Patch massager such devices are certain side effects, specifically the following: 1, may lead to sustained muscle spasms, this situation is seen in patients who choose substandard products, or a transient use of excessive stimulation. This may cause a certain muscle to remain tense for a long time and thus produce spasms. Some patients use too much stimulation intensity, may be in the use of such a massager, and continue to keep a part of the muscle throbbing, and a long period of time can not be relieved. 2, this massager in use, may cause patients in a period of time have muscle weakness. This kind of massage instrument is mainly through electromagnetic pulse, so that the local muscles to achieve contraction, relaxation, and then achieve the purpose of relieving fatigue, but if long-term excessive use may lead to muscle weakness. 3, may aggravate some conditions, such as in some parts of the patient muscle strain, if you take this kind of massage instrument, may lead to increased local muscle damage.