Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

What muscle strength grade would indicate a full range of motion with decreased strength?

1. Muscle strength grade 3

2. Muscle strength grade 4

3. Muscle strength grade 5

4. Muscle strength grade 2

The correct answer is: Muscle strength grade 4

Muscle strength grade 4 indicates a full range of motion against gravity with some resistance, but the strength is diminished compared to the normal. This means the muscle can perform its full range of motion but with less than normal force. In practical terms, this often translates to the ability to overcome some resistance but not to the fullest extent expected of an intact muscle. It's important to understand the grading system for muscle strength. A grade of 5 signifies normal strength, where the muscle can withstand maximum resistance. A grade of 3 indicates full range of motion against gravity but no additional resistance, indicating adequate strength but not full capability. A grade of 2 suggests full range of motion only when the force of gravity is eliminated, highlighting even greater weakness. Thus, the description of having a full range of motion along with decreased strength aligns with muscle strength grade 4, which reflects the ability to move through the complete range while demonstrating reduced force generation.