An isometric exercise tool is a device used to exercise most body parts including the
wrist
In human anatomy, the wrist is variously defined as (1) the Carpal bones, carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known ...
and is often used as part of
physical therapy
Physical therapy (PT), also known as physiotherapy, is one of the allied health professions. It is provided by physical therapists who promote, maintain, or restore health through physical examination, diagnosis, management, prognosis, patient ...
or in order to build muscle strength in a low impact manner. Devices can range in size from large bulky machines used by physicians to small hand-held devices that can be used by an individual. Isometric devices have been used for centuries. The first devices did not display the users' output; nowadays there are devices that can digitally output the users force. Before that some devices used an analog format.
How it works
Isometric exercise tools perform exercises or strength test using static contraction of a muscle without any visible movement in the angle of the joint. This is reflected in the name; the term "isometric" combines the prefix "iso" (same) with "metric" (distance), meaning that in these exercises the length of the muscle does not change, as compared to ''isotonic contractions'' ("tonos" means "tension" in Greek) in which the contraction strength does not change but the joint angle does. New isometric exercise tools often used force gauges and a micro processor and then output the force onto an LCD screen or store the information later to be downloaded onto a computer.
Medical uses
Isometric exercises can also be used at the bedside to differentiate various
heart murmur
Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel. This occurs when turbulent blood flow creates a sound loud enough to hear with a stethoscope. Turbulent blood flow is not smooth. The sound di ...
s; the murmur of
mitral regurgitation
Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. gets louder as compared to the quieter murmur of
aortic stenosis
Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse ove ...
.
Comparison with dynamic exercises
Isometric exercises have some differences in training effect as compared to dynamic exercises. While isometric training increases strength at the specific joint angles of the exercises performed and additional joint angles to a lesser extent, dynamic exercises increase strength throughout the full
range of motion
Range of motion (or ROM), is the linear or angular distance that a moving object may normally travel while properly attached to another. It is also called range of travel (or ROT), particularly when talking about mechanical devices and in mechanic ...
. Generally speaking however, people who train isometrically don't train through a full range of motion as the strength gained at the training joint angle is where they require it. While dynamic exercises are slightly better than isometric exercises at enhancing the twitch force of a muscle, isometrics are significantly better than dynamic exercises at increasing maximal strength at the joint angle.
Flexibility may be increased when isometrics are performed at joint range of motion extremes. These isometric contractions recruit muscle fibers that are often neglected in some dynamic exercises. For example, gymnasts are extremely strong at great ranges of motion through the practice of isometric holds.
See also
*
Dynamic tension
References
External links
Public domain pamphlets on isometric exercisesExample of an isometric exercise device
{{DEFAULTSORT:Isometric Exercise Device
Physical exercise
Bodybuilding