Upper trunk flexion versus whole trunk elevation in semi-Fowler’s position: Effects on ventilation and heart rate responses

Sayuki Miyashita; Satoshi Kubota; Takuya Furudate

doi:10.2478/bhk-2026-0014

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Upper trunk flexion versus whole trunk elevation in semi-Fowler’s position: Effects on ventilation and heart rate responses

Biomedical Human Kinetics

Volume 18 (2026): Issue 1 (January 2026)

By: Sayuki Miyashita, Satoshi Kubota and Takuya Furudate

Open Access

|May 2026

Abstract

Study aim

The semi-Fowler’s position is widely used to support respiratory function and reduce cardiovascular stress. Despite the known cardiovascular benefits of upper trunk flexion in Fowler’s position, its effects in the semi-Fowler’s position remain uninvestigated. This study aimed to compare the effects of upper trunk flexion (UT30) and whole-trunk elevation (WT30) at 30° on ventilation and cardiac chronotropy in healthy young women.

Material and methods

Fourteen healthy young women (age: 20.6 ± 0.7 years; height: 162.1 ± 5.4 cm; weight: 53.1 ± 5.6 kg) participated in a randomized crossover design comparing supine, 30° whole-trunk elevation (WT30), and 30° upper trunk flexion at T10 (UT30). Tidal volume (TV), minute ventilation (MV), respiratory rate, and RR intervals were measured using a pneumotachograph and ECG (BIOPAC MP150) after 5-min equilibration. Data were analyzed using Linear Mixed Models (R version 4.3.3).

Results

Both UT30 and WT30 increased TV (Δ + 79 and + 94 mL) and MV (Δ + 0.89 and + 1.18 L/min) versus supine (all p < 0.001), with no UT30–WT30 differences. RR interval decreased in WT30 versus supine (Δ − 0.029 s, ≈ +2.1 bpm, p = 0.038) but not in UT30 (p > 0.05); the direct UT30–WT30 comparison was not significant.

Conclusions

These findings suggest that UT30 may be an efficient low-burden posture in healthy young women; applicability to populations with limited cardiovascular reserve requires direct clinical validation.

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Articles in this issue

DOI: https://doi.org/10.2478/bhk-2026-0014 | Journal eISSN: 2080-2234

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Language: English

Page range: 163 - 170

Submitted on: Jan 6, 2026

Accepted on: Apr 14, 2026

Published on: May 7, 2026

Published by: University of Physical Education in Warsaw

In partnership with: Paradigm Publishing Services

Publication frequency: 1 issue per year

Keywords:

Semi-Fowler’s Position,

Related subjects:

Basic medical science,

Basic medical science, other,

Clinical medicine,

Public health,

Sports and recreation,

Sports and recreation, other,

Physical education

© 2026 Sayuki Miyashita, Satoshi Kubota, Takuya Furudate, published by University of Physical Education in Warsaw
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 18 (2026): Issue 1 (January 2026)