Isometrics: The Secret to Gaining Strength Without Moving a Muscle

by Kimberly Painter, PT, DPT

What does it mean to perform an isometric exercise? 
Isometric exercises are when the joint angle and muscle length do not change during contraction. (Example: bridges, planks)

Can isometric exercises improve strength?
Yes, but typically only in that one position. This means that it would be beneficial to perform the same isometric exercise in several positions through the range of motion of that particular joint. It is recommended to start holding the isometric position until fatigued (can start with 10 sec and progress to 1 min depending on the exercise) and perform this 3x with rest breaks in between. Once you hit the point of fatigue, it shows that the muscle is starting to gain strength.

Who would benefit from isometric exercises?
As a general rule, movement should not be painful, if so then isometrics are where you would want to start to improve strength of the muscles and stability of the joints. Isometric exercises can be helpful for anyone; however, it is found to be the most beneficial for patients with arthritis and following injuries. The static position provides less compensation of other muscles and reduced chances of injury.

Isometrics provide a better neurological connection to the brain.
Our bodies are excellent at trying to “fix” itself without us even knowing it. In most cases, particular muscles will compensate more than others such as the pectoralis, hip flexors, or low back muscles. Since these muscles take over, we start to lack strength in other muscles that are important such as the shoulder complex, abdominals, and buttock muscles. When performing isometrics on the muscles that lack strength, it sends a stronger signal to the brain which makes your body more aware of its ability to activate these muscles during functional activities. Overall, your body is less likely to compensate.

Additional tips when performing isometrics.

  • DON’T FORGET TO BREATH! A common response is to hold your breath when trying to maintain an isometric. A good strategy is to breathe out when you position yourself and then count out loud as this makes you take breathes.
  • Follow up the isometric exercises with isotonic exercises. An isotonic exercise is when the muscle contracts and shortens through the movement. (Example: Bicep curls) The main reason for performing isotonic exercises following the isometrics is to further engage those muscles into a more normal movement pattern. This will also continue to strengthen the muscle through the entire range of motion.

Try it Out!
Here are some exercises for you to try!

Kimberly Painter, PT, DPT is a licensed doctor physical therapist at Mettler Center. Have questions about an injury? Ask an Expert. Call 217-398-9800 to schedule a free 30-minute consultation with a physical therapist or request an appointment online.