Article

Objective: To evaluate the capacity of the ultrasound-based method of speckle
tracking analysis to detect changes in multilayered dorsal neck muscle activity
induced by performing a lifting task. Subjects: Twenty-one healthy individuals.
Design: Participants performed a loaded lifting task in 3 different postural
orientations of the neck (neutral, flexed and forward head posture). Ultrasound
images were recorded and speckle tracking analysis was used to quantify muscle
deformation and deformation rate over 3 equal time-periods during the lifting
sequence (rest, mid-lift and end-lift). Results: Significant main effects of
postural orientation for the deformation measure (p < 0.05) and time for the
deformation rate measure (p < 0.05) were observed in all dorsal muscles examined.
Significant time by postural interactions for the deformation measure were
observed in the trapezius, semispinalis cervicis and multifidus (p < 0.05) and in
the semispinalis cervicis (p < 0.05) for the deformation rate measure.
Conclusion: Speckle tracking analysis ultrasound measurements can detect
differences in multilayered muscle activity of the dorsal neck induced by
postural variations during a lifting task. Findings for the deformation and the
deformation rate measures suggest that they quantify a different, albeit related,
mechanical event during muscle contraction in a functional task such as lifting.

Langue : ANGLAIS