Yes, there are some medical reasons someone may have that they should not use a leg massager. A few of these are: If using a pacemaker or other medical device that may experience electrical interference. Having osteoporosis, malignant tumors, or cardiac disease. Trauma to the body that the leg massager be unsuitable for. Pregnancy If you are unsure if you have any condition that would contraindicate a leg massager consult a doctor before use.