Final answer:
To open the carpal interspaces on the lateral side of the wrist, tilting the hand to the side away from the body (radial deviation) is the correct maneuver. This aligns with the functions of the superficial posterior compartment of the forearm, which straightens the wrist and aids in this radial deviation.
Step-by-step explanation:
The wrist-positioning maneuver that opens the carpal interspaces on the lateral side of the wrist involves tilting the hand away from the body. This maneuver aligns with the actions of the superficial posterior compartment of the forearm, which is responsible for straightening the wrist and tilting the hand to the side away from the body. In practice, this would translate to a radial deviation, where the hand is moved towards the thumb side, opening up the space between the carpal bones on the lateral side. The mnemonic 'So Long To Pinky, Here Comes The Thumb' can be used to recall the arrangement of the carpal bones and reflects that this movement starts and finishes on the lateral side of the wrist.