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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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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

Conditions
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COPD, Chronic Obstructive Pulmonary Disease

Intervention / Treatment
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* Other: 1-min STS test: adjusted
* Other: 1-min STS test: standardized


Participation Criteria
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Eligibility Criteria
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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
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1-min STS test: chair seat height adjusted to 90° knee flexion<br>In this experimental condition, the patient performs the 1-minute sit to stand test on an individually adjusted seat height of 90° knee joint flexion. | Other: 1-min STS test: adjusted<br>* Individually adjusted chair seat height of 90° knee joint flexion<br>|
| Active Comparator: 1-min STS test: chair seat height standardized of 46cm<br>In this experimental condition, the patient performs the 1-minute sit to stand test on a standard height chair of 46cm. | Other: 1-min STS test: standardized<br>* Standardized chair seat height of 46 cm<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of repetitions in the 1-min STS test | difference in the amount of sit to stand repetitions in the 1-min STS test from a standard chair (46cm) or an individualized seat height chair of 90° knee joint angle | During pulmonary rehabilitation, approximately 14 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sit to stand power index | The sit to stand power index is used to calculate the force-generating capacity (in watt) of the knee extensor muscles and is defined as: (leg length (in m) - seat height (in m)) x body mass x acceleration of gravity x sit to stand repetitions / time (sit-stand) (in sec.) | During pulmonary rehabilitation, approximately 14 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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1-minute Sit to Stand Test, chair seat height