Using the force-time curve to determine sincerity of effort in people with upper extremity injuries.
This was a prospective cohort study. In a previous study, the slopes of the force-time (F-T) curve were shown to differentiate between maximal and submaximal grip effort in healthy participants. The objective of the study was to examine if the slopes of the F-T curve can determine the sincerity of effort in people with upper extremity injuries. Forty participants with unilateral upper extremity injury performed maximal and submaximal grip efforts. The F-T curve was recorded, and the slopes of the force-generation and force-decay phases were calculated. Repeated-measures analysis of variance revealed significantly steeper slopes for maximal than those for submaximal efforts. However, receiver operating characteristic curves showed that, at best, the slope of the force-generation phase yielded overall error rates of 55% for women and 60% for men. Therefore, sensitivity and specificity values were insufficient to effectively differentiate maximal from submaximal efforts. The slopes of the F-T curve did not validly measure the sincerity of effort in participants with upper extremity injury, perhaps, because they were protective of their injured hand and, thus, exerted only submaximal effort even at their best grip attempt.


METHODS
Not applicable.
Department of Occupational Science and Technology, College of Health Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA. sindhu@uwm.edu
Bhagwant Singh
BS
Sindhu
Orit
O
Shechtman
D000293:Adolescent; D000328:Adult; D000368:Aged; D001134:Arm Injuries / Q000175:diagnosis* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D005260:Female; D018737:Hand Strength; D006801:Humans; D008297:Male; D008306:Malingering / Q000175:diagnosis; D008875:Middle Aged; D005082:Physical Exertion; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D055815:Young Adult