Prominent among the handicaps caused by several rheumatic diseases is the inability properly to perform the maneuver known as "making a fist" (grip)1: The degree to which this basic function is impaired depends on the nature and severity of the rheumatic process in any individual patient. Objective measurements of the strength of the grip would facilitate evaluation of incapacity due to such disease as well as improvement under a therapeutic regimen. Several extremely simple ergometers are herein described which have been developed for this purpose.
Most ergometers specifically intended for measuring the strength of the grip depend on the ability of the subject to compress a heavy steel spring; although crude, these instruments are of some value in measuring relatively vigorous grips. They are much too clumsy and insensitive to be used for measuring such extremely asthenic grips as may be encountered, for example, in patients with rheumatoid and
WAINERDI HR. SIMPLE ERGOMETERS FOR MEASURING THE STRENGTH OF THE HAND GRASP (GRIP)A Preliminary Report. JAMA. 1950;144(8):619–620. doi:10.1001/jama.1950.62920080005006c