"If you want your spouse to listen and pay strict attention to every word you say, talk in your sleep."
Anonymous
Periodic Limb Movement Disorder or PLMD is a disorder where the sufferer involenterely moves his or her limbs PLMS can cause insomnia and daytime sleepiness. The incidence of this disorder increases with age. It is estimated to occur in 5% of people age 30 to 50 and in 44% of people over the age of 65
source: http://en.wikipedia.org/wiki/Periodic_limb_movement_disorder
Periodic Limb Movements In Sleep
Infomation on PLMD in sleep
Sleep Disorders and Leg Movement
The experiences of sleeping leg movements