IOPI Northwest

Why Measure Hand Strength?

If a patient is found to have weak tongue or lips, it is important to determine whether this is a symptom of a disease process affecting just the oral musculature, or whether it is part of a generalized weakness.  If, for example, an elderly person with a swallowing problem had tongue strength that was well below the mean tongue strength for their age group, but was still within the range of "low-normal," the conclusion that tongue weakness was highly related to their swallowing problem would be uncertain.  Perhaps they are just generally weak, compared to their peers. On the other hand, if their hand strength were at or above mean hand strength for this group, their tongue weakness would take on much more significance.

For some patients, such as those served by Occupational Therapists or Neurologists, accurate assessment of hand strength may be important in evaluation and treatment of the patient's primary problem.

Another use of the hand bulb is to familiarize a patient or subject with the strength-testing procedure.  It can be used by the clinician to demonstrate the tasks to be undertaken.  Then the patient can practice making a few maximum efforts with their hand.  Most people are much more familiar with grasping and squeezing with their hand than they are with pushing on a bulb with their tongue, so letting them practice a few times with the hand may, for some people, produce stronger and less variable tongue measurements.

Measurement

Hand strength is measured by recording the maximum pressure a person can produce in a special IOPI hand bulb when they squeeze it with their hand as hard as possible. The hand bulb is made of soft rubber, and has within it a small air-filled bulb that is immersed in an incompressible viscous fluid.  When the hand bulb is squeezed, only the small amount of air in the inner bulb is compressed, so the rubber bulb, as a whole, collapses only a small amount.  Thus the muscles of the forearm that produce the squeeze operate under near-isometric conditions.

The size of the hand bulb is appropriate for children as well as adults. It has been used with adults since 1990, and normal values of hand strength of young and old, men and women are available.