Validity and reliability of wearable motion sensors in knee joint range of motion measurement

Abstract

Objective

Joint range of motion (ROM) is one of the factors that determine the function of the musculoskeletal system. This parameter must be able to be measured and recorded in an accurate and repeatable method. The aim of this study is to examine the validity and reliability of a wearable motion sensor, which is an inertial measurement units (IMUs) sensor, in measuring knee joint active flexion movement angles.

Methods

The study, an observational validation study, included 70 Health Sciences Faculty students between the ages of 18–25. The dominant knee joint ROM of the participants was measured by two raters with a digital goniometer (Meloq EasyAngle) and wearable motion sensors (MetaMotionRL).

Results

70 participants (40 female, 30 male) with an average age of 21.03 ± 1.34 years were included in the study. Intra-rater ICC was found to be 0.959 and inter-rater ICC was 0.961. An excellent correlation was found in the first rater's measurements of the Meloq EasyAngle and MetaMotionRL motion sensors (ICC: 0.934, %95CI [0.894–0.959]). Additionally, a significant correlation was found between the raters’ knee joint ROM measured with a digital goniometer and their ROM measured with a wearable motion sensor (p < 0.05).

Conclusion

It was concluded that the MetamotionRL device, a wearable motion sensor, is a valid and reliable method for measuring knee joint ROM. The use of IMU motion sensors is considered potentially important for monitoring and optimizing lower extremity kinematics during assessment and rehabilitation interventions.