Abstract
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. One test, which has been developed to evaluate neuromuscular impairments with movement, is the Functional Movement Screen (FMS). The reliability and validity of the FMS have been established for different healthy populations, but have not yet been examined for the LBP population because of a limitation of its original scoring system. The purposes of this study were to determine the inter-rater and intra-rater reliability and construct validity (the known-groups method) of the FMS using a modified scoring system in young adults with and without LBP. The FMS scores were modified by assigning a zero score only when there was an increase in the LBP during each movement test, not just for the presence of pain, as in the original FMS scoring system. Twenty-two participants with LBP (8 males and 14 females, 26.7±4.7 years old) and 22 age- and gender-matched participants without LBP (26.64 ±4.20 years old) completed the study. In addition, there was no group-difference in body mass index. Reliability was determined using intraclass correlation coefficients (ICCs). The total composite score was calculated, and a t-test was used to determine differences in the FMS scores between the two groups. The ICC values ranged from 0.93 to 0.98 for both groups, indicating excellent inter-rater and intra-rater reliability of the FMS composite score. In addition, the LBP group scored significantly lower than the group without LBP (p = 0.008). The results indicate that the FMS is able to distinguish between individuals with and without LBP based on their movement performance. Therefore, the FMS could be a useful test for clinicians to quantify movement quality and to assess movement restrictions in individuals with LBP.