Human leg in a straight line, which represents the mechanical longitudinal axis of the leg, the Mikulicz line. This line stretches from the hip joint (or more precisely the head of the femur), through the knee joint (the intercondylar eminence of the tibia), and down to the center of the ankle (the ankle mortise, the fork-like grip between the medial and lateral malleoli). In the tibial shaft, the mechanical and anatomical axes coincide, but in the femoral shaft they diverge 6°, resulting in the "femorotibial angle" of 174° in a leg with normal axial alignment. A leg is considered straight when, with
Tibia Clausa alternate name for Doppelflöte. Most tibias are made from wood, as by Wurlitzer etc., although examples of metal tibias may be found made by the John Compton Organ Company. The Tibia Clausa, or Tibia, is generally found at 16′, 8′, 4′ and 2′ pitches as a unified rank. The mutation ranks Tibia Quint 5⅓′, Twelfth 2⅔′ and Tierce 1′ are also drawn from this unified rank of 97 pipes. In some larger organs, a second Tibia rank may be present, extended to 1′ instead of 16′, allowing a 1⅓′ Nineteenth mutation and a 1′ Piccolo to be drawn from this