Translated Abstract
Background: Cervical range of motion（CROM）is a very good evaluation index of cervical movement function. At present, there are a lot of tools and methods to measure CROM for the clinical and research purpose, including simple visual, tape, inclinometer, cervical range of motion device, X-ray, etc. But most of them are controversial and there is still no a widely acceptable, objective and feasible method or tool. Coda motion 3-D analysis system is a new type instrument that can measure the three dimension joint movement. It has been widely applied in the motion measurement of limbs and gait analysis, because it has the advantage of no radiation, real-time, dynamic and objective measuring. However, there is few research related to measurement of CROM using the Coda motion 3-d motion analysis system. According to the principle of the instrument, our research group design the concrete methods to measure CROM using this device, and verify the reliability of the system to measure CROM at the beginning of the design. The result shows that the device has a good reliability to measure the normal active CROM. Nevertheless, because the sample size is small, the result may be limited. And research about the validity of the Coda motion 3-D analysis system is lacking.
Objective: To assess the reliability and validity of Coda motion 3-D analysis system for measuring cervical range of motion in nomal subjects, and explore a new method or tool for the clinical and research purpose.
Methods: 1）Forty-three volunteers(male 31, female 12) with no known history of cervical disorder within three months prior to the measurement were involved in this study. All the measurement of cervical range of motion were conducted by two trained investigators using the Coda motion 3-d motion analysis system. Sitting on a seat without back,volunteers were recommended to excise their necks and heads in six directions for 3 times. Tester M1 and tester M2 measured all the volunteers once independently, then tester M1 measured all of them twice after a short rest. Intraclass correlation coefficient(ICC) was applied to evaluate the inter-tester and intra-tester reliability of Coda motion 3-D analysis system for measuring the normal active cervical range of motion. 2) Nineteen healthy volunteers(male 14, female 5) were involved in this study. Cervical flexion,extension and lateral extension range of motion were measured by the Coda motion 3-D analysis system and X-ray simultaneous. Scatter diagram and Pearson correlation coefficient were used to evaluate the validity of Coda motion 3-D analysis system for measuring the normal active cervical range of motion.
Results: 1)Coda motion 3-D analysis system demonstrated a good intra-tester reliability for measurement of cervical range of motion in healthy volunteers(ICC 0.85~0.94, flexion 0.85, extension 0.93, total extension, flexion 0.94, right lateral flexion 0.88, left lateral flexion 0.91, total lateral flexion 0.92, right rotation 0.87, left rotation 0.88, total rotation 0.90), and a good inter-tester reliability for measurement(ICC 0.84~0.96, flexion 0.84, extension 0.95, total extension, flexion 0.96, right lateral flexion 0.89, left lateral flexion 0.92, total lateral flexion 0.93, right rotation 0.89, left rotation 0.86, total rotation 0.88). 2) Coda motion 3-D analysis system demonstrated a good linear relation with X-ray measurement in cervical lateral flexion(left lateral flexion, r=0.8;right lateral flexion,r=0.52). In the direction of flexion and extension, the correlation coefficient of total total extension and flexion mobility was very high (r=0.92), while separate flexion and extension were low. The correlation coefficient of left lateral flexion(0.80) was better than the right side (0.52) . The correlation coefficient of flexion and extension were both poor(extension 0.44, flexion 0.26).
Conclusion: The results of the study demonstrate Coda motion 3-D analysis system has a very good reliability for measurement of cervical range of motion, and a good validity for measurement of lateral flexion in healthy subjects. Although the correlation coefficient of separate flexion and extension is poor, the total extension and flexion is good, which can reflect the actual cervical extension and flexion range of motion. Coda motion 3-d analysis system is accurate, convenient, safe, non invasive, no radiant, which can be used to measure the normal active cervical range of motion.
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