Effects of Diaphragmatic Breathing Exercise on Respiratory Functions and Vocal Sustenance in Apparently Healthy Vocalists Author: Sylvester Caesar Chukwu1, Chukwuenyegom Joseph Egbumike2, Chidiebele P Ojukwu1, Chigozie Uchenwoke1, Emeka S Igwe1, Nkechi R Ativie1, Adaora J Okemmuo1, Nkem P Chukwu1, Uchechukwu A Ezeugwu1, Chioma N Ikele1, Ekezie M Uduonu1 Affiliation: <sup>1</sup> Department of Medical Rehabilitation, University of Nigeria, Nsukka, Enugu State, Nigeria. <sup>2</sup> Department of Medical Rehabilitation, University of Nigeria, Nsukka, Enugu State, Nigeria; Department of Physiotherapy, Evangel University, Akaeze, Ebonyi State, Nigeria. Electronic address: eegbumike@gmail.com. Conference/Journal: J Voice Date published: 2022 Nov 1 Other: Special Notes: doi: 10.1016/j.jvoice.2022.09.025. , Word Count: 316 Background: Effective vocalization is dependent on breathing efficiency. Previous studies have reported the efficacy of Diaphragmatic Breathing Exercise (DBE) on the respiratory muscles and breath control of vocalists. There is a paucity of data on the effects of DBE on their vocal sustenance (VS), which is determined as Maximum Phonation Time (MPT). No known published study has considered physiotherapy as influencing voice dynamics amongst vocalists; evaluated the relationship between respiratory functions (Forced Vital Capacity - FVC, Forced Expiratory Volume in one second - FEV1, FEV1/FVC, and Peak Expiratory Flow - PEF) and VS in apparently healthy vocalists. Moreover, literature on the benefits of DBE to vocalists has not considered explicitly this aspect of vocalization skill, VS. Methods: This is a pre-test - post-test experimental study involving a total of 37 participants (17 males and 20 females) selected by purposive and convenience sampling techniques. The subjects were grouped into DBE and control groups. Spirobank MIR spirometer was used to assess the respiratory function of the singers, while a stopwatch and keyboard were used in assessing the MPT. Statistical analysis was done with SPSS version 21.0. Alpha level set at 0.05. Results: Significant improvement was found in respiratory functions (FVC, FEV1, FEV1/FVC, PEF) of the DBE group when pre- and post-test results were compared. The DBE and control groups differed significantly. Respiratory values correlated significantly with the MPT values (FVC - r[p] - 0.416[0.011]; FEV1 - r[p] - 0.416[0.010]; PEF - r[p] - 0.566[0.000]), except for FEV1/FVC - r(p) - 0.248(0.138). Voice category did not correlate with respiratory parameters or MPT. While male singers showed more changes in respiratory function the female singers showed more improvement in MPT. Conclusion and recommendation: DBE can improve respiration and VS (increased MPT). Therefore, it can be recommended for vocalists, and Physiotherapy can be relevant in trainings to improve vocal dynamics. Keywords: Respiratory function—Deep breathing exercise—Singers—Physiotherapy—Voice. PMID: 36333216 DOI: 10.1016/j.jvoice.2022.09.025