Hi, my wife has numbness in her left leg below knee, she was sitting for a long period today... also she just put on evra contraceptive patch on.

Evra patch: Sitting for a prolonged period can compress blood vessels and sensory nerves to create "numbness". This should disappear as walking relieves the compression. The Evra patch contains both estrogen and progestins, and could increase the chance of having a blood clot in some deep veins. If the numbness does not stop, see a physician for an exam to be certain.