Fig. 71.—Flexures on palm of right hand. Drawing made from impression.
The most common types of them in the hand of man are shown in the example given in Fig. 71.
1. A flexure over each phalangeal joint.
2. A flexure at the bases of the digits.
3. A flexure over the metacarpo-phalangeal joints of D 2, 3, 4 and 5 with an oblique direction, called linea mensalis.
4. A flexure over these same joints and oblique in direction, but nearer to the wrist—the linea cephalica. These flexures 3 and 4, though arising from the flexion of one set of joints should be looked at as separate folds because of their time-honoured popular names.
5. A curving flexure surrounding the thenar eminence, extending from the centre of the wrist along the palm and terminating at the radial border.