On the middle phalanx.
In general, stabilization of adjacent digits to give fixation of the digit toward the finger that is moved and to prevent assistance from the digit on the other side.
First: (Figure A) Adduction of the thumb toward the in- dex finger (acting with the adductor pollicis and first dorsal interosseous). Hold the thumb, and pull in the radial direction.
Second: (Figure B) Adduction of the index finger toward the middle finger. Hold the index finger, and pull in the direction of the thumb.
Third: (Figure C) Adduction of the ring finger toward the middle finger. Hold the ring finger, and pull in the direction of the little finger.
Fourth: (Figure D) Adduction of the little finger toward the ring finger. Hold the little finger, and pull in the ulnar direction.