisted by an equal force- it isn’t getting any longer or shorter. The muscle isn’t working at full strength, normally about 20% of the maximum. At this level of power, the technique is effective but comfortable. We hold this for about 6 seconds.
The second stage is relaxing. Because the muscle has been gently activated, it is now more capable of relaxing further. When using this technique on tight shoulder muscles, the entire shoulder often drops significantly lower than the other at this point.
Another bonus of this technique is that it treats both the agonist (the muscle in question) and the antagonist (the muscle that works against it). For a more technical explanation, keep reading.
An Example: Tibialis Anterior
Tibialis Anterior is the main muscle on the shin (see diagram), responsible for flexing the ankle (bringing the toes and foot up) and turning the foot inwards. It can get quite tight as a result of awkward walking or overtight calf muscles. I’ve found that this exercise can be useful in preventing it from getting painful in the first place, particularly after power walking for a train.
Following the rules from before, we first want to engage the muscle. So while sitting down, hook the foot under some sturdy furniture close to the floor (a cupboard worked for me), pull the foot up with 20% of your force. After 6 seconds, relax the ankle and pull the leg up to passively stretch it. Hold this for at least 6 seconds, then repeat as required. See the gif below for clarity, but follow the 6 second rule! My software only allows 10 second long clips.
You can actually see my tibialis anterior contracting in the first half- this is how you know you’re doing it right.
The physiology
To understand exactly how this works, you need to know about the smaller structures in muscles. You don’t need to know the science to make it work, so don’t feel obliged to read this bit!
Golgi Tendon Organs work to stop a muscle from over-stretching
Muscle Spindles do the opposite, and stop a muscle from over-contracting
In the first movement, we contract the muscle against an equal and opposite force. This activates the muscle spindles to prevent damage by over-contracting. Essentially, they prep the muscle for relaxing.
When we come to the stretch, the golgi tendon organs come into play to prevent injury by over-stretching. This keeps the movement safe, and combined with the muscle spindles, helps the muscle to relax further than by simply stretching it.
Applying this to any muscle
MET works by activating the muscle and then stretching it, so as long as you know what a muscle does, you can MET it. Here are a couple of exercises I give as pure stretches:
The first is for trapezius, second for pectoralis major. Trapezius (or more specifically the upper fibres of trapezius) likes to shrug the shoulder, so for the stretch, we use the neck to do the opposite of a shrug relative to the neck. Pectoralis major brings the arm across the chest, so to stretch it we can take it away.
An MET for the upper fibres of trapezius would be to hold onto the chair and shrug the shoulder for 6 seconds, then leaning away for a further 6 seconds.
An MET for pectoralis marjor would be to fix the arm on a doorframe and bring the arm towards the chest for 6 seconds using 20% of your force, then step through the door to bring the arm back for a stretch.
Wikipedia is a good place to start if you’re interested in working out your own METs. The pages for individual muscles are essentially copied from old editions of Gray’s Anatomy so they’re really good for reference. If you get to grips with anatomical movements (flexion, extention, adduction, abduction etc) then you should be able to work out an MET for any muscle. The hard part is working out what to use for resistance. Elasticated bands are generally pretty good for muscles that won’t work with furniture.
