Objective: To determine whether the repositioning error of trunk flexion-extension in individuals with low back pain is different from that in those not experiencing low back pain when lifting and lowering external loads.
Design: A case-control study.
Setting: Physical therapy department of a medical centre.
Subjects: Twenty subjects with subacute low back pain and 20 control subjects without low back pain.
Interventions: Tasks with and without lifting and lowering an external load.
Main outcome measures: The trunk repositioning errors were measured with Measurand Shape Tape.
Results: In subjects with low back pain, trunk repositioning errors were significantly reduced when lifting and lowering an external load in the direction of flexion (3.779 ±1.26 degrees in a loaded condition versus 4.82±2.97 degrees in an unloaded condition; P B< 0.05) and extension (3.17±2.15 degrees in a loaded condition versus 5.039±3.74 degrees in an unloaded condition; p < 0.05). In control subjects, trunk repositioning errors were not significantly changed when lifting and lowering an external load in the direction of flexion (2.80±1.39 degrees in a loaded condition versus 2.63±1.24 degrees in an unloaded condition; p < 0.05) and extension (2.87±1.40 degrees in a loaded condition versus 3.15±1.50 degrees in an unloaded condition; P>0.05). The direction of motion (trunk flexion or extension) was not shown to be significant in this study.
Conclusion: Performing the task whilst lifting or lowering a submaximal load showed a reduced trunk repositioning error in subjects with subacute low back pain. Lifting and lowering a submaximal load might be considered as one of the rehabilitative strategies to hasten a return to work.