Can I ask what physical shape you are in?
Are you carrying more weight than usual?
Had any recent back or hamstring issues?
Neck problems?
Increased stress?
Regular exercise?
The reason i ask is that I have had a back/disk issue due to scar tissue from broken ribs near where the spine meets them, which has caused some numbness and tingling from time to time, but by getting remedial massage, losing 10 kg and strengthening my back and stomach muscles I have been free of the sensations for a while now..
Good luck..As someone at the start if his career i hope to get lucky and have 30 years + at like you..