Article Text

THU0605-HPR Patterns of Physical Activity Matter: Bout Analysis Reveals Differences Between Patients with Axial Spondyloarthritis and Healthy Controls
  1. T. Swinnen1,2,3,
  2. M. Milosevic4,
  3. T. Scheers5,
  4. J. Lefevre5,
  5. S. Van Huffel4,
  6. W. Dankaerts3,
  7. R. Westhovens1,2,
  8. K. de Vlam1,2
  1. 1Division of Rheumatology, University Hospitals Leuven
  2. 2Skeletal Biology and Engineering Research Center, Department of Development and Regeneration
  3. 3Research Group for Musculoskeletal Rehabilitation, Department of Rehabilitation Sciences
  4. 4Stadius Centre for Dynamical Systems, Signal Processing and Data Analytics, Department of Electrical Engineering
  5. 5Physical Activity, Sports & Health Research Group, Department of Biomedical Kinesiology, KU Leuven, Leuven, Belgium


Background Low total physical activity (PA) levels and remarkably less (very)vigorous physical activities have been shown in patients with axial spondyloarthritis (aSpA) compared to healthy controls using objective sensor-based technology1. Ten minute bouts of moderate to (very)vigorous PA (instead of frequent interruptions) are associated with additional health benefits. These within-day patterns of PA are unknown in aSpA.

Objectives To compare PA patterns (bouts) between patients with aSpA and healthy controls.

Methods PA was compared between 40 patients with aSpA (male/female: 24/16; Mean ± SD, Age:44.38±11.30 yrs, BMI:26.27±5.11 kg/m2, disease duration: 11.40±9.50 yrs) and 40 healthy, age and sex matched controls (Age:44.33±10.63 yrs, BMI:25.05±3.59 kg/m2) during five consecutive days (three weekdays and two weekend days) using the SenseWear Pro3 Armband. Weekly PA accumulated in 10-minute bouts (A) and the number of bouts (N) for each PA intensity level were contrasted between groups with Wilcoxon signed- rank tests (p<.05). Differences with prior non-bout (NB) data were provided for comparison with median group differences in %.

Results Weekly vigorous and very vigorous PA were significantly lower in aSpA irrespective of analysis technique (vigorous: NB: p<0.001,A&N: p=.003; very vigorous: NB p<001,A&N p=.008). Bouts analysis revealed novel and more profound (%) differences for moderate PA (NB: p=.070,-28%, A: p=.062,-49%, N:.046,-55%) and moderate to (very)vigorous PA (NB: p=.029,-32%, A: p=.003,-65%, N:p=.002,-67%) with lower values for patients. Thus in absolute terms, patients accumulate 21 minutes (trend) and two 10-minute bouts (significant) less moderate PA per day, a difference not detected with NB analysis. Similarly, patients performed 40 minutes and three 10-minute bouts less moderate to (very)vigorous PA. No differences between groups were found for inactivity and light PA (p>.05).

Conclusions Bout analysis revealed additional differences in health-enhancing PA behavior between patients with aSpA and healthy controls. This work adds to the emerging body of evidence showing lower PA in this patient group. Future work in aSpA should focus on the consequences of low PA, its relevance for outcome assessment and on the development of tailored PA interventions.


  1. Swinnen TW, Scheers T, Lefevre J, Dankaerts W, Westhovens R, de Vlam K. Physical activity assessment in patients with axial spondyloarthritis compared to healthy controls: a technology-based approach. PLoS One. 2014 Feb 28;9(2): e85309.

Disclosure of Interest None declared

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.