Optoelectronic Plethysmography Characterises Thoracic Excursion In The Evaluation Of Dysfunctional Breathing (DB)

Abstract

PURPOSE: Ventilatory pattern and thoracic excursion, can vary during exercise and impact on ventilatory performance. A deviation away from an optimal trunk lumbo-pelvic recruitment pattern may affect lung volumes, work of breathing and may be relevant in the development of exertional dyspnoea. The aim of the study was to investigate the effect of different postural positions on the ventilatory excursion using optoelectronic plethysmography (OEP) and a spirometer. METHODS: Fifteen healthy male athletes (Mean ± SD age: 30.3±6.5 yrs.) completed the study. Ninety reflective markers were placed on the chest, abdomen and back (Figure 1). Participants underwent simultaneous OEP and spirometry data collection in two conditions, in a randomised order: (C1) with normal shoulder position or (C2) with hunched shoulders. Forced vital capacity (FVC) was assessed by the spirometer and data was gathered on the chest wall volume (CW) and the compartmental volumes of the rib cage (RC) and the abdomen (AB) by OEP. RESULTS: The correlation between the two instruments in measuring FVC was good in both normal (R2=0.89) and hunched (R2=0.84) positions. FVC was significantly lower in hunched position during both spirometry (5.22±0.69 L vs. 5.35±0.69 L; p=0.03) and OEP measurements (5.22±0.62 L vs. 5.42±0.69 L; p=0.01). When volume contributions in the two conditions were compared the RC/AB ratio was significantly lower in hunched position (1.84±0.74 vs. 2.12±0.79; p=0.01). CONCLUSIONS: These findings suggest that respiratory excursion and lung volume compartmentalisation are affected by the position of the shoulders. Specifically, a hunched should position leads to increased abdominal motion to vital capacity and decreased lung volumes. OEP may be a useful tool to detect altered parameters associated with developement of exertional dyspnoea.Figure