Tag: muscle contractions

Isometric Muscle Contractions

Before we dive into how Isometric contractions can benefit you, I will explain briefly the different types of muscle the contractions they do.

Types of Muscles

There are 3 types of muscle in our body, Cardiac, smooth and skeletal.

Cardiac muscle is the main tissue in the walls of our hearts. These muscles contract and relax to pump our blood. These muscles work without our conscious control.

The second type of muscle is Smooth muscle. Smooth muscles make up the walls of our organs like the stomach, bladder, and arteries(visceral organs). These muscles also work without our conscious control.

And the third type of muscle is skeletal muscle. Skeletal muscles are the muscles that allow body movement. When they contract they maintain posture, act on bones like a pulley system and generate body heat. These muscles function mostly under our conscious control.

Note: This is all possible due to muscles being able to contract and relax in opposing pairs.

Types of Muscle Contractions

  • Concentric

Concentric contractions cause the muscle fibers to shorten when they contract. For example, lifting an object from the ground requires a concentric contraction. The biceps in your arm will shorten to lift the object, like a weighted bicep curl.

  • Eccentric

Eccentric contractions allow the muscle fibers to lengthen while contracting. They allow movements to be controlled while resisting gravity. Like what is needed to lower an object to the ground rather than simply dropping it. 

Similarly, they work to slow down the velocity of an opposing muscle. 

For example, when kicking a ball, the front of the thigh (quadriceps) concentrically contract to bring the foot forward in the kicking motion. If the opposing muscles (hamstrings) did not have eccentric control it could not slow that motion down. There would be nothing to prevent your leg from continuing forward and kicking you square in the face.

  • Isometric

The third type of contraction is an isometric contraction. Isometrics will be the focus of this article.

What is an Isometric contraction?

An isometric contraction is a contraction where no movement occurs. Otherwise knowns as static, your muscle fibers are activated but are holding steady.

An example here is when we carry an object. We are simply holding that object steady, not lifting, not lowering just holding it in place.

So isometrics hold, they are critical in maintaining posture. 

Without the ability to perform isometric’s we would just be a pile of bones and muscles on the floor. There would be no tensile support to hold us upright.

What are the benefits of performing Isometric contractions?

Avoiding injury

Skeletal muscles aren’t all designed for the same job. There are two types, ones that cause strong contraction for a short amount of time. And others that contract weakly yet are required to contract for long periods of time.

Let us think of them as sprinter vs marathon runners. Power vs endurance.

Sprinting muscles create great force in short bursts. These muscles are normally the larger muscle groups needed for actions like lifting, catching, throwing, running, etc.

Marathon runners, on the other hand, need endurance. They need to be active for long periods of time but with less force. Our postural muscles support and stabilize our joints throughout the day and prevent us from flopping over. They are like marathon runners.

If the postural muscles are not strong enough or if they activate incorrectly our sprinter’s kick. The sprinters are not prepared to hold for sustained periods and fatigue rapidly.

Tired and fatigued muscles don’t function at optimal levels. They can cause imbalances, cramps and put you at risk of injury.

Activation and neuromuscular firing

Sometimes a muscle can in a sense “turn off”. This could be due to inactivity, injury or imbalances. Whatever the reason, in order to complete a required movement, the body will recruit other muscles that are simply not designed for the role.

An example of this is when Gluteus maximus (Glute max a buttock muscle) turns off in a sense. Excessive sitting causes the muscle to sit inactively and in a stretched position for long periods. This is common in office jobs and other occupations like truck driving.

Incorrect activation of Glute max while walking and moving your lower limbs can cause pain and sciatic like symptoms. As other muscles try to work harder to make up for the strength lost.

Another muscle located in the buttock (the piriformis) is responsible for this scenario of sciatic type symptoms. (The shooting pain down the back of the thigh).  As the piriformis is not cut out to do the job of glute max, it fatigues. It will then irritate the sciatic nerve if it spasms or cramps. This is known as piriformis syndrome and is not true sciatica.

What to do?

Glute Max needs to be strengthened. This is where isometric strengthening is useful.

Isolating the muscle and isometrically contracting will cue it to wake up and activate. This type of work encourages the nervous system to communicate with the muscle, Like a wake-up call (neuromuscular firing).

Rehabilitation

It is sometimes recommended to avoid movement for a period of time after an injury. And sometimes the pain alone will cause to avoid movement of that body part. In these situations, the muscle or muscles can weaken and begin losing mass within weeks. 

While it may be necessary to keep the affected joint immobile it is also important to maintain a level of strength to minimize muscle wastage. Isometric contractions permit strengthing without causing any movement at the joint.

In addition, the contraction of the muscle also helps move fresh blood to the area. And this is helpful as the blood transports oxygen and nutrients that aid the healing process and reduce recovery time.

How do you perform isometric contraction?

Isometrics require no special equipment therefor can be performed almost anywhere.  You only need to tense the area you want to work in.

its recommended to perform Isometric contractions in short bursts holding for 10 seconds at a time. While holding the contraction ensure you maintain slow, deep breaths. 

The number of repetitions and force of the contraction that suits your individual circumstance can be discussed with your Myotherapist.  It will be different depending on if you are recovering from an injury or wanting to simply “switch on” (activate and strengthen) a muscle.

Here are a couple to try

Core engagement

Do this standing or seated.

It’s as simple as contracting (Tightening) your stomach muscles.

  1. Draw your belly button back towards your spine and slightly up in the direction of your head. (Core activation/TVA)
  • To increase resistance, activate core then lift your feet slightly off the ground (while seated).
  • Use your hands to push your knees back towards the ground, matching the resistance.

Isometrics are great at strengthening your core and you can do them anywhere, any time.

Neck strengthening

Do this standing or seated.

  1. Clasp your hands together behind your head.
  2. Draw your elbows and shoulder blades backward.
  3. Push your head back into your hands at the same time as pushing your hands forward into the back of your head. (DO NOT tilt head! Simply draw it backward, creating a double chin, to meet resistance)

This strengthens upper back and neck muscles while stretching the front of your chest

 

Isometrics temporarily restricts blood flow to the region and can cause blood pressure to spike. So consult your doctor prior to commencing any new exercise routines. Especially if you are pregnant, have high blood pressure or heart disease.

Any unusual symptoms such as headaches, nausea or dizziness stop immediately and consult your doctor.

 

Thanks for reading, I hope you have found this article to be useful.
If you have any questions or would like to book in a Myotherapy or massage session you can contact me via the below information.

By Rachael Sloothaak