You could have Periodic Limb Movement Disorder, which would manifest as rythmic movements during sleep. Also, sometimes people with sleep apnea will experience body movements with the apnea events. Sounds like you could benefit from an overnight sleep study to evaluate the cause and how much your movements are disrupting your sleep stages and to determine whether you need treatment or not.
nocturnal myoclonus or periodic limb movement disorder (PLMD) is a sleep disorder characterized by rhythmic movements of the limbs during sleep. Symptoms of PLMD are usually leg movements with the extension of the big toe in combination with a partial flexing of the ankle, knee or hip. The causes of PLMD are unknown and patients are frequently unaware of these movements.It may occur with other sleep disorders and is related to, but not synonymous with, restless leg syndrome (RLS) Diagnosis is made on an overnight polysomnogram. Blood work may be done in order to test iron status, folic acid, vitamin B12, thyroid function and magnesium levels.
Caffeine and alcohol can bring on severe limb movement during sleep and should be avoided. Improved sleep hygiene is also an effective treatment which includes: exercise regularly, get enough sleep, and reducing stress levels. The best way to prevent the onset of the symptoms and complications of PLMD is for the sufferer to work with their doctor, so that the causes can be treated, removed, or reduced. This link may be helpful: http://www.emedicine.com/neuro/TOPIC523.HTM
Take care and keep us posted.