A quick-release tube clamp and method therefor for locking and releasing a prosthetic pylon/foot component from the socket. The quick-release tube clamp includes a tubular portion, an annular socket portion, and a clamp portion. The tubular portion has a formed slot along a longitudinal length of the tubular portion. The tubular portion forms a cylindrical opening with an inner diameter slightly larger than the outer diameter of the tubular pylon. The annular socket at the upper end of the tubular portion attaches to the socket of the modular lower limb prosthetic system. The clamp portion is located near the lower end of the tubular portion and firmly locks the tubular portion around the tubular pylon when the tubular pylon is inserted into the tubular position and provides a releasing position for removal of the tubular pylon.