The muscle throbbing in the legs may be caused by the following reasons: First, it may be caused by over fatigue, for example, if the patient walks long distances or does excessive exercise for the lower limbs, it may cause excessive fatigue of the lower limb muscles, and the patient may experience muscle throbbing in the lower limbs during rest, and in serious cases, even cramps. Second, it may be caused by cold, if the lower limbs are exposed and cold for a long time, it may cause involuntary muscle contractions or cramps. Thirdly, it may be caused by high excitement and tension of the patient, if the patient has the above emotions, it may also lead to this abnormal activity of the muscles of the lower limbs. Fourth, it may be caused by some neurological related lesions, for example, in patients with lumbar disc herniation, due to the stimulation of the related nerve roots, resulting in excessive electrical stimulation of the muscles, which may also lead to muscle throbbing. In addition to this, if the patient suffers from a disease like epilepsy, due to the abnormal discharge of the brain, it may also lead to excessive muscle twitching in this area, which then leads to a throbbing.