Method for determining facial muscle responses

A method for quantitatively assessing muscle contraction of a facial muscle in a person and determining the ability of a treatment material to reduce contraction of the facial muscle, the method comprising:

• (a) applying an external electrical stimulus to facial skin sufficient to contract a facial muscle, wherein the external electrical stimulus is applied at an interval for 1 to 10 seconds and/or is applied for 2 to 20 intervals;
• and
• (b) measuring the contractile activity of the contracted facial muscle by measuring the compound motor action potential (CMAP) of the contracted facial muscle to obtain a first average measurement of contractile activity of the contracted facial muscle;
• and then
• (c) administering the treatment material by topically applying the treatment material to the facial skin;
• and
• (d) repeating steps (a) and (b) to obtain a second average measurement of contractile activity of the contracted facial muscle,
• wherein a decrease in contractile activity based on the second average measurement as compared to the first average measurement indicates that the treatment material reduces contraction of the facial muscle when administered to the facial skin.