Muscle Contraction – How Does It All Work?

by Paula Allia PT, DHSc, MTC, OCS

There are a lot of muscles that work each day in the body that provide us with function and stability. The details of how all of this physiology works is taken for granted, that is until problems occur that may interfere with normal regulation of the mechanisms in place.

Thus, awareness that there is an elaborate system in place needs to be a consideration in normal everyday activities. Muscles are made up of proteins that, when regulated by the nervous system, work together to cause a contraction in a muscle.

The contractile element in a muscle is called a sarcomere. Protein filaments in this sarcomere with a neuromuscular process and the help of calcium and energy (ATP), cause the filaments to slide closer together thus shortening a muscle and ultimate movement of bone or joint.

Providing length to the muscles, sarcomeres are laid down in series. The sarcomeres that are aligned in parallel, when contracting together, give strength to a muscle.

Muscle cells have mitochondria, the powerhouses of a cell. This is similar to the powerhouse of a building. The mitochondria produces energy in the form of ATP. The process to the muscle filaments sliding together needs ATP as the muscle fiber slides and creates tension. If there was no ATP muscle could not contract.

CoQ10 is a supplement that helps the mitochondria be healthy, producing the ATP for energy utilization. Many doctors have patients taking this supplement. When a muscle contracts, there is an increase overlap of the muscle filaments. This causes tension in the muscle.

If the filaments continue to overlap further, there is ultimately a pull on the tendon which is at the ends of muscles. Tendons attach to the bone rather than into the bone and pull on the bone, thus causing motion. The length of these sarcomeres and its working relationship to other sarcomeres can causes different types of muscle contractions.

All of these play important roles in stabilizing and/or moving the body. In addition to the intricacies of muscle contraction, there are also different types of muscle fibers. Some work faster than others and some have more endurance than others.

Fast twitch muscles fibers work faster than slow twitch. Some of these fast twitch fibers last longer contracting than others. Muscle fibers that last the longest are the slow twitch muscle fibers. These fibers vary depending upon the muscle. Some have more of one type of fiber than another.

If someone jumps fast and high then there must be a component of one of the fast twitch fibers. A muscle with only slow twitch fibers would not contract as quickly. Also, when demands are high, fatigue can set in. Even length is important to carry out a successful movement.

If a joint is approximated more the muscles may be limited in how much tension it can create. Tight muscles that are suddenly stretched may cramp more than a muscle than has better extensibility.

Lengthened muscles that suddenly need to contract may not provide the proper tension and thus stability for safe activities.

In summary, muscle movements are complicated and mostly taken for granted. Strengthening and stretching muscles properly seem simple BUT doing the right things to enhance your performance and function is key. Seek out the right people to help you take control of your movements.

Here’s to Your Health
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