Tics are rapid, repetitive, involuntary contractions of a group of muscles that can be mild and infrequent or frequent and severe, as in the case of your daughter's cough.

Firstly the group of muscles required to purse the lips run through the upper lip.

For instance, the control of a group of muscles leads to a better pronunciation of a word or performance of a piece of music.

The most common causes are the overuse or over-stretching of a muscle or group of muscles.

Muscles are normally arranged in opposition so that as one group of muscles contract, another group relaxes or lengthens.