consult your doctor prior to use of such products if you -lrb- 1 -rrb- have a medical or heart condition , -lrb- 2 -rrb- are taking any photosensitive medicine , -lrb- 3 -rrb- have epilepsy or are sensitive to flashing lights , -lrb- 4 -rrb- have reduced circulation or bruise easily , or -lrb- 5 -rrb- have tendonitis , carpal tunnel syndrome , or other musculoskeletal disorders .