Studies in the past have revealed that postural orientations of the neck, such as flexed or forward head postures, are associated with heightened activity of the dorsal neck muscles. While these studies describe the impact of variations in neck posture alone, there is little literature dealing with the effect of neck posture on muscle activity when combined with upper limb activities such as lifting. The authors’ objective in this study was to examine the effect of three different neck postures on the activity of the different layers of the dorsal neck muscles during a lifting task. Ultrasound measurements of dorsal neck muscle deformation were compared over two time points (rest, during lift) during a lifting task performed in three different neck postural conditions (neutral, flexed and forward head posture) in 21 healthy subjects. They analysed the data with a post-process speckle tracking analysis. Their results showed significantly more muscle deformation induced by flexed and forward head postures, compared to the neutral posture, for all dorsal neck muscles at rest (p<0.05). Significant condition by time interactions associated with the lift was observed for four out of the five dorsal muscles (p<0.02).
Their findings demonstrated that posture of the cervical spine influenced the level of muscle deformation at rest as well as when lifting. They conclude that their findings indicate that neck posture should be taken in to account during the evaluation or design of lifting activities as it may add to excessive demands on dorsal neck muscles with potentially detrimental consequences.