Validity and Reliability of a Wearable Goniometer Sensor Controlled by a Mobile Application for Measuring Knee Flexion/Extension Angle during the Gait Cycle

Abstract

Knee kinematics during gait is an important assessment tool in health-promotion and clinical fields. This study aimed to determine the validity and reliability of a wearable goniometer sensor for measuring knee flexion angles throughout the gait cycle. Twenty-two and seventeen participants were enrolled in the validation and reliability study, respectively. The knee flexion angle during gait was assessed using a wearable goniometer sensor and a standard optical motion analysis system. The coefficient of multiple correlation (CMC) between the two measurement systems was 0.992 ± 0.008. Absolute error (AE) was 3.3 ± 1.5° (range: 1.3–6.2°) for the entire gait cycle. An acceptable AE (<5°) was observed during 0–65% and 87–100% of the gait cycle. Discrete analysis revealed a significant correlation between the two systems (R = 0.608–0.904, p ≤ 0.001). The CMC between the two measurement days with a 1-week interval was 0.988 ± 0.024, and the AE was 2.5 ± 1.2° (range: 1.1–4.5°). A good-to-acceptable AE (<5°) was observed throughout the gait cycle. These results indicate that the wearable goniometer sensor is useful for assessing knee flexion angle during the stance phase of the gait cycle.

Validity of AI-Based Gait Analysis for Simultaneous Measurement of Bilateral Lower Limb Kinematics Using a Single Video Camera

“…For joint kinematics measurements during gait, the accuracy of AI-MA has been found to be comparable or superior to other existing methods [ 27 , 31 , 32 , 33 , 34 ]. In comparison with electronic goniometers and 3D-MA, Rivera et al [ 32 ] reported that the AEs in knee flexion–extension angles during a gait cycle ranged from 2.46° to 12.49°.…”

“…For joint kinematics measurements during gait, the accuracy of AI-MA has been found to be comparable or superior to other existing methods [ 27 , 31 , 32 , 33 , 34 ]. In comparison with electronic goniometers and 3D-MA, Rivera et al [ 32 ] reported that the AEs in knee flexion–extension angles during a gait cycle ranged from 2.46° to 12.49°. Similarly, Ishida et al [ 31 ] reported the AEs of 3.3 ± 1.5° for the same parameter, and the CMCs for waveform pattern comparison of 0.992 ± 0.008.…”

The Difference in the Assessment of Knee Extension/Flexion Angles during Gait between Two Calibration Methods for Wearable Goniometer Sensors

“…However, the previous study did not compare the errors between on-bench and on-body calibration methods. In addition, the errors occurring during the swing phase were larger than those occurring during the stance phase [22]. Calibration of the goniometer in our previous study was performed in the standing position and the preferred sitting positions of participants.…”

“…Measurements and calculations are simpler and less cumbersome than motion capture systems using multiple IMUs. In recent years, lightweight wearable electro-goniometers have been developed that can be controlled and analyzed using a smartphone application, and real-time visual biofeedback can be obtained [21,22]. Therefore, wearable goniometers have great potential for use in telehealth to facilitate rehabilitation effects after injury and are expected to be used in health promotion services that visit the elderly or local communities.…”

“…Recently, we reported acceptable accuracy (absolute error <5 • ) of a wearable goniometer sensor for assessing knee extension/flexion angle during gait [22], which is comparable to gait analysis using IMU systems [26] and human pose estimation [7,8,11]. We hypothesized that calibrating the goniometer on an individual's body would reduce errors compared to calibrating the goniometer on a bench [22]. However, the previous study did not compare the errors between on-bench and on-body calibration methods.…”