Muscle strength: the maximum contraction force during muscle movement. Examination method: The patient is asked to make a limb stretching movement, and the examiner gives resistance from the opposite direction to test the patient’s overcoming power to the resistance, and pay attention to the comparison between the two sides. Grading: According to the condition of muscle strength, muscle strength is generally divided into the following 0 – 5 levels, a total of six levels: Level 0 Complete paralysis, no muscle contraction can be measured. Grade 1 Only muscle contraction is measured, but no movement can be produced. Grade 2 The limb can move parallel to the bed, but cannot resist its own gravity, i.e. it cannot be lifted off the bed. Grade 3 The limb can overcome the geocentric absorption force and can lift off the bed, but cannot resist the assistance. Grade 4 The limb can make movements against external resistance, but not completely. Grade 5 Normal muscle strength.