Pronator Teres Syndrome (Median Nerve)

Who: Manual trades and lifters. Repetitive gripping and pronation-supination load.
What: Proximal median nerve entrapment in the forearm.
How it behaves: Forearm pain and median-distribution paraesthesia. Worse with gripping and pronation. No nocturnal symptoms, or far less than carpal tunnel. Eased by rest.

The one thing to take from this page:

Electrodiagnosis may be negative in pronator syndrome. So a normal nerve conduction study does not clear it — and this diagnosis is made on anatomy, history and local provocation.

That is the central message of the current concepts literature [1], and it is what separates a student who reasons from one who waits for a test.

Same nerve, four places

And they can coexist. A released carpal tunnel that still hurts is a reason to look higher [2].

⚠️ No guideline exists. The literature here is reviews, small series and case reports — which is itself a statement about how often this gets recognised.

Five stages, in your course's order. The location of the dominant tenderness is the diagnosis — and the night question is what rules the alternative out.

MAIN PROBLEM

"My forearm aches and my thumb side of the hand tingles."
"It's worse when I'm gripping or turning a screwdriver."
"No, it doesn't wake me."

That third answer is doing real work.

BODY CHART

• Map the median territory in the hand — and mark where the dominant pain actually is. Proximal volar forearm is this pattern; wrist and hand alone is carpal tunnel.
• Mark the pronator teres region and, separately, the lacertus just medial to the biceps tendon.
• Draw the neck too. C6–T1 is on the list.

BEHAVIOUR

HISTORY

• Occupational and sport load — tools, torque, gripping volume, lifting, racquet or throwing exposure. This is the exposure and usually the treatment.
• Any previous carpal tunnel surgery, and whether it helped. Ask this explicitly.
• Previous investigations — and what the nerve study showed. A normal one does not close the question.

SPECIAL / SCREENING QUESTIONS

• Thumb, index or middle weakness; difficulty making an "OK" sign — the anterior interosseous screen.
• Thenar wasting, pinch weakness, dropping objects — motor involvement, which escalates the pathway.
• Neck symptoms — the radiculopathy and double-crush question.
• Diabetes or systemic neuropathy risk.

The two the table doesn't separate

Lacertus fibrosus compression — suspect it with pain on resisted elbow flexion and supination rather than resisted pronation. Superficialis-pronator compression sits more distally. Both are distinguishable from classic pronator teres syndrome, and the distinction matters because the surgical decision differs [3].

And the honest framing: proximal median compression is best thought of as a spectrum rather than pronator-versus-AIN, and localisation needs history, examination, electrodiagnosis and ultrasound together — it spans several zones from plexus to forearm ([4]; Rodner et al. 2013).