If the claimant’s range of motion is limited by a nonoccupational condition such as obesity the doctor should offer an opinion as to the functional loss and resulting SLU that is causally related to the work injury and not other factors. Where a claimant has preexisting osteoarthritis, which is exacerbated by a work injury, the measurement of the contralateral extremity should be used as a baseline whenever possible. Reductions in range of motion for the non-injured contralateral extremity are deducted from the loss of range of motion for the injured extremity.