The pronator teres

(M. pronator teres)


The M. pronator teres is a two-headed (caput humerale and caput ulnare) skeletal muscle of the forearm with transverse muscle fibres on the front of the forearm. It is one of the muscles limiting the elbow and is responsible for pronating (inside rotation) the forearm as well as bending the elbow joint. The pronator teres plays an important role for quicker motions against resistance. The very sensitive middle arm nerve (nervus medianus) can be found between the two heads of the M. pronator teres.
An over-exertion of the M. pronator teres due to sports or work can cause an irritation of the origin of the tendon. This is the reason for problems with the forearm, which are described as golf-arm.
The antagonist of the pronator teres are the M. supinator and the M. biceps brachii.



M. pronator teres



Caput humerale: bony hump of the upper arm (Epicondylus medialis humeri)

Caput ulnare: triangular tuberosity of the ulna (Processus coronoideus ulnae)

Base: Outside of the radius (Tuberositas pronatoria)

Inside rotation of the forearm (pronation)
Bending the elbow (flexion)






Exercise example



Inside rotation (pronation) with the Iron Gym Arms (forearm trainer)


Course of motion:

  • Stand hip-width apart with knees slightly bent
  • Grasp the red handles of the forearm trainer (wrists are straight)
  • Stretch your arms forwards with a slight bending
  • Do not completely stretch the arms
  • Start an inside rotation (approximately 45°)
  • Slowly do the exercise for an increased use of muscles



  • Exhale while doing the inside rotation
  • Inhale while returning


Advices of proof:

  • Motion comes from the forearm
  • Elbows are slightly bent
  • Do not over-stretch the forearm
  • Tense abdominal and back muscles
  • Avoid deviating motions


Create a varied and effective workout for the M. pronator teres by means of different training equipment. Use the following training equipment for strengthening the forearm referring to inside rotation.

Small equipment:

Bulky equipment:



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