Longitudinal changes in ventral and dorsal neck muscle layers during loading against gravity in healthy volunteers using speckle tracking.
OBJECTIVE
This study aimed to describe and compare the longitudinal mechanical activity, deformation, and deformation rate of the different layers of dorsal and ventral neck muscles in healthy volunteers during head lifts against gravity.


METHODS
The cross-sectional study included 19 healthy volunteers (mean age, 28 years; SD, 7 years). Ultrasound with speckle-tracking analysis was used to investigate longitudinal mechanical activation, deformation, and deformation rate of dorsal and ventral neck muscles in real time during a head lift. Significance levels were set as P = .025 or P = .0125, depending on the number of comparisons.


RESULTS
The dorsal neck muscles did not significantly differ in deformation (P > .04); however, the multifidus had a higher deformation rate than all other dorsal muscles (P < .003). The sternocleidomastoid had significantly higher deformation than the longus capitis (P = .005) and colli (P = .001) but a lower deformation rate than the longus colli (P = .02).


CONCLUSIONS
The sternocleidomastoid deformed more than the deeper muscles, but it did significantly slower than the longus colli. Among the dorsal muscles, the deepest (the multifidus) had the highest deformation rate.
Associate Professor, NHMRC CCRE (Spinal Pain, Injury and Health), The University of Queensland, Brisbane, Australia; Associate Professor, Department of Medical and Health Sciences, Division of Physiotherapy, Faculty of Health Sciences, Linköping University, Linköping, Sweden. Electronic address: Anneli.Peolsson@liu.se.
Anneli
A
Peolsson
Doctor, Computational Life Science Cluster and Department of Chemistry, Umeå University, Umeå, Sweden.
Michael
M
Peolsson
D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D009334:Neck Muscles / Q000000981:diagnostic imaging* / Q000502:physiology; D016684:Prone Position / Q000502:physiology; D014463:Ultrasonography; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
Exercise; Motor Skills; Neck Muscles; Ultrasonography