Isometrics are powerful exercises that can be done by anyone and offers a host of benefits. They have been shown to decrease blood pressure, increase force output (i.e., strength), increase muscular endurance, increase vascularity, and there is some evidence that it can increase bone density and/or decrease bone loss.
The first thing I need to do is explain what an isometric exercise is. An isometric exercise is when the muscles contract but there is no visible movement that occurs. This is mainly done in 2 ways: 1) pushing against something that will not move, or 2) contracting one group of muscles against the muscles that would move the body in the opposite direction. Lying on your back with your arm at your side and pushing into the floor is an example of the first type. Flexing your “bicep” (i.e., elbow flexors) and holding that position would be an example of the second type because the elbow extensors (i.e., mainly the triceps) are stopping the elbow from bending as the elbow flexors contract. I primarily use the first method in the Muscle Activation Techniques work that I do and that most of you have experienced.
Two particular ways I use isometrics are to increase limited motion and to create strengthening in muscles that move a joint where there has been a history of pain. An example of the first technique is being covered in the bonus section of the Winter 2015 newsletter “Generic isometrics for the neck”. The idea behind increasing motion with isometrics is the basis of Muscle Activation Techniques. The basic premise is that if there is instability around a joint due to all the muscles not working to their full capacity then the body restricts motion. The isometrics can re-establish the ability of the muscles to contract on demand and therefore improve stability which in turn results in greater mobility in the joint. So if you find you have restricted motion, doing isometrics against a barrier in the direction of the restricted motion can be a powerful tool to make a change. The typical approach of stretching would be trying to take away the symptom of tightness/restricted motion but not address the underlying cause.
The second way of using isometrics may best be illustrated with an example. If pressing a weight overhead has caused pain or discomfort in the past or presently, doing the isometrics is a lower threat to the body because there is no movement. Generally I would have my client do an isometric in three positions, at the bottom, middle and top of the motion as long as it can be done pain free. So the overhead pressing would be done with the elbow close to the side, at about 90 degrees to the body, and with the arm overhead. A strap or a rope that is anchored under the same side foot could be used to press up against in these three positions. In Muscle Activation Techniques we use the formula of 6 repetitions held for 6 seconds each. Others recommend 30 second contractions in each of the positions.
So as you can see these simple exercises can have a great impact on both strength and mobility which are both needed for a fully functioning body and to enjoy all the activities of life.