In medicine and anatomy, the outward rotation of the hand by rotating the forearm, so that the ulna and radius are parallel to each other after the rotation, is referred to as supination ( Latin supinitas , `` bent back position '' ) . When the arm is hanging, the palm is now facing forward.
Pronation is the opposite of supination. During this rotation of the forearm, the ulna and radius cross each other; when the arm is hanging, the palm now points backwards.
On the feet , supination describes the raising of the inner edge of the foot while simultaneously lowering the outer edge.
The supination (in this case the thumb points outwards and the palm points upwards) and pronation of the forearm take place through a flapping movement of the ulna and radius . The muscles responsible are the biceps brachii (biceps of the arm), the supinator muscle (outward rotation ) and the brachioradialis muscle . Participating joints are the proximal radioulnar articulation and the distal radioulnar articulation ( proximal and distal radial-ulnar joint).
Supination of the foot
On the feet , supination describes the lifting of the inner edge of the foot while simultaneously lowering the outer edge. Supination is sometimes referred to as an outward curl or outward twist. The opposite movement is called pronation. Further movements of the foot are adduction (moving the foot to the center) and abduction (moving the foot outwards), plantar flexion and dorsiflexion .
In addition, the following muscles also have a supinating effect:
- Tibialis posterior muscle (posterior tibial muscle )
- Flexor hallucis longus muscle (long big toe flexor )
- Flexor digitorum longus muscle (long toe flexor)
- Musculus tibialis anterior (anterior tibial muscle , at best has a weak supinating effect).
The muscles acting supinatorially outweigh their opponents ( antagonists ). This is one reason the foot takes a slightly supinated position during a jump. If the foot comes into contact with the ground again, it can come to the point that it touches down with the outer edge of the foot and kinks over the outer edge, which can lead to injuries to the outer ligaments.
Participating joints are the articulatio subtalaris and articulatio talocalcaneonavicularis (both together form the lower ankle ). The supination of the foot is superimposed by adduction and plantar flexion . This is related to the position of the axis of movement of the lower ankle joint. The superposition of the three movements supination, adduction and plantar flexion is also known as inversion .
- Franz-Viktor Salomon: musculoskeletal system. In: Franz-Viktor Salomon et al. (Hrsg.): Anatomie für die Tiermedizin . Enke-Verlag, Stuttgart 2004, ISBN 3-8304-1007-7 , pp. 22-234.
- W. Platzer: Pocket Atlas of Anatomy. Volume 1: musculoskeletal system . Thieme Verlag, Stuttgart 2005, ISBN 3-13-492009-3 , p. 124.