An isometric muscle contraction is when force is applied to a static object so there is no movement at the joint. Apparatus can be used to measure the maximum force applied.
purpose: this test measures back and leg strength
equipment required: strength dynamometer, usually composed of a cable tensiometer.
pre-test: Explain the test procedures to the subject. Perform screening of health risks and obtain informed consent. Prepare forms and record basic information such as age, height, body weight, gender and test conditions. Check and calibrate equipment if required. See more details of pre-test procedures.
procedure: Make sure the dial is reset to zero before you start. Stand upright on the base of the dynamometer with your feet shoulder width apart. Let your arms hang straight down to hold the center of the bar with both hands, and with the palms facing toward the body. Adjust the chain so that the knees are bent at approximately 110 degrees. In this position your back should be bent slightly forward at the hips, your head should be held upright, and you should look straight ahead. Then without bending your back, pull as hard as possible on the chain and try to straighten your legs, keeping your arms straight. Pull against the weight steadily (no jerky movements), keeping the feet flat on the base of the dynamometer. Maximum performance will result when your legs are almost straight at the end of the lift. If not, adjust the chain length and starting position.
scoring: read the result from the dynamometer
advantages: this is a simple test to perform
disadvantages: it is only possible to test one person at a time. The equipment is not readily available
variations: different muscle groups can be tested by adjusting the length of the chain, and the degree of leg bend.
- Another isometric leg strength test
- Other strength tests