I recently took a part time one time job for a week where I sat a lot and the job was out of town and so I was driving in the car a lot. Ever since I was driving back home, I was feeling twitching and tightness in my arms. I thought it was a lack of mobility. It s been a few days since I have been back to normal but when I woke up this morning, I felt a bruise on my right arm but could see no bruise. It was around my elbow area. It has since moved to my forearm. My arms still feel tight but especially my right arm. I am a 31 year old female.