Reliability and criterion validity of measurements using a smart phone-based measurement tool for the transverse rotation angle of the pelvis during single-leg lifting

ABSTRACT

Objective: The purposes of this study were to determine the intra-rater test–retest reliability of a smart phone-based measurement tool (SBMT) and a three-dimensional (3D) motion analysis system for measuring the transverse rotation angle of the pelvis during single-leg lifting (SLL) and the criterion validity of the transverse rotation angle of the pelvis measurement using SBMT compared with a 3D motion analysis system (3DMAS). Method: Seventeen healthy volunteers performed SLL with their dominant leg without bending the knee until they reached a target placed 20 cm above the table. This study used a 3DMAS, considered the gold standard, to measure the transverse rotation angle of the pelvis to assess the criterion validity of the SBMT measurement. Intra-rater test–retest reliability was determined using the SBMT and 3DMAS using intra-class correlation coefficient (ICC) [3,1] values. The criterion validity of the SBMT was assessed with ICC [3,1] values. Result: Both the 3DMAS (ICC = 0.77) and SBMT (ICC = 0.83) showed excellent intra-rater test–retest reliability in the measurement of the transverse rotation angle of the pelvis during SLL in a supine position. Moreover, the SBMT showed an excellent correlation with the 3DMAS (ICC = 0.99). Conclusion: Measurement of the transverse rotation angle of the pelvis using the SBMT showed excellent reliability and criterion validity compared with the 3DMAS.

KEYWORDS:

• Application
• measurement
• pelvic rotation
• single-leg lifting
• smart phone

Acknowledgments

We would like to thank subjects and assistant researcher in Lab of KEMA in this study for their helpful assistance in the preparation of this study.

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Funding

The authors acknowledge financial and administrative support provided by the Brain Korea 21 Program (grant number: 2016-51-0009), sponsored by the Korean Research Foundation.

Additional information

Funding

The authors acknowledge financial and administrative support provided by the Brain Korea 21 Program (grant number: 2016-51-0009), sponsored by the Korean Research Foundation.