Isometric torque of the finger extensors at the metacarpophalangeal joints

A pilot study was undertaken to evaluate the isometric torque produced at the metacarpophalangeal joint during finger extension. Fifteen women with normal right hands, aged 21 to 29 years, participated. Each subject was tested for maximal force of isometric extension at the metacarpophalangeal joint angles of 0, 30, and 60 degrees on each of the four fingers. Torque was computed by multiplying the recorded tension and measured length of the proximal phalanx (lever arm). The mean torque for the long finger was significantly greater than the average torque for each of the other three fingers. The mean torque at the joint angle of 60 degrees was significantly greater than at 0 degrees but not at 30 degrees. Reasons for the findings are discussed.