Transhumeral Overview: Prosthetic Design, Suspension, and Components

Question 1

The trim lines for the elbow disarticulation must allow free motion of the glenohumeral joint. The socket extends as proximally as possible to provide stabilization, with the brim extending as far proximal as the acromion process.

Answer 1

False

Question 2

The control of socket rotation is a significant consideration in transhumeral prosthetic design. The proximal brim for each of the transhumeral designs presented here will have

Answer 2

A “D”- shaped cross-section at the axilla level in the socket

Question 3

For a long transhumeral amputation which is not bulbous distally, rotation cannot be controlled by the socket walls; the brim must extend to cover more of the shoulder. The socket trim lines are:

Answer 3

• the lateral trim line extends to the acromion
• the anterior trim line extends to the delta pectoral groove
• the posterior trim line should extend to the lateral border of the scapula

Question 4

The short transhumeral amputation must be stabilized to prevent rotation. In addition, the short humerus offers little in the way of stabilization of the prosthetic socket itself. Suspension is provided:

Answer 4

In part by the socket brim but mostly by the anterior and lateral suspensor straps

Question 5

Forearm lengths for the E400 and E200 elbows vary in 1/4” increments and are available from 7” to 11.5” in length. It isn’t necessary to specify right or left because the side is interchangeable.

Answer 5

False