Objective: To determine the reliability of physiotherapists' visual observation of head and neck alignment.
Design: An interrater reliability study with an evaluation of concurrent validity using a gold standard.
Setting: Physiotherapy Research Laboratory, Princess Alexandra Hospital.
Participants: Three physiotherapist raters, one male model exhibiting 53 test positions.
Main outcome measures: Assessment of head and neck alignment required rating the direction of deviation (in each of the three planes of movement), and the magnitude of deviation.
Results: All three assessors were correct across all domains of direction and magnitude of deviation for only 10 of the 53 test positions. There was a mean of 2 total errors (out of a possible 12) per position. The more planes of deviation involved in a position, the more total errors there were. Most errors were made in the axial rotation (transverse) plane. Where a lateral flexion (coronal) plane of deviation was involved, there were more total errors; however, this plane itself had the fewest number of errors. Positions with a combination of both lateral flexion and axial rotation deviations were often mistaken for a flexion/extension (sagittal plane) deviation. Fewer errors were recorded for positions of 10-degree deviation compared to 5-degree deviations.
Conclusions: Visual assessment of head and neck alignment by physiotherapists is of questionable validity for identifying deviations in the order of 5 degrees from neutral. For deviations of 10 degrees in a single plane visual, observation is comparable to other clinically available tools.