A prosthetic attachment system and corresponding lock assembly for connecting a distal end of a prosthetic liner to a distal end of a prosthetic socket. The lock assembly includes a base arranged to be supported by the distal end of the prosthetic socket, and defining a bore. An attachment pin is arranged to be carried by the prosthetic liner and insertable through the bore. A lock mechanism is arranged to be carried by the base and is rotatable about a rotation axis. The lock mechanism includes a control knob extending outwardly from a side of the base. The attachment pin is arranged to interact with the lock mechanism cause the control knob to spin at least one projection of the control knob about the rotation axis.