Therapists' ability to identify safe maximum lifting in low back pain patients during functional capacity evaluation.

Functional capacity evaluation (FCE) of an injured worker's ability to lift weight guides the determination of whether he or she is capable of handling the physical demands of a job. The purpose of this study was to examine the interrater and intrarater reliability in determining the safe maximum floor-to-waist lift for patients with low back pain during FCE testing. Twenty-one patients with low back pain were evaluated. Patients were videotaped lifting weight in progressive increments using a kinesiophysical approach. Five experienced physical therapists viewed the videotape and judged the lifts for body mechanics safety. Safety reliability was high, indicating that therapists can accurately judge safe lifting methods during FCE. As lifting loads increased, body mechanics deteriorated, indicating the patient was approaching or had reached a biomechanical end point. Clinical information is needed, in addition to visual observations, to accurately determine when maximum lift capacity is reached.