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

BACKGROUND: 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. METHODS: 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. FINDINGS: 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. INTERPRETATION: 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.

Differences in multi-segmental spine kinematics between patients with different stages of axial spondyloarthritis and healthy controls.

BACKGROUND: The effects of inflammation and ankylosis on spinal kinematics of patients with axial spondyloarthritis (axSpA) are poorly understood. Furthermore, existence of (mal)adaptive movement profiles within axSpA, and differences between movement profiles in sensation of pain or fear of movement has never been investigated. OBJECTIVES: To investigate differences in range of motion in six spinal regions and the hips between inflammatory and ankylosed patients with axSpA, and to increase insight in different movement profiles of patients with axSpA and their association with pain and fear. DESIGN: Observational, cross-sectional. METHODS: Three-dimensional motion analysis was performed in 20 patients with axSpA and 23 healthy controls during range of motion tasks in all three planes. We compared patients with inflammatory (n = 8) and ankylosed (n = 12) axSpA, and controls. Patients were also classified into Flexion or Lordotic profile. Questionnaires regarding pain and fear of movement were conducted. RESULTS/FINDINGS: Both inflammatory and ankylosed axSpA patients have limited spinal ROM and reduced movement speed compared to healthy controls. Patients with a Lordotic profile showed significantly less ROM in lumbar regions and experienced more pain during forward bending than patients with a Flexion profile. CONCLUSIONS: Both inflammation and ankylosis contribute to spinal mobility impairment, and axSpA patients with a lordotic profile experienced more pain. This profile may be a maladaptive movement strategy to prevent further pain increase. Suggesting that pain and fear of movement, might be better variables to specify patients' spinal mobility limitations for individual physical therapy and rehabilitation patient profiling.

Inter-segmental coordination of the spine is altered during lifting in patients with ankylosing spondylitis: A cross-sectional study.

The abnormal inter-segmental coordination of the spine during lifting could be used to monitor disease progression and rehabilitation efficacy in patients with ankylosing spondylitis (AS). This study aimed to compare the inter-segmental coordination patterns and variability of the spine during lifting between patients with AS (n = 9) and control (n = 15) groups.Continuous relative (CRP) and deviation (DP) phases between each segment of the spine (two lumbar and three thorax segments) and lumbosacral joint were calculated. The CRP and DP curves among participants were decomposed into few functional principal components (FPC) via functional principal component analysis (FPCA). The FPC score of CRP or DP of the two groups were compared, and its relationship with the indexes of spinal mobility was investigated.Compared with the control group, the AS patients showed more anti-phase coordination patterns in each relative upper spine segment and lumbosacral joint. In addition, either less or more variation was found in the coordination of each relative lower spine segment and lumbosacral joint during different time periods of lifting for these patients. Some cases were considerably related to spinal mobility.the inter-segmental coordination of the spine was altered during lifting in AS patients to enable movement, albeit inefficient and might cause spinal mobility impairment.

Multi-segment spine and hip kinematics in asymptomatic individuals during standardized return from forward bending versus functional box lifting.

Clinically, sagittal spinal mobility is objectively assessed by forward bending range of motion (ROM) tests such as the modified-Schober test (m-Schober test). However, evidence comparing ROM during forward bending and daily activities is limited. In this study, a kinematic model including six spinal regions, pelvic/sacral and femur segment was used to characterize associations between m-Schober test and return from forward bending (RFB), and between RFB and lifting. No significant correlations were found between m-Schober test and lumbar ROM during RFB. Furthermore, we found significantly smaller ROM in all spinal regions during lifting compared to RFB, except in the upper thoracic spine, lumbosacral (L5/S1) and hip joints. However, we observed moderate to very strong correlations between the two movements tasks for all lumbar regions. Furthermore, cross-correlation between L5/S1 and lower lumbar spine regions showed no segmental redundancy of L5. These results suggest that an m-Schober test provides insufficient insight into lumbar mobility and that multi-segmental spine measurements should be introduced clinically. Furthermore, this study has demonstrated that RFB can be used as a reference for lumbar regions during lifting, with use of the current multi-segmental spine model and that the inclusion of L5/S1 provides more detailed information on lumbar kinematics.

Influence of outdoor running fatigue and medial tibial stress syndrome on accelerometer-based loading and stability.

Medial tibial stress syndrome (MTSS) is a common overuse running injury with pathomechanics likely to be exaggerated by fatigue. Wearable accelerometry provides a novel alternative to assess biomechanical parameters continuously while running in more ecologically valid settings. The purpose of this study was to determine the influence of outdoor running fatigue and MTSS on both dynamic loading and dynamic stability derived from trunk and tibial accelerometery. Runners with (n=14) and without (n=16) history of MTSS performed an outdoor fatigue run of 3200m. Accelerometer-based measures averaged per lap included dynamic loading of the trunk and tibia (i.e. axial peak positive acceleration, signal power magnitude, and shock attenuation) as well as dynamic trunk stability (i.e. tri-axial root mean square ratio, step and stride regularity, and sample entropy). Regression coefficients from generalised estimating equations were used to evaluate group by fatigue interactions. No evidence could be found for dynamic loading being higher with fatigue in runners with MTSS history (all measures p>0.05). One significant group by running fatigue interaction effect was detected for dynamic stability. Specifically, in MTSS only, decreases mediolateral sample entropy i.e. loss of complexity was associated with running fatigue (p<0.01). The current results indicate that entire acceleration waveform signals reflecting mediolateral trunk control is related to MTSS history, a compensation that went undetected in the non-fatigued running state. We suggest that a practical outdoor running fatigue protocol that concurrently captures trunk accelerometry-based movement complexity warrants further prospective investigation as an in-situ screening tool for MTSS individuals.