You can look up the codes from the photos here
For example:
C5 - Trunk-extension (standing)
The patient standing bent forward is to stretch the trunk backward.
The patient places himself upon the foot-board of the apparatus with his legs against the cushioned cross-bar, which is to be so adjusted that it touches the upper third of the thigh. After the leather-straps have been put on, the hands are pressed to the sides, and the thumbs should hold the straps so that they do not slide upward. That the straps may be easily put on and taken off, the lever of the apparatus is fastened in an horizontal position by a catch. During inspiration the upper part of the body is bent backward 45° without removing the thigh from the crossbar or bending the knees; during expiration the patient bends as far as possible forward.
Effect: on a number of muscles at the back of the body from the neck down to the calves.