Hi Lucan,
You have already received some great advice.
The Sciatic nerve runs through or around the piriformus, mostly around. If you have damaged the muscles in this area leading to an inflammatory response, then it is possible that the nerve could be constricted, leading to pins and needles in your leg.
My advice to would be to see a health professional. In the mean while there are some stretches you can do to free the sciatic nerve. A simple one is to sit on a table so your knees border the edge. Slump your back with your chin into your chest, stretching the spinal cord. Then slowly lift your right leg till you fell the sciatic nerve stretching.