Material and methods
pre-diagnosed, fatty meals, pain
RESPIRATORY TRACT INFECTION, REGRESSION, SECONDARY, STS
Healthy participants aged 18 years and older were deemed eligible for this study. We excluded all participants who had a pre-diagnosed clinical condition, experienced a respiratory tract infection within the last 2 weeks, were either current or previous smokers who quit less than 1 year ago, and were unable to perform or had pain during the STS manoeuvres. All participants were advised to refrain from vigorous physical activities for at least 24 h before the study procedure. In addition, they were requested to not ingest fatty meals and caffeine for at least four hours before the commencement of the study procedure.We performed a randomised crossover study at the Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland. Participants attended a single study visit and were randomly assigned to the experimental sequence (i.e., either performing a 1MSTST from standard seat height first or performing a 1MSTST from individualised seat height first) by computerised randomisation.We conducted this study in accordance with the Declaration of Helsinki (The study is reported in accordance with the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement: extension to randomised crossover trials (Dwan et al. The standardised 1MSTST was conducted following published protocols (Radtke et al. The individualised 1MSTST was performed according to the same protocol and instruction guide as the standardised 1MSTST. However, we adjusted seat height to ensure a knee flexion angle of 90° was present in the starting position. We aimed to elicit maximal performance in each participant and therefore did not restrict ankle dorsiflexion. Instead, we applied the following procedure: (i) adjusting seat height, (ii) participant performed three trial repetitions aiming to position their feet at the subjectively best position, (iii) readjustment of seat height if required.During the experimental day, both modalities of the 1MSTST were measured twice, controlling for a possible learning effect (Radtke et al. Experimental day. Participants attended a single experimental day and were randomly assigned to the sequence of tests (i.e., the order of Period 1 and Period 2). The standardised 1MSTST was done on a standard chair with seat height 46 cm; the individualised 1MSTST was done from a seat height adjusted to a knee flexion angle of 90° in the starting position. The primary outcome of this investigation was the number of repetitions in the 1MSTST. As secondary endpoints, we collected data on the acute physiological response to the 1MSTSTs; SpORegarding demographical and morphological variables, we measured body weight, body height, femur length, and tibia length. Two blinded assessors quantified femur and tibia length and the mean value of these measurements was used for analysis. Tibia and femur length were measured by tape measure in a supine, relaxed position. To evaluate tibia length, the lateral knee joint gap and the lower edge of the malleolus lateralis were used as landmarks. Whereas femur length was measured using the trochanter major and the lateral knee joint gap as landmarks.To ensure all participants were able to perform at their maximal capacity, we asked them to rate their current health status on the Feeling Thermometer from 0 (worst possible status) to 100 (perfect health) before beginning with the experiment (Munro et al. All results are shown as mean (SD) unless stated otherwise, the distribution of the variables was determined visually using quantile–quantile plots. A two-sided p value < 0.05 was considered statistically significant.We analysed the effect of the 1MSTST modality on the number of repetitions (i.e., the primary outcome) using linear mixed regression modelling with random intercepts. We adjusted for carry-over and period effects. Regarding the dependent variable, we proceeded with the try in each modality that elicited the highest number of repetitions. To estimate the influence of morphology (i.e., length of femur and tibia), we applied the stepwise backward elimination procedure to linear mixed regression modelling with interaction terms and random intercept.Regarding the analysis of the secondary outcomes, we used descriptive statistics. The acute responses to each modality were described by calculating the differences in SpOOur sample size determination was based on the evidence that regression modelling requires at least 10 participants per independent variable included in the final model (Harrell All analyses were performed with R version 4.0.3 for Windows (R Core Team 2022, R Foundation for Statistical Computing, Vienna, Australia).