あぐら座位が咳嗽力に与える影響

あぐら座位は，和式生活に特徴的な座位姿勢で，床上での食事動作中に選択することがある。食事動作中は，誤嚥リスクが高まることが予測されるため，咳嗽力を維持することは重要である。以上のことから，あぐら座位が咳嗽力に与える影響を検討した。健常若年男性 13 名に対し，あぐら座位と端座位において，咳のピークフロー（Cough Peak Flow：CPF），努力性肺活量（Forced Vital Capacity：FVC），最大吸気口腔内圧（Maximal Inspiratory Mouth Pressure：PImax），最大呼気口腔内圧（Maximal Expiratory Mouth Pressure：PEmax）を測定した。CPF，FVC， PImax はあぐら座位で有意に低値を示した（P=0.029，P=0.043，P=0.024）。PEmax は，あぐら座位と端座位の間に有意差を認めなかった（P=0.098）。また，あぐら座位で CPF と FVC， PImax の間に有意な正の相関関係を示す傾向がみられた。あぐら座位では，姿勢の変化の影響を受け，肺気量，呼吸筋力が低下し，結果的に咳嗽力が低下したため，特に食事動作中，あぐら座位を避けることで，咳嗽力や各呼吸機能を維持できる可能性が考えられた。

The cross-legged position is the standard traditional sitting position in the Japanese lifestyle. It is common for people to sit cross-legged on the floor while having a meal. Considering that the risk of aspiration is high while having a meal, it is important to maintain cough capacity to prevent aspiration. In this study, we examined the effect of the cross-legged sitting position on cough capacity. Thirteen healthy young men participated in the study. The cough peak flow (CPF), forced vital capacity (FVC), maximum inspiratory mouth pressure (PImax), and maximum expiratory mouth pressure (PEmax) were measured in the cross-legged sitting position as well as in the chair sitting position without a backrest. CPF and FVC, indicators of lung volume, were measured using an electronic spirometer. PImax and PE max, indicators of respiratory muscle strength, were assessed using a measurement device connected to the electronic spirometer. The CPF, FVC, PImax, and PEmax of cross-legged sitting position were compared with those of the chair sitting position using a paired t test. The values of CPF, FVC, and PImax were significantly lower in the cross-legged sitting position than those in the other sitting positions (P=0.029, P=0.043, P=0.024, respectively). PEmax values were not significantly different, in the cross-legged sitting position than those in the chair sitting position (P=0.098). In addition, CPF showed some positive correlation with FVC and PImax in cross-legged sitting position. To conclude, in the cross-legged sitting position, the lung volume and respiratory muscle strength were found to be reduced, resulting in a decrease in the cough capacity. Based on the above findings, we recommend not to sit cross-legged during meals so as to maintain cough capacity.