What motions are involved in the E400 elbow for locking and unlocking?

The E400 elbow prosthesis incorporates motions that include depression, extension, and abduction for the purpose of locking and unlocking the unit. This design allows for enhanced functionality, facilitating a range of movements that are necessary for adapting to various tasks in daily life.

Depression, which refers to the downward movement of the joint, is essential for stabilizing the arm when the elbow is locked. Extension allows for the straightening of the elbow, which is crucial for many activities, while abduction helps in moving the elbow away from the body. This combination of motions effectively enables the prosthetic elbow to function in a manner similar to a biological elbow, thus allowing for a greater degree of control over both the locking and unlocking mechanisms.

The other motions mentioned in the answer choices do not accurately describe the actions required to lock and unlock the E400 elbow. Understanding these specific movements is key in ensuring users can operate the prosthetic efficiently and maximize their functional capabilities.