Effect of Dynamic Sitting on Pain Development - Part 2

This clinical trial is a prospective, randomised, controlled, open-label study with two tracks, each in a cross-over design investigating the effect of of two dynamic office chairs (saddle chair with standard pendulum mechanism [Smart Moving Technology], study track 2 = office swivel chair with integrated newly developed pendulum mechanism [Smart Moving Technology New]) on the musculoskeletal system of office workers classified as pain developers.

The study consists of a pre-screening visit and 4 assessment days / visits. After proving eligibility for the study (inclusion/exclusion criteria), subjects are assigned to one of the two study tracks. Subjects are randomised to one of the two study tracks and then to the respective group (Group A to D).

• Study track 1: saddle chair with standard pendulum mechanism (= intervention 1) + static office chair (= control)
• Study track 2: office swivel chair with integrated newly developed pendulum mechanism (= intervention 2) + static office chair (= control).

Depending on the study track and group allocation, the test subjects first receive a dynamic office chair (= intervention) or a static office chair (= control). The randomization will be realized with opaque envelopes in different colours and follows international recommendations.

Overall participants will execute identical assessments. A wash-put period between the control and the intervention phases ensures identical baseline conditions. The overall duration of study participation equals 16 weeks.

Inclusion criteria

• Signed Informed consent
• People aged between 18 and 65 years
• People classified as pain developers (e.g.: a 10 mm increase in pain on a 100 mm paper-based VAS)
• Office workers
• Employment status: > 25 h / week
• Sufficient knowledge of German (min. B2 level)
• Body height of at least 160cm required
• Electrically or manually height-adjustable table at main workstation

Exclusion criteria

• Physical or mental limitations that make dynamic sitting or use of the procedure chair difficult (e.g. wheelchair users, vestibular dysfunction)
• Pregnancy
• Sitting for less than 20 hours per week at the main workplace
• Body weight over 110 kg and a body height over 195 cm
• Regular therapy or medication for pain or medication that affects the perception of pain (e.g. certain psychotropic drugs according to the package leaflet)
• office chair to which it is not possible to attach the swivel mechanism prototype
• Presence of any chronic disease that may influence pain perception (e.g., chronic kidney disease, fibromyalgia, neuropathy, chronic fatigue syndrome)