In:
Medicine & Science in Sports & Exercise, Ovid Technologies (Wolters Kluwer Health), Vol. 52, No. 7 ( 2020-7), p. 1610-1616
Abstract:
This study aimed to compare muscle activation of the diaphragm (DIA), scalenes (SA), parasternal intercostals (PS), and sternomastoid (SM) during submaximal intermittent neck flexion (INF) versus submaximal inspiratory threshold loading (ITL) until task failure in healthy adults. Methods Twelve healthy adults performed submaximal ITL or INF tests in random order for 2 d. Surface electromyography was monitored to acquire root mean square (RMS) and median power frequency (MPF) from the SA, PS, SM, and DIA. Maximal inspiratory pressures and maximal voluntary contraction for neck flexion were determined. Next, participants performed the first submaximal test—ITL or INF—targeting 50% ± 5% of the maximal inspiratory pressure or maximal voluntary contraction, respectively, until task failure. After a rest, they performed the other test until task failure. Two days later, they performed ITL and INF but in the opposite order. The Borg scale assessed breathlessness and perceived exertion. Results Endurance times for ITL and INF were 38.1 and 26.3 min, respectively. INF activated three of four inspiratory muscles at higher average RMS (PS, SM, and SA) and at different MPF (PS, SM, and DIA but not SA) compared with ITL. During ITL, RMS did not change in the four inspiratory muscles over time, but MPF decreased in PS, SM, and SA ( P 〈 0.04). In contrast, RMS increased in three of four inspiratory muscles (SM, PS, and SA) during INF, but MPF did not change throughout its duration. Borg rating was 3.9-fold greater than ITL compared with INF. Conclusion At a similar percentage of maximal load, INF evokes greater activation of primary muscles of inspiration (PS and SA) and a major accessory muscle of inspiration (SM) compared with ITL during a prolonged submaximal protocol.
Type of Medium:
Online Resource
ISSN:
1530-0315
,
0195-9131
DOI:
10.1249/MSS.0000000000002271
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2020
detail.hit.zdb_id:
2031167-9
SSG:
31
