[Characteristics of the articulation heads in the elbow joint in relation to flexor-extension movements]

Abstract

The angles involved in the physiological movements of the humero-ulnar joint have been studied by a semiautomatic image analyzer on 50 dried humeri and 50 dried ulnae and on 50 radiographs of normal elbow joints (22 male and 28 female). The angle (A) formed by the diaphyseal axis and the lower humeral epiphysis equals 34 degrees +/- 3.97 (media + s.d.) in dried bones; 35 degrees +/- 6.05 (male) and 35.5 degrees +/- 4.7 (female) in the radiographic images. The angle (B) formed by the trochlear notch axis and the horizontal plane equals 22.5 degrees +/- 5.31 in the dried bones; 28 degrees +/- 5.57 (male) and 25.5 degrees +/- 6.98 (female) in the radiographic images. According to these data the flexor-extension movement of the elbow joint is possible when the humeral angle (A) is less than 45 degrees even if this angle (A) is required to be more than the ulnar one (B).