Measurement of hand joint range of motion in rheumatoid arthritis: Repeatability and variability

Abstract

Purpose: To quantify the reliability of range of motion measurements in patients with rheumatoid arthritis, and to see whether a warm-up exercise improves reliabilityMethod, Materials, and Analyses: Eighteen patients (36 hands) with rheumatoid arthritis (per American Rheumatology Association criteria) of variable duration and severity volunteered for the study. Thirty-three patients were required to find a 10-degree difference in the reliability of range of motion measurements. The patients' active hand range of motion was measured on two mornings of the same week, using American Society of Hand Therapists' clinical assessment protocols. Before one set of measurements they completed a 5 minute hand warm up, consisting of opening and closing the hand then repeating figure of eight motions of the wrists. The order of warm-up/no warm-up was alternated. The examiner performed intra-rater reliability assessments prior to the study. The differences between test and retest were calculated and plotted to identify any systematic bias between test and repeat. Paired t-tests were performed to determine the difference between right and left hands, between test and repeat and between warm up and no warm up.Results: The intrarater reliability of the examiner was less than 3 degrees when measuring healthy volunteers. Performing a 5-minute warm up before measuring active range of motion did not increase the reliability of measurements. There was no systematic bias between test and repeat (i.e., from learning effects or fatigue). The reliability of extension motions was greater than that of flexion motions.Conclusion: Overall error was between 10 and 12 degrees when active range of motion was repeated in patients with rheumatoid arthritis.Relevance to Hand Therapy: The reliability of range of motion measurements for patients with rheumatoid arthritis has an error margin of more than 10 degrees, and it is variable depending on the joint and the motion being measured. The wrist and flexion motions of the digits are the least reliable. Purpose: To quantify the reliability of range of motion measurements in patients with rheumatoid arthritis, and to see whether a warm-up exercise improves reliability Method, Materials, and Analyses: Eighteen patients (36 hands) with rheumatoid arthritis (per American Rheumatology Association criteria) of variable duration and severity volunteered for the study. Thirty-three patients were required to find a 10-degree difference in the reliability of range of motion measurements. The patients' active hand range of motion was measured on two mornings of the same week, using American Society of Hand Therapists' clinical assessment protocols. Before one set of measurements they completed a 5 minute hand warm up, consisting of opening and closing the hand then repeating figure of eight motions of the wrists. The order of warm-up/no warm-up was alternated. The examiner performed intra-rater reliability assessments prior to the study. The differences between test and retest were calculated and plotted to identify any systematic bias between test and repeat. Paired t-tests were performed to determine the difference between right and left hands, between test and repeat and between warm up and no warm up. Results: The intrarater reliability of the examiner was less than 3 degrees when measuring healthy volunteers. Performing a 5-minute warm up before measuring active range of motion did not increase the reliability of measurements. There was no systematic bias between test and repeat (i.e., from learning effects or fatigue). The reliability of extension motions was greater than that of flexion motions. Conclusion: Overall error was between 10 and 12 degrees when active range of motion was repeated in patients with rheumatoid arthritis. Relevance to Hand Therapy: The reliability of range of motion measurements for patients with rheumatoid arthritis has an error margin of more than 10 degrees, and it is variable depending on the joint and the motion being measured. The wrist and flexion motions of the digits are the least reliable.