Axial Spondyloarthritis is associated with changes in lumbosacral loading during daily activities

There is currently little insight in lumbar spine loading during activities of daily living in patients with axial spondyloarthritis. Furthermore, it is unclear how inflammation or ankylosis-related mobility limitations in patients with axial spondyloarthritis affect lumbosacral loading, and if lumbar movement profiles have an effect on lumbosacral loading as well. Therefore, the aim of this study is to get more insight in the differences in peak and cumulative lumbosacral loading in patients with axial spondyloarthritis during activities of daily living.

Three-dimensional motion analysis with integrative force-plates was used to calculate peak lumbosacral moment (peak loading) and lumbosacral moment impulse (cumulative loading), of 19 patients with axial spondyloarthritis and 23 healthy controls during forward bending, sit-to-stand and two lifting tasks (symmetric/asymmetric). We compared inflammatory (n = 7) and ankylosed (n = 12) patients with axial spondyloarthritis and controls. Patients were also classified into Flexion or Lordotic profile.

Both inflammatory and ankylosed patients generated significantly larger lumbosacral moment impulses than healthy controls in all movements, except during sit-to-stand, where the inflammatory group showed larger moment impulse than both other two groups. Patients with a Lordotic profile showed lowered peak lumbosacral moments and moment impulses compared to those with a Flexion profile.

Both inflammatory and ankylosed patients experienced more cumulative loading depending on the activity. But our findings suggest that classification of patients into different movement profiles might be more interesting to clinically target specific loading adaptations related to pain and fear of movement.