Relationships among lifting ability, grip force, and return to work

The relationship between functional capacity evaluation (FCE) data and work disability has not been studied. The validity of FCE testing results in terms of subsequent return to work (RTW) was the focus of this exploratory study.

Six hundred fifty adults of working age were evaluated as part of a standardized FCE. Clients were contacted by telephone 6 months after the FCE to determine their work status. Predictor variables were gender, age, time off work, maximum safe loads during 3 dynamic lifts, and isometric grip force. Other variables measured were whether or not the client returned to work (RTW-Y/N) and level of return to work (RTW level).

A multivariate logistic regression analysis demonstrated that the more time a worker was away from work, the less likely was RTW. Male subjects were less likely to return to work than female subjects. The more weight lifted from floor to waist, the more likely was RTW. The logistic regression equation correctly classified 80.3% of the subjects who returned to work and 56.6% of the subjects who did not return to work. Each of the 3 lift tests was related to RTW level, whereas the grip force tests were not related to either RTW-Y/N or RTW level.

Time off work and gender were the strongest predictors of RTW, but certain FCE subtests of lifting were related to RTW and RTW level for people with work-related chronic symptoms. Grip force was not related to RTW.