Impact of Chair Seat Height on the 1-Minute Sit to Stand Test Performance in Chronic Obstructive Pulmonary Disease

The Impact of Chair Seat Height on the 1-Minute Sit to Stand Test Performance in Chronic Obstructive Pulmonary Disease: a Randomized Cross-over Study

The 1-minute sit to stand (1-min STS) test is a standardized test which is used to examine exercise capacity in patients with chronic obstructive pulmonary disease (COPD). The chair seat height used is standardized to 46-48 cm. Using a standard seat height for all patients - irrespective of their body height - may lead to invalid estimates of functional exercise capacity. The objective of this study is to assess whether there is a difference in repetitions during the 1-min STS test if the seat height is adjusted to 90° knee joint angle or the standard height chair of 46 cm is used.

In a single-center, randomized crossover study, the investigators aim to elucidate whether there is a difference in repetitions during the 1-min STS test if the seat height is adjusted to 90° knee joint angle or the standard height chair of 46 cm is used.

Patients with COPD referred for pulmonary rehabilitation will be invited to perform one standardised- (chair seat height 46cm) and one individualized (chair seat height adapted to 90° knee flexion) 1-min STS test on two different days in random order.

The tests will be performed after patients are familiarised with the 1-min STS testing procedure and learning effects can be excluded.

Inclusion Criteria:

• Patients with diagnosed COPD according to a forced expiratory volume in 1s (FEV1) / forced vital capacity (FVC) ratio below the lower limit of normal

Exclusion Criteria:

• Patients who are not able to bend their knees while sitting on a standard chair (i.e., knee flexion less than 90°)
• Patients who are not able to understand the instructions of the 1-min STS test, either of language or cognitive reasons
• Patients who are unable to perform the STS test due to functional disability (i.e., being not able to rise from a chair without hand support), previous surgery, or pain according to the judgement of the responsible physician.
• Patients who did not sign the informed consent form