Muscle stiffness may be associated with increased muscle tone and muscle ossification. If a patient develops symptoms of muscle stiffness, it is recommended that the patient go to the hospital as soon as possible. 1. Increased muscle tone: e.g. Parkinson’s disease. Parkinson’s disease patients with nigrostriatal dopaminergic neuron degeneration and death, the body of the extensor and flexor muscle tone increases, the patient will appear muscle ankylosis, muscle stiffness, random movement reduction, motor retardation and other symptoms. 2. Muscle ossification: patients need long-term braking during the recovery period of long bone fracture of the limbs, calcium may be deposited in the muscles, which may lead to muscle ossification, and patients may have symptoms such as muscle stiffness, local hardness, and activity limitation. It is recommended that the patient go to a specialized hospital for a clear diagnosis and early treatment to prevent delays.