The purpose of this study was to examine scalene (SA) and sternocleidomastoid (SM) activation during normoxic (norm-ITL; FIO = 21%) and hypoxic (hyp-ITL; FIO = 15%) incremental inspiratory threshold loading (ITL). Thirteen healthy participants (33 ± 4 years, 9 female) performed two ITL tests breathing randomly assigned gas mixtures through an inspiratory loading device where the load was increased every two minutes until task failure. SA and SM root mean square (RMS) electromyography (EMG) were calculated and expressed as a percentage of maximum (RMS ) to reflect muscle activation intensity. Myoelectric manifestations of fatigue were characterized as decreased SA or SM EMG median frequency during maximum inspiratory pressure maneuvers before and after ITL. Dyspnea was recorded at baseline and task failure. Ventilatory parameters and mouth pressure (Pm) were recorded throughout the ITL. SA,RMS and SM,RMS increased in association with ITL load (p ≤ .01 for both). SA,RMS was similar between norm-ITL and hyp-ITL (p = .17), whereas SM,RMS was greater during the latter (p = .001). Neither SA nor SM had a decrease in EMG median frequency after ITL (p = .75 and 0.69 respectively). Pm increased in association with ITL load (p < .001) and tended to be higher during hyp-ITL compared to norm-ITL (p = .05). Dyspnea was similar during both conditions (p > .05). There was a trend for higher tidal volumes during hyp-ITL compared to norm-ITL (p = .10). Minute ventilation was similar between both conditions (p = .23). RMS, of the SA and SM increased linearly with increasing ITL. The presence of hypoxia only increased SM activation. Neither SA nor SM presented myoelectric manifestations of fatigue during both conditions.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7389984 | PMC |
| http://dx.doi.org/10.14814/phy2.14522 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Inspiratory effort and respiratory muscle activation during different breathing conditions in patients with weaning difficulties: An exploratory study.
Aust Crit Care
January 2025
KU Leuven, Department of Rehabilitation Sciences, Research Group for Rehabilitation in Internal Disorders, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of Intensive Care Medicine, Leuven, Belgium.
Background: Recent studies suggest that fast and deep inspirations against either low or high external loads may provide patients with weaning difficulties with a training stimulus during inspiratory muscle training (IMT). However, the relationship between external IMT load, reflected by changes in airway pressure swings (ΔPaw), and total inspiratory effort, measured by oesophageal pressure swings (ΔPes), remains unexplored. Additionally, the association between ΔPes, ΔPaw, and inspiratory muscle activations remains unclear.
View Article and Find Full Text PDFMethods to normalize surface electromyography in respiratory muscles: Is it similar between amyotrophic lateral sclerosis and healthy people?
PLoS One
December 2024
PneumoCardioVascular Lab/Hospital Universitário Onofre Lopes (HUOL), Empresa Brasileira de Serviços Hospitalares (EBSERH), Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
Article Synopsis
- The study focuses on comparing methods for normalizing electromyographic signals from respiratory muscles in both healthy individuals and those with Amyotrophic Lateral Sclerosis (ALS).
- 67 subjects (50 healthy and 17 with ALS) were analyzed during various breathing maneuvers to measure muscle activity.
- The results indicated that for healthy individuals, maximal voluntary isometric contraction (MVIC) was the best method for assessing inspiratory muscle activity, while in ALS patients, the maximum nasal inspiratory pressure (SNIP) maneuver was more effective for inspiratory muscle normalization.
Article Synopsis
- The posterior cervical triangle is crucial for understanding the spread of head and neck cancers, particularly skin cancers of the scalp, and requires a thorough knowledge of the neurovascular structures there.
- Traditional 2D anatomical diagrams don't effectively convey the important spatial relationships needed for successful surgery, prompting the creation of a 3D virtual model.
- This study involved segmenting musculature and neurovasculature from a CT scan and reviewing literature to yield an anatomically accurate 3D model, which will be available online for educational purposes.
Benefits of chest wall mobilization on respiratory efficiency and functional exercise capacity in people with severe chronic obstructive pulmonary disease (COPD): A randomized controlled trial.
Respirology
September 2024
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, Hong Kong.
Article Synopsis
- The study explored how chest wall mobilization affects exercise capacity and respiratory muscle function in men with severe COPD.
- Participants (30 males, average age 75) were divided into a chest wall mobilization group and a control group, both receiving exercise education, but only the CWMG received additional mobilization treatments.
- Results showed that the CWMG had significantly improved exercise tolerance, reduced muscle activity during tests, and maintained these benefits three months after the program, highlighting the potential advantages of chest wall mobilization in COPD rehabilitation.
Prevalence of Myofascial Trigger Points in Isolated Idiopathic Cervical Dystonia: A Possible Contributor to Pain, Movement and Disability.
Mov Disord Clin Pract
September 2024
Department of Medicine, School of Medicine, Universidad Complutense, Madrid, Spain.
Article Synopsis
- Myofascial trigger points (TrPs) are sensitive spots in muscles that cause both local and referred pain; this study explores their role in patients with cervical dystonia (CD).
- A total of 31 participants were assessed for TrPs in specific neck and shoulder muscles, and pain levels were documented using the Toronto Western Spasmodic Torticollis Rating Scale.
- The study found that only patients with pain had active TrPs, while all patients had latent TrPs, suggesting that active TrPs may contribute to pain and disability in CD.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!