Muscle Contractions in Yoga

Trish Corley Author

Muscle contractions in yoga postures are not all the same. Do you know how muscles work?

There are Key Types of Muscle Contractions in Yoga That You Need to Understand!

.

"What muscles work in yoga? What muscles work in trikonasana/triangle pose? What poses can I do to work my biceps?" 

.

These type of questions are common from yoga students and yoga teachers. aSometimes, I answer and say "all of the muscles are working in triangle pose!"  The truth is, there is a good chance that almost all of the muscles are working in one way or another. In order to answer such questions, you must first understand how muscles "work".

.

The term "work" is rather vague when describing muscle activity. It makes a lot more sense to describe the action of muscles as "contractions."

.

Understanding some key anatomy terms that describe muscles will allow you to gain a more thorough understanding of what different muscles are doing during different yoga poses.

.
Stretching versus Strengthening

.

To start, the difference between stretching a muscle and strengthening a muscle must be distinguished. Stretching is an important part of all exercise and obviously a key component of one's yoga practice. Simply put, for a muscle to get stretched or become more flexible, the muscle must be lengthened.

For example, as you maintain a standing forward fold and reach your head towards your toes, you may feel the sensation of stretching in your hamstrings (the muscles that run down the back of your thighs). In this case, the two ends of the hamstring muscles are being stretched away from each other. The origin is at the hips and the insertion is at the back of the knees. The hips rise in the forward fold causing the hamstrings to lengthen out. This can happen passively - without any "work" from hamstring muscles themselves. 

.

The science of stretching has expanded significantly in recent years and a lot more could be discussed on the topic of stretching.

.

In the discussion of the types of muscle contractions in yoga, it should be noted that stretching can happen passively and actively. If a muscle is actively contracting and stretching, it is doing so via an eccentric contraction.

.

So let’s explore the 3 main types of muscle contractions in yoga.

After you have done 20 sun salutations or held Warrior II for ten breaths, you might start to feel your muscles "working". What you may be feeling is the fatigue in your muscles as they are contracting. It is through repeated muscle contraction (against some level of resistance) that the muscles get stronger.

.
There are 3 main types of muscle contractions in yoga:

A. Concentric

B. Eccentric

C. Isometric

.

All three of these types of contractions are used throughout your yoga practice.

.

___________________

Understanding the 3 types of muscle contractions is easier if you are clear on what the origin and insertion of muscles are.

The origin is where the muscle starts and the insertion is where it ends. In the case of the biceps (specifically the long head of the biceps), the origin is at the shoulder and the insertion is at the forearm. In the case of the hamstrings, the origin is at the sit bones (just above the hip) and the insertion is just below the knee.
_____________________

.

When a muscle performs a concentric contraction the muscle actively gets shorter. Each end of the muscle is attached to a different bone. As the muscle shortens, the insertion of the muscle moves towards the origin of the muscle.

Consider the biceps as shown in the image. The origin of the biceps is at the shoulder and the insertion is just below the elbow. As the muscle shortens, it pulls on ulnar (the lower arm bone) just below the elbow. This force draws the ulna up towards the shoulder. The result is elbow flexion (bending of the elbow).

A muscle's concentric contraction is what is often first understood. When someone is proud of how large their biceps are and wants to "show off their guns", they shorten the muscle via a concentric contraction in order to create a bulging muscle. Even if you are not looking to show off your bulging biceps, you use concentric contractions of the biceps in your yoga practice. For example, as you bend both of your elbows to bring your hands together in prayer position, your biceps contract concentrically.

.

Now consider how your biceps will create an eccentric contraction. During an eccentric contraction, the muscle lengthens (see image B). In this case, the insertion of the muscle moves away from the origin. The insertion (at the ulna/lower arm bone) moves away from the origin at the shoulder.

The muscle must control its action against the pull of gravity and therefore there is an active contraction. Eccentric contractions are used quite frequently in yoga. As you unfold your hands from prayer position and lower them down by your side, your biceps perform an eccentric contraction. You may be thinking this looks like the muscle is stretching. But there is a significant difference between a passive stretch and an eccentric contraction. In the case of lowering your hands down by your sides, your biceps are active. If you feel your bicep muscle as you lower your hand down, you will notice tension in the muscle. The primary purpose of the eccentric contraction is to provide controlled movement of the bones when moving with resistance.                                                              

.

During the concentric contraction of the biceps, the muscle has to overcome resistance of gravity. This includes the weight of the hand itself and the weight of any object that may be in the person’s hand. During the eccentric contraction, the biceps must control elbow straighteninges work in yog so that gravity does not just pull the hand down rapidly.

.

The 3rd type of contraction to explore is isometric. When a muscle is isometrically contracted the length of the muscle does not change. There is no movement of the insertion and therefore no movement of the joint. The muscle, is however, active. Isometric contractions are used primarily to maintain stability.

Isometric contractions are very common in yoga, particularly when poses are held for several breaths. As you move in and out of a pose, you are likely using a combination of concentric and eccentric contractions. When you hold a pose, you may be using more isometric contractions.

.

.

Try this simple activity to make sense of the various types of muscle contractions.

1. Sit comfortably and bring your hands to prayer at your heart center. You just performed a concentric contraction of the biceps in order to bend your elbows and bring your hands up towards your chest. Your biceps got shorter.

2. Now hold your hands in prayer position. Your biceps perform an isometric contraction in order to maintain that position. There is no change in the length of the muscle. The biceps stay in the shortened position you previously put them in.

3. Now slowly lower your hands from prayer position and bring them to your side. The biceps performed an eccentric contraction. Since you don’t want to flop your arms down by your side in carelessly, you use muscle activation to control the descent of your hands.

In order to get in and out of yoga postures, you use a variety of concentric and eccentric contractions until your body has reached a desired shape. Once you are ready to hold that shape, the muscles must maintain the shape via isometric contractions.

The longer you hold a pose, the longer the muscle must maintain the isometric contraction and it will eventually start to fatigue. That may be when you feel like getting out of the pose. Stay in the pose and let the isometric contraction get you stronger.

Understanding the terms described above will help you understand what muscles work in yoga!

Module 2 of Foundations covers details of muscle contractions in yoga. 

.

Yoga Anatomy School offers online and in person courses to make learning anatomy easy and practical! 

I recommend yoga teachers start with the Foundations of Yoga Anatomy. This is a 14 module course that will provide you with a clear understanding of yoga anatomy and leave you with more confidence and greater impact as a yoga teacher. This course, and so much more is available inside the Yoga Anatomy School membership. 

Categories: : Yoga Anatomy