Just measured the distance from the lower tendon of the biceps of my right arm to the notch between my thumb and the palm of my hand and it turned out to be 300 mm. Could the remen have been the distance from the upper arm to where one grasps something? One could probably check out that measurement on the statues of the period and compare them with values for the remen. The remen glyph shows part of the upper arm and the notch between the thumb and hand. Calling this distance a foot is a misnomer.