The influence of age and exercise on the mobility of hand joints: 1: Metacarpophalangeal joints of the three-phalangeal fingers.

Mobility of metacarpophalangeal joints (MP) of the three-phalangeal fingers was measured in university students (52 males and 49 females), senior citizens (30 males and 30 females), and pianists (21 males and 31 females). We consider the student data file to be a control group with hand mobility unchanged by external influence. Extension, flexion, and total abduction in this group are greater in the left than the right hand. Only extensions were greater in females compared to males. In seniors, all types of studied movements are, with the exception of total abduction in females, lesser that in the control group. The difference is more apparent in males than in females. Intersexual difference showing better MP joint mobility in females than males is thus greater in seniors than in students; however, greater mobility of MP joints in left compared to right hand is less noticeable. Compared to students, pianists show greater finger abduction, and--less markedly--also passive and active extensions, while we did not notice difference in finger flexion. Intersexual difference in MP joint mobility in pianists were not recorded, and better mobility on the left hand compared to the right hand was evident only in dorso-palmar movements in males (the exception was total finger abduction, which is greater for the left hand in males as well as in females). In the three studied series we did not register differences in interfinger abduction between the left and right hand or between sexes. Active dorso-palmar MP joint range of motion is greatest in the little finger and smallest in the index finger, smallest in seniors and greatest in pianists. In all three groups, the range is greater in the left than the right hand and in females compared to males.