Physical Medicine and Rehabilitation (86)
Authors: Kilmer David D. , Aitkens Susan G. , Wright Nancy C. , McCrory: Megan A. 
Published: September 2010

Simulated work performance tasks in persons with neuropathic and myopathic weakness. (University of California, Sacramento, CA) Arch Phys Med Rehabil 2000;81:938–943.

This study aimed to determine the test‐retest reliability of selected simulated work performance tasks in persons with neuropathic and myopathic weakness and control subjects, and the association between muscular performance during these work tasks and conventional isolated muscle group testing. Measurement of 3 tasks was performed on a work simulation device on 2 different days separated by 1 week. Associations between work task performance and previously reported strength measures in 6 muscle groups by hand‐held dynamometry (HHD) were examined. This study was conducted in the human performance laboratory of a university and consisted of a convenience sample of ambulatory outpatients with hereditary motor and sensory neuropathy, type I (n = 9), myotonic muscular dystrophy (n = 10), and able‐bodied controls (n = 11). Mean between‐session differences for work simulation tasks ranged from −11% to +4% for peak torque and from −12% to +12% for total work; test sessions did not differ significantly for either patient or control groups. All groups had between‐session intraclass correlation coefficients usually> 0.80, which indicated good consistency. In general, correlations between peak torque during work simulation and HHD were strongest in the control group. Conclude that persons with neuromuscular weakness reliably performed the simulated work tasks examined in this investigation. Work simulation tasks may be a useful tool to assess muscular performance in persons with neuromuscular weakness.

Comment by Miles Day, MD.

This article addresses something that is very important when evaluating patient progress during rehabilitation. It is common in rehab to evaluate muscle groups and to determine a muscular performance by using isolated muscle group testing. The problem with this is that it doesn't necessarily correlate with tasks that patients perform on a day‐to‐day basis. The purpose of the study was to determine the test‐retest reliability of selected simulated work performance tasks in patients with neuropathic and myopathic weakness and control subjects and the association between muscular performance during these work tasks and conventional isolated muscle group testing. The work simulation tasks included knob‐turning (alternating pronation and supination), linear motion (alternating push/pull motion), and lever arm (push‐down motion). This study did accomplish its goals. The peak torque and total work measured in work simulation tasks did not differ significantly between test and retest sessions for either the patients with neuropathic and myopathic weakness or the control groups.

This study addresses an issue that other studies have not. Just because a patient shows improvement in strength measure by hand held dynamometry does not necessarily mean that he or she will be able to accomplish tasks that are performed at home. The main goal of rehabilitation is for patients to be able to perform activities of daily living around the house and at work. If this is not accomplished then their rehabilitation is for naught.