Measuring a person's grip strength over time can be a very useful diagnostic tool and motivator for patients. In keeping with the practical theme of the conference this paper will address the extent and limitations of grip strength testing using Jamar-like hand grip dynamometers, based on the best evidence available. It will discuss the reliability and validity of grip strength values. Research has shown that the most accurate way of predicting the grip strength of one hand is by knowing the grip strength of the other hand, assuming that the other hand is injury free. However, many things influence the grip strength of both hands from day to day.
This paper is based on Anita's extensive PhD research into the reliability of grip strength measurements. The issues will be illustrated with a series of case studies. It will look at the different ways to use a grip strength dynamometer, over various time intervals and on different handle sizes. It will discuss the standard procedure for and the interpretation of the Rapid Exchange Test, the 5 Handle Positions Test and Sustained Grip Testing. It will give examples of how to use a hand grip dynamometer to assist in diagnosing and recording progress in conditions such as Tennis Elbow. This paper will focus on the clinical reasoning needed to accurately interpret grip strength results. The various normative data bases for grip strength and the impact of hand laterality will also be discussed.