Sharp Pain In Triceps When Stretched. Numbness In Area When Rubbed. No Injury To That Area. Reason?

I have a weird sharp pain that happens in my tricep when I stretch it. The pain isnt really that bad but it is a very quick and sharp jolt of sensitivity in the mid (between shoulder and elbow level)to lower tricep area (nearer to the elbow). No idea what caused this. It just happens when I go from straight arm position to fully bent elbow position. The initial sensation is a sharp jolt, but after that, its just a tight feeling in that area with only a bit of pain. I mostly feel it when I put my hand down on something while my elbow is bent outward, and then I move my elbow forward while its still pointing outward. The sharpest jolt happens after hours of having it in a neutral position, then after that theres only a slight tingling . Also whenever I rub that area at ANY given time or position, it is very numb. No trauma happened in area, and I ve done nothing really physical. Mostly do work on the computer and thats it. Can someone help?