Affiliations: Oakland University, Rochester, MI, USA. University of
Indianapolis, Indianapolis, IN, USA
Note: [] Address for correspondence: Dr. Lynn R. Surrey, Oakland
University, School of Education and Human Services, Rochester, MI 48309, USA.
Tel.: +1 248 370 2524; Fax: +1 248 370 4141; E-mail: [email protected]
Abstract: Since a patient's ability to perform simulated work activities
guides return-to-work decisions, a significant question to address is whether
the simulated work environment accurately reflects the actual work environment.
Work hardening programs have been used extensively as a method of
rehabilitating workers to return to their pre-injury functioning levels.
Re-training workers to lift boxes is a common method used to simulate the work
environment. Although very few boxes used in the real work environment have
handles, boxes with handles are often used in the simulated work environment.
The difference in compression forces at the L5/S1 joint while lifting boxes
with and without handles was investigated. The Lift Trak Motion Analysis system
was used to estimate lumbar isometric compression forces exerted while lifting
a 20-pound (9.07-kg) box. The results indicated that estimates of compression
forces when lifting a box without handles were significantly different (p <
0.01) than when lifting the same box with handles. Based on these results, it
is recommended that work hardening professionals carefully re-evaluate the
simulated work environments currently being used for treatment.
Keywords: work hardening, simulated work environment, compression forces L5/S1
