A physical therapist is evaluating a patient that complains…

A physical therapist is evaluating a patient that complains of weakness in the hand.  The therapist decides to test finger flexion strength to differentiate whether the median or ulnar nerve is involved.  The physical therapist notes the index finger and middle finger (2nd and 3rd digits) are weak, while the ring finger and pinky finger (4th and 5th digits) are strong.  Given this information, which nerve is most likely involved in this condition?