Reliability and Validity of the Functional Movement Screen™ with a Modified Scoring System for Young Adults with Low Back Pain

Background Low back pain (LBP) is one of the most common complaints in individuals who seek medical care and is a leading cause of movement impairments. The Functional Movement Screen (FMS (TM)) was developed to evaluate neuromuscular impairments during movement. However, the reliability and validity of the FMS (TM) have not yet been established for the LBP population because of a limitation of its original scoring system. Purpose The purposes of this study were to determine the reliability and validity of the FMS (TM) with a modified scoring system in young adults with and without LBP. The FMS (TM) scores were modified by assigning a zero score only when there was an increase in LBP during the FMS (TM), not simply for the presence of pain, as in the original FMS (TM) scoring system. Study Design Reliability and validity study. Methods Twenty-two participants with LBP (8 males and 14 females, 26.7 +/- 4.68 years old) and 22 age- and gender-matched participants without LBP (26.64 +/- 4.20 years old) completed the study. Each participant performed the FMS (TM) once while being scored simultaneously and independently by two investigators. In addition, each participant's FMS (TM) performance was video-recorded and then was scored by another two investigators separately. The video-recorded performance also was scored twice six weeks apart by the same investigator to determine intra-rater reliability. Results The results showed excellent inter-rater and intra-rater reliability of the FMS (TM) composite score with intraclass correlation coefficients ranging from 0.93 to 0.99 for both groups. In addition, the LBP group scored significantly lower than the group without LBP (p = 0.008). Conclusions The results indicate that the FMS (TM) is able to distinguish between individuals with and without LBP, and that it could be a useful test for clinicians to quantify movement quality and to assess movement restrictions in individuals with LBP.