40 patients who underwent a total knee arthroplasty procedure were randomized to receive continuous passive motion (CPM) exercise, in addition to a standardized post-operative rehabilitation program, bilaterally to the injured and uninjured side (n=20) or to the injured side only (n=20). The primary outcome of interest was pain on a Visual Analog Scale (VAS). The secondary outcome of interest was range of motion and the 10m walk test result on day 14. The results found that patients who performed bilateral CPM showed significantly greater improvement after intervention than the unilateral group, who demonstrated an increase in pain after CPM exercise at days 4, 7 and 14. However, no differences in range of motion improvement or 10m test results were observed between the two groups.