Background A screening test evaluates a functional movement by assessing an athlete's functional limitations, weaknesses, or impairments that may increase the risk of injury for the athlete.
Objective To assess the inter-rater reliability and subject variability of the Functional Movement Screen (FMS) and to analyze the use of video scoring as opposed to live scoring.
Design A reliability study. Each athlete was tested and retested, 1 week apart by the same rater, who also scored the athlete's first session from a video recording. These video recordings were then scored by five other raters.
Setting Human Performance Lab using two standard video cameras (sagittal and frontal views) and SiliconCoach video capture software.
Participants 21 female (19.6±1.5 years, 64.4±5.1 kg, 1.7±0.1 m) and 19 male (19.7± 1.0 years, 80.1 ±9.9 kg, 1.9±0.1 m) Varsity athletes from swimming, soccer, volleyball, cross-country and gymnastics volunteered to participate, along with six raters.
Assessment The FMS consists of seven tasks that focus on mobility and stability. Each task is rated out of 3, with pain being an automatic zero, for a total score out of 21. Raters (6) looked for malalignment and asymmetry.
Main outcome measurement The Krippendorff alpha (Kalpha) was used to assess the reliability of each of the three tests: inter-rater, test-retest, live versus video.
Results The Kalpha for the inter-rater, the test-retest, and the live/video was 0.3806, 0.6161, and 0.9096, respectively.
Conclusion Inter-rater reliability results show that clinicians should avoid comparison across multiple raters. It is possible that with more training this value may increase. Fortunately, if a single rater is used, clinicians can be confident that a change in the FMS score is due to a change in the athlete as the test-retest produced good reliability. This study also demonstrates that streamlining the FMS process with the use of video capture is appropriate.