Two degree of freedom,myoelectric control,prostheses for upper arm

1)Myoelectricity can control actions of hand and elbow.
2)Wrist can passively rotate and self-lock at an optional position.
3)If the myoelectricity can't be changed over,the passire switch changover can be added.
4)If necessary,a built-in battery can be used.
Suitable for middle,short stumps of forearm.