Elbow

Movements of radius and ulna

· pronation and supination produced by movements of radius and hand around immobile ulna

Axis of pronation-supination

· passes through centre of curvature of each radioulnar joint

· from centre of head of radius to base of ulnar styloid

· is oblique to shaft of ulna

· is in line with shaft of humerus

Axis of forearm

· passes

· from midpoint between epicondyles of humerus

· to midpoint between styoid processes of radius and ulna

· changes with position of rotation

· in supination is parallel with ulna

· oblique to shaft of humerus (carrying angle)

· in pronation is in parallel to axis of pronation-supination

· in line with humerus

Carrying angle

· angle between axis of humerus and forearm

· present in supination and disappears in pronation

· exists so that forearm is in line with forearm in working position (near full pronation)

Movement of ulna

· rotation accompanied by movement of ulna

· abduction and adduction

· occurs in two ways

· between ulna and trochlea

· with humeral rotation

· ulnar movement least when axis is medial (ie. around little finger)

· movement occurs at trochlea

· ulnar movemnt greatest when axis is lateral (ie. around thumb)

· movement also required by humerus

Movement of elbow

· ulnar abduction and adduction accompanied by elbow flexion and extension

· during pronation

· first half has abduction and extension of elbow

· second half has further aduction and flexion of elbow

· during supination

· first half has adduction and extension of elbow

· second half has further adduction and flexion of elbow