Caliper motion

Caliper motion (with flexion-extension of sacrum) (Fig. 57-8A). 

FIG. 57-S PubK motions. (A) Caliper motion BJ Torsional motion. (C) Superoinfetior translatory motion. 

FIG. 69-4 Rib motions (A) Bucket handle motion (B) Pump handle mot on. (C) Caliper motion. 

An orthopedic prosthesis is an internal or external device that replaces lost parts or functions of the neuroskeletomotor system. In contrast, an orthopedic orthosis is a device that augments a function of the skeletomotor system by controlling motion or altering the shape of body tissue. For example, an artificial leg or hand is a prosthesis, whereas a caliper (or brace) is an orthosis. This chapter addresses only orthoses and external orthopedic prostheses internal orthopedic prostheses, such as artificial joints, are a subject on their own. 

The eleventh and twelfth ribs have only costovertebral articulations. Because there are no transverse process limitations, the motion of these ribs is caliper-like along a horizontal plane. This motion produces slight changes in both the anteroposterior and the transverse dimensions. 

These ribs are evaluated with the patient prone. Their caliper-type motion is evaluated. 

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