Movement-related skin strain associated with goal-oriented lip actions

Area of Science:

• Neuroscience
• Biomechanics
• Sensory Physiology

Background:

• Proprioception, the sense of body position, relies on sensory input.
• Most body parts have muscle spindles, tendon organs, and joint receptors for proprioception.
• The perioral area lacks these receptors, making it ideal for studying other sensory inputs.

Purpose of the Study:

• To investigate if skin strains in the lower lip contribute to facial proprioception.
• To determine the role of cutaneous mechanoreceptors in sensing lip movements.

Main Methods:

• Examined skin strains during lower-lip movements in human subjects.
• Measured the magnitude of skin strains and their relation to movement endpoints.
• Referenced human microneurographic studies on mechanoreceptor discharge.

Main Results:

• Skin strains during lower-lip movements are significant enough to activate cutaneous mechanoreceptors.
• The extent of multiple skin strains accurately predicted lower-lip movement endpoints.
• Cutaneous mechanoreceptors in the face may contribute to proprioception.

Conclusions:

• Cutaneous mechanoreceptors are likely important proprioceptors in the human face.
• Facial proprioception may rely on skin stretch rather than specialized proprioceptors.
• This study provides evidence for the role of skin sensation in facial motor control.