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Updated: Feb 4, 2026
Establishment of a Clinic-based Biorepository
Published on: May 29, 2017
Clinical Breathing Mechanics Differ Based on Test and Position
Context:
Altered diaphragm function is linked to decreased core stabilization, postural changes, and decreased function. Two clinical tests used to assess breathing are the Hi-lo and lateral rib expansion (LRE) tests. It is currently unknown how breathing classification based on these tests differ and how their results are affected by varying test positions.
Objective:
To compare the results of breathing tests when conducted in varying test positions.
Design:
Prospective cross-sectional study.
Setting:
University laboratory.
Participants:
A total of 50 healthy adults (females 31 and males 29; age 29.3 [4.1] y; height 170.0 [10.4] cm; weight70.7 [15.1] kg).
Intervention(S):
Hi-lo and LRE tests in supine, seated, standing, and half-kneeling body positions. All tests were recorded and later scored by a single examiner. A generalized estimating equations approach with breathing test and body position as factors was used for analysis. Pairwise comparison with Bonferroni correction was used to adjust for multiple tests. Statistical significance was set at P = .05, 2 tailed.
Main Outcome Measures:
Hi-lo and LRE tests were scored based on the presence or absence of abdominal excursion, LRE, and superior rib cage migration. Following scoring, results were classified as functional or dysfunctional based on observation of these criteria.
Results:
A significant breathing test × test position interaction (P < .01) was noted, as well as main effects for test (P < .01) and test position (P < .01). All Hi-lo test positions identified significantly more dysfunctional breathers in positions of increased stability demand (P < .01), except between standing and half-kneeling positions (P = .52). In the LRE test, all positions were similar (P > .99) except for half-kneeling, which was significantly different from all other positions (P < .01).
Conclusions:
The Hi-lo test and LRE tests assess different breathing mechanics. Clinicians should use these tests in combination to gain a comprehensive understanding of a person's breathing pattern. The Hi-lo test should be administered in multiple testing positions.
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