Simultaneous bilateral hand strength testing in a client population, part I: diagnostic, observational and subjective complaint correlates to consistency of effort.
OBJECTIVE
1. To determine if scores on pain questionnaires and overt behaviors during a functional capacity evaluation (FCE) were related to variability between repeated measures during a hand strength assessment. 2. To determine if failure of statistically-based validity criteria, as proposed by Schapmire, St. James and Townsend et al. [26] is likely to be due to pain.


METHODS
200 consecutive clients presenting for an FCE.


METHODS
Subjects filled out pain questionnaires, were observed for various behaviors and were administered the distraction-based hand strength assessment.


RESULTS
Clients failing two or more of the statistically-based validity criteria had higher scores on most pain questionnaires, presented with a higher frequency of various pain behaviors (p < 0.05 and < 0.001, respectively), and had a lower rate of relevant surgeries (p < 0.001). There was no statistically significant difference in the number of failed validity criteria between this group of clients and for normal subjects feigning weakness in a controlled study (p> 0.05).


CONCLUSIONS
Pain does not reasonably explain the failure of the statistically-based validity criteria. The protocol is appropriate for use in a client population.
Schapmire
Darrell W
DW
X-RTS Software Products, Inc., Hopedale, IL 61747, USA. ds@xrts.com
St James
James D
JD
Feeler
Larry
L
Kleinkort
Joe
J
D001519:Behavior; D018737:Hand Strength; D006801:Humans; D010146:Pain / Q000150:complications / Q000523:psychology*; D010147:Pain Measurement / Q000379:methods / Q000523:psychology*; D005082:Physical Exertion; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014938:Work Capacity Evaluation