Lie on your back with the leg you want to exercise straight. The other knee should be bent to support your lower back. Tighten the muscle on the top of your thigh and lift to the level of your other knee. Slowly lower.
While it was originally believed that most vascular malformations are present at birth (congential), cavernous malformation lesions may develop throughout the lifetime of the affected individual. Other vascular malformations are not congenital, but are caused by trauma, radiation, or other injury to the spinal cord.
See also: Cerebral arteriovenous malformation. Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system (usually cerebral AVM), but can appear in any location.