Development and construct validation of the Hand Function Sort

The construct validity of the Hand Function Sort (HFS) was investigated in 126 adults of working age (65% male) with medical impairments. Principal components factor analysis identified one major factor and two minor factors, which was consistent with the findings of a subsequent Harris Image Analysis. A Kaiser Image Analysis identified seven factors, partitioning the first global factor. Construct validity also was studied. HFS scores of subjects who had impairment of the dominant upper extremity were compared with subjects whose dominant upper extremities were not impaired. Significant differences were found between groups for total scores and in categories of tasks for which hand dominance was likely to be important. Conversely, there were no significant differences with tasks for which hand dominance was not important. HFS scores were compared with grip strength, which accounted for significant variance in the total HFS score. When categories of tasks were considered, substantial variance in the factors for which grip strength was important was accounted for by grip strength. For tasks in which grip strength was not likely to be important, variance accounted for by grip strength was negligible.