Postoperative muscle strength.

This study investigates the role of motivation in voluntary strength measurements during the postoperative period. Thirty patients underwent surgery which was deemed minor, intermediate or major in severity. Before operation and on the 4th postoperative day measurement of grip strength, maximal voluntary and maximal tetanic (stimulated) contraction of adductor pollicis and assessment of mood were recorded. These investigations were also repeated on the 7th postoperative day in those who had major surgery. No patient had postoperative complications. Minor surgery had no influence on any of the values. Those who underwent major surgery showed significant reductions in grip strength, maximal voluntary contraction and mood; however, maximal tetanic contraction was unaffected. The results in the intermediate group were similar to the major group, although mood depression was less marked. Real strength of a hand muscle appears to be unaltered even by major surgery, but voluntary muscle force is decreased by intermediate and major surgery, and correlates with the patient's subjective state of well-being.