Spasticity refers to muscle twitching or stiffness of the arms and legs due to diseases of the central nervous system. The main manifestation is the increase of muscle tone or muscle stiffness, resulting in a fixed movement of the limb, or even passive movement difficulties as a typical manifestation. It is commonly caused by central nervous system diseases and spinal cord diseases, such as spinal cord injury, which can show spasticity of the limbs below the control stage, leading to pain and skin breakdown, and some can cause sleep disorders and postural control. There are also beneficial aspects, such as helping the patient to use muscle tone to maintain posture or to perform activities of daily living such as standing and walking. There are also patients who can use spasticity to help protect the atrophied muscles, but long-term spasticity has a more significant impact on the patient and should be treated with medication or non-medication to reduce the patient’s spasticity symptoms.