Reliability of Occupational Therapy Students Using the Figure-of-eight Technique of Measuring Hand Volume

Objective/Background

The figure-of-eight technique is a measure for hand volume that has been validated among experienced American clinicians and physical therapy students, but not among Middle Eastern occupational therapy students. The purpose of this study was to assess the intrarater and inter-rater reliability as well as concurrent validity of the figure-of-eight technique of measuring hand volume by 4th year (of a 5-year curriculum) occupational therapy students.

Methods

This study used a cross-sectional design of a single group with three-level repeated measures of five raters. Twenty-three healthy students participated in this study. Five raters (4th year occupational therapy students) performed three separate blinded figure-of-eight measurements of hand volume for each hand. Two independent examiners performed one volumetric measurement for each hand using a water volumeter. Intraclass correlation coefficient (ICC) were used to examine the intrarater and inter-rater reliabilities of figure-of-eight measurements. Pearson product-moment correlations were used to establish concurrent validity relative to the volumeter which is the gold standard.

Results

Intrarater reliability (ICC, 3k) ranged from .98 to .99 and the inter-rater reliability (ICC, 2k) was .99. The Pearson correlation coefficient for the concurrent validity was r = .929 (p < .001).

Conclusion

This study demonstrated that five occupational therapy students in the 4th year of a 5-year curriculum were reliable raters for hand volume using the figure-of-eight technique, after being trained and tested for competency. The students can use the figure-of-eight technique for systematically assessing hand volume with confidence in their clinical fieldwork.