Isometric Trunk Muscle Strength and Body Sway in Relation to Low Back Pain in Young Adults

In Brief Study Design. A cross-sectional study on young adults. Objective. To evaluate the relationships between low back pain (LBP), maximal isometric trunk muscle strength, and body sway among young adults. Summary of Background Data. The results of previous studies evaluating the association between trunk muscle strength and LBP are conflicting and heterogeneous. Furthermore, there are only few studies on the association between body sway and LBP. Methods. The subjects (n = 874) belonged to a subcohort of the Northern Finland Birth Cohort 1986 (mean age 19 years). Trunk muscle strength and body sway were measured from all subjects. LBP symptoms were inquired with a questionnaire, which was completed concurrently with the examinations. Latent Class Analysis (LCA) was used to cluster the subjects according to their LBP symptoms. Results. LCA analysis produced 6 clusters differing with respect to LBP symptoms. There were no statistically significant differences between the clusters in trunk muscle strength or body sway. Conclusion. LBP does not seem to be associated with maximal isometric trunk muscle strength or body sway in young adults. Maximal isometric trunk muscle strength and body sway were examined in 874 young adults at the age of 19 years. Latent Class Analysis was used to classify the subjects into subgroups according to the severity of low back symptoms. There were no statistically significant differences between the clusters in trunk muscle strength or body sway.