Relationship of triceps surae torques to photographed tibia-calcaneum angles in man (II).

A previous paper described an apparatus and method for giving the relationship between triceps surae torque and the tibia-calcaneum angle. As a first approximation we took the angle between the calcaneum and the foot-plate as being invariable in all subjects, when the torque was zero. The aim of the present work is to measure the inter-individual variations of the angle. 1. Guide-marks are selected on the skin; showing the axes of the calcaneum and of the leg. Metal rods indicate the axes thus defined and the true angle between the leg and the calcaneum is measured by photography. The curves drawn from these true angles differ from the preceding curves by 0 degrees to 10 degrees for normal children and +12 degrees to -15 degrees for cerebral palsied children. 2. The photographic method verifies the exactitude of the trigonometrical method of correcting angles that we proposed in the previous paper.