The Myotatic Reflex

The Myotatic Reflex (sometimes myotactic reflex) is probably our body's most unrecognised and unappreciated defence mechanism.

Forget about the immune system. When it comes to making it safely through the day, nothing comes close to the myotatic reflex.

Imagine that a muscle is able to constantly monitor it's own length and tension no matter what it's length, and is able to respond the instant it's length or tension changes. Without the myotatic reflex, controlled movement would be impossible.

The myotatic reflex starts in the muscle spindle which constantly and spontaneously produces an afferent impulse to the spine and therefore the brain - at a rate of at least 5 - 50 times per second.

Any little change in tension or stretch in the muscle will increase this feedback to spine and produce an rapid increase in muscle tone.

We know this as the knee-jerk reflex. A sudden increase in quadriceps length induces a quick firing at the anterior motor neuron.

Watch this animation to see it in action

The significance of the myotatic reflex is how it prevents damage to joints. When it is working properly, joints are protected from excessive movement or strain.

If the reflex is inhibited, joint will be damaged - causing pain initially, and osteoarthritis in the long term.

Assessing the patency of the myotatic reflex is the key to proprioceptive muscle testing and faster patient recovery.

Dedicated to strengthening your practice,

Simon King B.App.Sc(Chiro) DIBAK
www.expertmuscletesting.com