Reliability and Validity for Measuring Active Hip Rotation with the Clinometer Smartphone Application™

Background: accurate range of motion (rom) assessment is an essentialcomponent of clinical practice to identify underlying deficits at the hip joint.hip joint active rom has been measured by goniometric methods in the clinicalsetting. more recently, the clinometer smartphone application has gainedattention for rom measures. however, minimal research has been identifiedfor the use of the clinometer smartphone application™ for hip rom. therefore,the purpose of this study was to determine intrarater and interrater reliability ofthe clinometer smartphone application™ as well as establishing its validity foractive hip internal rotation (ir) and external rotation (er).methods: a concurrent test-retest reliability study was conducted using aconvenience sample at three different sites. this study included 46 males and 30females (n=76) with an average age of 23.93 (5.37) years. five clinicians measuredeach participant’s active prone hip rotation at three different sites. three trialswere measured with the goniometer and with the clinometer smartphoneapplication™. intrarater reliability was assessed within one week for the fiveclinicians. interrater reliability was assessed between three clinicians located atthe same site.results: the intrarater reliability of goniometer was moderate to excellent(icc>0.73-0.96) for hip ir and moderate to good (icc>0.76-0.89) for er.similarly, smartphone intrarater reliability was good to excellent for ir(icc>0.81-0.96) and er (icc>0.77-0.90). the validity of the clinometersmartphone application™ when compared to the goniometer and had a verystrong relationship for ir (r=0.94-0.96) and er (r=0.84-0.89).conclusion: the results of this study suggest this application may be a valid andreliable alternative to the goniometer for clinicians when measuring active hiprotation in clinical practice.