Clinical Assessment of Muscle Function With a Computer-Assisted Hand-Held Dynamometer.

The purpose of this text is to present the research findings of a series of studies that included the development and evaluation of an instrument for muscle testing. In the studies, a prototype of a computeraided hand-held dynamometer (CAH-DY) was designed and tested so that results could be compared with those obtained by physical therapists using traditional manual muscle testing techniques.

The second aspect of the text deals with the reliability of force measurements. Methods of analysis and reliability indexes are presented in order to asses the reliability of measurements in the clinical setting. The indexes presented give the smallest detectable difference and the confidence interval, both of which are derived from the standard error of measurement. For clinical decision making, these indexes should prove to be informative for physical therapists. Additionally, these indexes of reliability are presented for isometric force measurements of knee extension/flexion on patients.

Criterion-related validity of force measurements is presented as the third aspect of the text. This concerns the inferential use of these measurements to predict performance on ability level. Additionally, dynamic function tests to standardize performance of dynamic functional tests using the CAH-DY are presented. Also included is an evaluation study that was performed by physical therapists in a clinical setting. In addition to the kinetic and kinematic data, electromyographic data are used to present evidence of lower-extremity muscle activation patterns.

Included throughout the text is a series of line drawings, graphs, and photographs that are used to illustrate the key points of the presentation. These graphic displays add a great deal to the clarity of the technical aspects of the data and methods.

The method of the presentation is well organized but somewhat dull, and would have been better suited to a series of refereed journal articles. The technical aspects are clear, but may not be enticing to the clinician. One of the most interesting and informative aspects of the text is the explanation of measurement error and its impact on standardized measurements. Although the author makes a positive contribution to the importance of reliability data, this volume may be best suited for critical reading and evaluation as part of an academic course or journal club.

MaryAnn Clark, EdD, PT Seton Hall University South Orange, NJ