Posture Vs. Power: 2 Types of Muscle Fibers

We have many different types of tissues in our bodies that all serve difference purposes. Muscular tissue is classified by its ability to contract, or actively shorten and lengthen. Muscular tissue is present in many areas of our bodies and serves different functions beyond just body movement, such as keeping our organs active and blood pumping. Today I want to discuss skeletal muscle with you, which is what we typically think of when we hear the word "muscle" and what ultimately allows us to move.

Muscles are really an amazing anatomical feature. They are made up of many individual muscle fibers that are able to all work together as a unit to produce a desired movement. Every time you do so much as lift a finger, there are thousands of little muscle fibers active to allow that movement to happen. When we are moving multiple body segments in coordination with one another, such as during a pirouette or grande jete, the amount of different physiological events that must occur in perfect synchronization with each other is mind boggling. It is like our cells and tissues are doing a dance of their own! So how is it possible for our bodies to perform these perfectly coordinated movements and demonstrate such high level muscle control? Well, part of it involves the combination of 2 different types of muscle fibers.

All skeletal muscle contractions are voluntary, however there different types of contractions that are able to be produced. This depends on if the muscle is Type 1 or Type II.

Type 1 muscle fibers are also known as slow twitch fibers. Their purpose is to produce low level contractions over prolonged periods of time. In other words, these are our postural muscles. This includes muscles like our spinal stabilizers, soleus muscle in the calf, and transverse abdominus muscle (deep core). Every time you sit down in class for an hour, it is your postural muscles that are able to keep you upright and prevent you from slumping down in your chair. Because of their ability to be contracted over long periods of time, they do not fatigue as easily.

Type II muscle fibers are also known as fast twitch fibers. Their purpose is the opposite: to produce high intensity muscle contraction for very short periods of time. These are our powerhouse muscles, such as the quads. These muscles are what allow you to perform power movements, such as jumping and tumbling. They are only made to be active for short bursts, so they can fatigue much faster than type 1 fibers. Type 2 fibers are broken down into 2 categories, but that is beyond the scope of this blog.

Both types of muscles are equally important. Although they serve different purposes, they must work together to produce all the different movements our bodies are capable of. Think about it this way: each time you do a develope, while your gesture leg moves your upper body and trunk must remain relatively still. The ability for this to occur comes from type 1 muscle fibers working to keep your trunk upright and in good posture, while type 2 muscle fibers are working to generate the power to lift your leg.

It is important to understand how to exercise both types of muscles, because you need them both for different activities. In my next 2 blog posts, I will discuss ways that you can work on postural muscles and power muscles to create the perfect balance in your body. This should not only improve your dancing, but help you overall feel stronger and more stable in your day to day lives.

To be continued......

       Owner- Jenna Siracuse Loewer, DPT  
       Fax: 1-833-215-8081


       Inside of CrossFit Durable

       5401 Merchants View Sq.

       Haymarket, VA 20169


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