Reliability and Validity of a Novel Approach to Measure Hip Rotation.

CONTEXT: Currently, hip-rotation range of motion (ROM) is clinically measured in an open kinetic chain in either seated or prone position using passive or active ROM. However, during activities of daily living and during sports participation the hip must be able to rotate in a loaded position, and there is no standard measurement for this.

OBJECTIVE: To determine if a novel method for measuring hip rotation in weight bearing will result in good to very good reliability as demonstrated by an intraclass correlation coefficient (ICC) of >.80 and to investigate if weight-bearing hip measurements will result in significantly reduced hip ROM compared with non-weight-bearing methods.

DESIGN: Repeated measures.

SETTING: Outpatient sports physical therapy clinic.

PARTICIPANTS: 20 healthy participants (10 men, 10 women) recruited for hip-rotation measurements.

METHODS: Three trials of both internal and external rotation were measured in sitting, prone, and weight bearing. Two therapists independently measured each participant on the same day. The participants returned the following day to repeat the same measurements with the same 2 therapists.

MAIN OUTCOME MEASURES: Degrees of hip internal and external rotation measured in prone, sitting, and loaded positions.

RESULTS: In general, the measurement of hip ROM across the different conditions was reliable. The intrarater reliability was .67-.95, while interrater reliability was .59-.96. Interrater reliability was improved when values were averaged across the measures (.75-.97). ICCs for active loaded ROM were .67-.81, while interrater ICCs were .53-.87. In general, prone hip ROM was greater than supine and supine was greater than loaded.

CONCLUSIONS: Loaded hip rotation can be measured in a clinical setting with moderate to good reliability. The rotation ROM of a loaded hip can be significantly decreased compared with unloaded motion.