Nerve glide
Raise your arms out to the sides at shoulder height, with your elbows bent to 90 degrees and your palms facing forwards. As you tilt your head to the right, straighten your right elbow and lower your forearm out to the side, so that your right arm is completely straight. Come back to the middle. Then tilt your head to the left and do the same with your left arm. The nerve is tightened at one end while it is slackened at the other, so it glides without being stretched.
10 slow reps to each side. Stop if the numbness increases