2017 Volume 36 Issue 4 Pages 481-487
Objective: The clinical measurement of range of motion (ROM) is a fundamental evaluation procedure of physical function. In this study, we investigated the reliability of a new ROM measurement with a non-contact three-dimensional (3-D) surface scanner.
Methods: Measurement objects were the active ROM of right elbow joints and ankle joints of eight healthy adults. We measured the ROM with two procedures. One was manual ROM measurement by six physical therapists (PT) with a goniometer. Another was a new ROM measurement, producing 3-D images of the joints with a 3-D surface scanner, which were measured by six doctors. We compared the two measurement procedures and analyzed inter-rater reliability with the intraclass correlation coefficient (ICC) and measurement time with the Mann-Whitney U test (MWUT).
Results: ICC (3,1) were 0.66 and 0.80 at elbow flexion, 0.35 and 0.80 at elbow extension, 0.39 and 0.85 at ankle extension, and 0.49 and 0.88 at ankle flexion with manual measurement and with 3-D scanner image measurement, respectively. The inter-rater reliability of the 3-D scanner image measurements was higher than the manual measurements at both joints. It took significantly longer time for the measurement with the 3-D scanner (176.0±63.3 seconds) than with manual measurement (34.5±3.1 seconds) at the elbow joint (P<0.01, MWUT). Similarly, it took a significantly longer time for the measurement with the 3-D scanner (213.6±55.4 seconds) than with manual measurement (58.2±4.8 seconds) at the ankle joint (P<0.01, MWUT).
Conclusion: ROM measurement with a 3-D scanner was a more reliable procedure than manual ROM measurement. However, it was not nearly as fast as manual measurement. Examiners must become familiar with the technique in order to shorten measurement time. The non-contact 3-D surface scanner is a very useful tool, and in the future, it can be applied not only to ROM measurement, but also to three-dimensional and sequential evaluations of joint deformation in patients with rheumatoid arthritis.
