Intermittent neck flexion induces greater sternocleidomastoid deoxygenation than inspiratory threshold loading

© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature..

PURPOSE: To compare deoxygenation of the sternocleidomastoid, scalenes, and diaphragm/intercostals (Dia/IC) during submaximal intermittent neck flexion (INF) versus submaximal inspiratory threshold loading (ITL) in healthy adults.

METHODS: Fourteen participants performed a randomized, cross-over, repeated measures design. After evaluation of maximal inspiratory pressures (MIP) and maximum voluntary contraction (MVC) for isometric neck flexion, participants were randomly assigned to submaximal ITL or INF until task failure. At least 2 days later, they performed the submaximal exercises in the opposite order. ITL or INF targeted 50 ± 5% of the MIP or MVC, respectively, until task failure. Near-infrared spectroscopy (NIRS) was applied to evaluate changes of deoxy-hemoglobin (ΔHHb), oxy-hemoglobin (ΔO2Hb), total hemoglobin (ΔtHb), and tissue saturation of oxygen (StO2) of the sternocleidomastoid, scalenes, and Dia/IC. Breathlessness and perceived exertion were evaluated using Borg scales.

RESULTS: Initially during INF, sternocleidomastoid HHb slope was greatest compared to the scalenes and Dia/IC. At isotime (6.5-7 min), ΔtHb (a marker of blood volume) and ΔO2Hb of the sternocleidomastoid were higher during INF than ITL. Sternocleidomastoid HHb, O2Hb, and tHb during INF also increased at quartile and task failure timepoints. In contrast, scalene ΔO2Hb was higher during ITL than INF at isotime. Further, Dia/IC O2Hb and tHb increased during ITL at the third quartile and at task failure. Borg scores were lower at task failure during INF compared to ITL.

CONCLUSION: Intermittent INF induces significant metabolic activity of the sternocleidomastoid and a lower perception of effort, which may provide an alternative inspiratory muscle training approach for mechanically ventilated patients.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:124

Enthalten in:

European journal of applied physiology - 124(2024), 4 vom: 02. Apr., Seite 1151-1161

Sprache:

Englisch

Beteiligte Personen:

Miles, Melissa [VerfasserIn]
Davenport, Paul [VerfasserIn]
Mathur, Sunita [VerfasserIn]
Goligher, Ewan C [VerfasserIn]
Rozenberg, Dmitry [VerfasserIn]
Reid, W Darlene [VerfasserIn]

Links:

Volltext

Themen:

Exercise
Fatigue
Hemoglobins
Journal Article
Near infrared
Oxygen
Oxyhemoglobins
Randomized Controlled Trial
Respiratory muscles
S88TT14065
Spectroscopy

Anmerkungen:

Date Completed 22.03.2024

Date Revised 02.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s00421-023-05338-6

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM364157372