Factors influencing the reliability of the universal goniometer in measurement of lower limb range of motion : a literature review

The universal goniometer (UG) is commonly used in clinical practice tomeasure lower-limb joint range ofmotion (ROM). Reliability of the UG is essential to ensure consistency of measurement between and within practitioners. Clinically, it is important to understand how reliability may be affected by various factors. An electronic and manual literature search was conducted to determine the reliability of the UG. A variety of search terms were used to search between 1980 and July 2015. Articles sourced were graded according to the Scottish Intercollegiate Guideline Network guidelines. Articles reviewed included bothmeasurements of healthy subjects and those with different pathologies. Active and passive lowerlimb ROMs were studied, and intratester and intertester reliability were examined. Twenty-one studies were included and fully reviewed. Most studies indicated that UG reliability was best when used to measure ROM in healthy subjects in comparison to patients. The limited number of studies measuring active motion compromised the ability to make comparisons with measuring of passive ROM. It was reported from the studies investigating both intratester and intertester reliability that intratester reliability was higher than intertester reliability. Reliability ofmeasurements varied depending on the joint measured. Tester training and standardization of the measurement procedure led to increased reliability, and there was a suggestion that involving two testers in the measurement procedure may have a beneficial effect. This literature review highlights variation in studymethodology used, which reduces the ability to directly compare studies. Clinicians should be aware of the variability of reliability of the UG and the effect of different factors when interpreting measurements taken with this instrument. Further research is required to investigate the effect different factors may have on the reliability of the UG and the possibility of using protocols and technology to increase reliability when measuring joint ROM