The Load-Endurance Relationship for a Static Manual Response

Abstract

Each of 64 male subjects was required to maintain certain proportions of his maximum response strength as long as possible. An essentially linear relationship was obtained between the relative load (the percentage-of-maximum strength) and the endurance of the manual response within the range of loads employed. As the load was increased from 50% to 80% of maximum strength, the mean endurance of manual pull decreased from 63.3 sec to 21.4 sec. A comparison of endurance scores for two arm positions yielding different response strengths revealed little difference in performance despite the fact that the mean force to be maintained was 41% greater at one arm position than at the other. Thus, relative loading tended to equalize endurance despite large differences in the actual force of the sustained response.