From a medical point-of-view, these cyborg automails are not entirely impossible, and I hope they'll one day become a reality to aid amputees get a more practical life. The current hurdles are getting a reliable interface to the brain that doesn't take years to learn (like those neural game controllers; they're incredibly difficult to control) and decently strong electric or pneumatic muscles (servos, stepper motors and solenoids just don't work on human-scale strength). Though, their attachment to the chest is always so unnaturally depicted in art. For forwards and backwards motions of the arm, muscles of the chest (pectoralis) and back (trapezius) are all required. In this character, the chest muscles appear fully intact, while not attached to the cyborg-arms at all. A more realistic depiction would be if the artificial arm is attached to the scapula bone and to the sternum
What? I'm serious! I saw a documentary sort of thing about how the DX HR augmentations were a fairly realistic extension of what we have now, considering the time the game is set in.
The points you see running over his chest between the shoulders may have something to do with the forwards motion as its also likely that its a frame-like structure that's built under the skin.