When attempting to get a client's arms out behind their back we need to follow 2 principles. 1) Use a simple machine (A Wedge) to have a mechanical advantage to open the elbow away from the body and 2) Cause an asymmetrical power difference by using our whole body vs our client's one arm. These 2 principles will give us a great advantage and a chance of dealing with a much larger and stronger client. Please note this is never a guarantee for success, just necessary steps in the right direction.

Wedge

A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place.

With this technique we use our knee as a wedge to move our client's arm away from their ribs/lat muscles. By using a large portion of our body mass with the assistance of gravity we can effectively and efficiently drive force downwards in a slow controlled manner to open the up elbow position. For extra power we can also use the strength of our legs to drive force forward. These kind of details are important to understand as it will allow you to improvise solutions to the various problems you may face outside the realm of the instrucional.