Test-retest Reliability and Intratest Repeatability of Measuring Lumbar Range of Motion Using Inertial Measurement Unit

Objectives : To assess the test-retest reliability and the intratest repeatability in measuring the cervical range of motion of healthy subjects with wireless microelectromechanical system inertial measurement unit(MEMS-IMU) system and to discuss the feasibility of this system in the clinical setting to evaluate the cervical spine musculoskeletal . Methods : 12 healthy people who were evaluated as noor mild-disability with neck disability index were participated. Their cervical motion were measured with IMU twice in consecutive two days for the test-retest reliability study. Intratest repeatability was calculated in the two tests separately. The calculated intraclass correlation coefficients(ICC) were discussed and compared with the those of the previous studies. Results : Cervical range of motion data were acquired and statistically processed: left rotation(61.64°), right rotation(65.12°), extension(61.98°), flexion(52.81°), left bending(39.31°), right bending(41.08°). ICCs were 0.77∼0.98(intratest repeatability) and 0.74∼0.93 (test-retest reliability) in the primary motion. In the coupling motion, intratest repeatability ICCs were 0.93∼ 0.99(transverse primary plane), 0.88∼0.97(saggital primay plane), and 0.77∼0.93(coronal primary plane). Test-retest reliability of coupling motion were 0.90∼0.97(transverse primary plane), 0.00∼0.72(saggital primary plane), and 0.04∼0.76(coronal primary plane). Conclusions : Several types of range-of-motion devices are now on use in many fields including medicine, but the practicality of the devices in clinical use is questionable for the convenient and economical aspects. In this study, we presented the reliability of cervical range of motion test with the developed wireless MEMS-IMU system and discussed its potential utility in clinical use.