September 2011

Reliability, Validity, and Precision of a Handheld Myometer for Assessing in Vivo Muscle Stiffness

Steven M. Zinder and Darin A. Padua
Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, USA
Journal of Sport Rehabilitation - September 2011, Technical Notes 1(3) (DOI: 10.1123/jsr.2010-0051)

A handheld myometer is a device purported to accurately measure muscle stiffness in individual muscles. Previous research has shown that other methods of muscle-stiffness measurement (e.g., damped oscillatory and passive length-tension) are sensitive to levels of muscle force output. Sex differences have also been observed using these other measures of stiffness. Thus, we hypothesized that if a handheld myometer provides a valid assessment of stiffness that we would observe similar patterns. Therefore, the purpose of this investigation was to examine the reliability and validity of a handheld myometer for assessing skeletal-muscle stiffness.
The results of this study suggest that a handheld myometer may be an effective clinical measure of active muscle stiffness. The valid, reliable, and precise measurements it collects combined with its ease of use and ability to measure active muscle stiffness in specific, individual muscles make it a valuable tool to any practitioner or researcher interested in in vivo biomechanical properties of skeletal muscle. Although myometry may not completely replace the computer algorithms and sophisticated hardware needed in many applications, this simple device shows promise as a tool in many research laboratories and therapy clinics.