What indicates normal muscle strength on a grading scale?

Normal muscle strength on a grading scale is represented by a score of Grade 5. This grading scale evaluates muscle strength based on a maximum level of contraction against gravity and resistance.

A Grade 5 indicates that the muscle can maintain full resistance against an external force, meaning that the muscle strength is considered normal. In practical terms, a patient with Grade 5 strength can perform movements without any noticeable weakness and meets the expectations for healthy muscle function.

Grades lower than 5 reflect varying degrees of weakness. Grade 4 suggests that the muscle can move against some resistance, but there may still be slight weakness present. Grade 3 indicates that the muscle can move against gravity but cannot handle any additional resistance, suggesting reduced strength. Grade 2 signifies that the muscle has the ability to contract but cannot move against gravity, which further indicates a significant reduction in muscle power.

Thus, Grade 5 is the standard reference for normal muscle strength in the clinical evaluation of patients.