Normative data for the Baseline® 5 position hydraulic pinch meter and the relationship between lateral pinch strength and pinch span

Abstract

IntroductionThe Baseline® 5 position hydraulic pinch meter allows pinch strength assessment at five different pinch spans. The present study used this newly developed meter to assess where pinch span force is the greatest as previous literature is conflicting. Purpose of the StudyThe primary aim of the study was development of normative data using health subjects, whereas the secondary aims were to evaluate meter inter-rater reliability and to identify in which pinch span the greatest force was produced. Study DesignThis is a clinical measurement, cross-sectional study. MethodsTen occupational therapy student raters examined inter-rater reliability by calculating an average intraclass correlation. Recruitment of normative data subjects occurred across various locations in West Michigan to include a diverse population and followed testing procedures recommended by the American Society of Hand Therapists. Data were stratified by age categories and sex to develop normative standards. Data were analyzed using a one-way repeated measures ANOVA and a three-way mixed ANOVA. ResultsNormative data were calculated from a sample of 605 subjects (292 males and 313 females). One-way ANOVA demonstrated a significant difference at the five different spans, noting a small effect size. Also noted were a nonsignificant three-way interaction between age category, pinch spans, and sex using both the right and left hands, along with a significant two-way interaction between spans and sex bilaterally. DiscussionThe meter showed an excellent inter-rater reliability with an intraclass correlation = .98 and indicated the pinch span that produced the greatest amount of force was not consistent with previous literature.