Pronator Teres Syndrome:

From: www.wheelessonline.com

- Differential Dx:
     - lacertus fibrosus:
          - draws tightly across the median nerve when the forearm is held in resisted supination and flexion;
          - independent flexion of the middle finger flexion (FDS) localizes the level of entrapment to the fibrous arcade of the FDS;
     - flexor superficialis crossover syndrome:
          - resisted flexion of flexor superficialis of long finger combined w/ parasthesias in forearm & hand while pronating wrist, clinical test for
                median nerve entrapment at pronator teres & flexor superficialis cross over;
     - C6 / C7 radiculopathy:
          - involvment of these levels will cause numbeness of thumb, index, and long fingers, and the median nerve innervated muscles of the forearm;
          - the correct diagnosis is made by establishing the function of the muscles innervated by the C6-C7 portions of the radial nerve (ie the
                function of the wrist entensors and the triceps);

- Exam:
     - see: exam for carpal tunnel;
     - Phalen and tunnel test are negative;
     - pain in wrist and forearm;
     - weakness of thenar muscles;
     - thenar muscles are weak but muscles of ain (fpl, fdp, quad) are spared;
     - dysesthesia in "palmar triangle;"
          - pronator teres can be implicated when arm is held in resisted pronation and flexion and then gradually extended while in pronated position;

- EMG:
     - when EMG does not confirm pronator teres syndrome but clinical evidence is suggestive, then wait 4-6 wks and repeat the EMG;

- Treatment:
     - realease of humeral head of pronator teres and the superficialis bridge as well as associated compressing structures;