Measurement of maximum voluntary pinch strength:: Effects of forearm position and outcome score

• Published in: Journal of hand therapy Vol. 16; no. 4; pp. 326 - 336
• Main Authors: Stegink Jansen, Caroline W, Simper, Vicki Kocian, Stuart, Harry G, Pinkerton, Heather M
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2003; Elsevier Limited
• Subjects: Adult; Aged; Aged, 80 and over; Data Interpretation, Statistical; Female; Fingers - physiology; Forearm - physiology; Humans; Hypotheses; Male; Middle Aged; Posture - physiology; Reference Values; Standardization
• ISSN: 0894-1130; 1545-004X
• DOI: 10.1197/S0894-1130(03)00159-5

The purpose of this study was to determine the effects of forearm position and outcome score on key, fingertip, and three-jaw chuck pinch strength. Maximum voluntary key, fingertip, and three-jaw chuck pinches were performed by 135 healthy adults (20–88 years old) three times in a pronated, supinated, and neutral forearm position with the right and left hand using a B&L (B&L Engineering, Tustin, CA) pinch gauge. The highest, first, and mean scores of three pinch forces were recorded. Three 3×3 factorial repeated-measures analyses tested each type of pinch strength. Forearm position affected key and fingertip pinches (p<0.017; effect sizes <0.14) but not three-jaw chuck pinch. The highest score ranked highest followed by the first and then the mean of the three scores (p<0.017; effect sizes >0.53). Although the effects of type of outcome score were consistent, the statistically significant effects of forearm position and outcome score may be too small (<1 lb) to be clinically relevant. Standardized positioning during pinch strength measurement is still recommended despite these findings.