Dear Doctor
I experience a sudden loss of " strenght"  in my left leg while jogging on the road and/or the treadmill in the Gym. It feels like the two muscles, which work like two hinges in the crook of my left leg, is twitching suddenly from time to time. The twitch is just like it is suddenly give way and then its fine again for the next few minutes. It is like giving a warning and then I can continue running again until the next twitch in a few minutes time. I don' t experience any pain while walking neither when cycling! I do however struggle with a very stiff left leg calf which in the past tend to cramp! Any suggestions? Thanks