Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

Muscle strength grade 2 allows for what type of range of motion?

1. Full ROM with decreased strength

2. Full ROM against gravity

3. Full ROM w/ gravity eliminated

4. Normal strength

The correct answer is: Full ROM w/ gravity eliminated

Muscle strength grade 2 corresponds to the ability of a muscle to perform a movement through its full range of motion, but only when gravity is eliminated. This means that the muscle can move a joint completely through its range without the opposing force of gravity impacting the movement. This grading is part of the Medical Research Council (MRC) scale for muscle strength assessment, where grade 2 indicates the muscle can contract and demonstrate some movement but lacks the strength to overcome gravity. Therefore, during this assessment, if a patient is able to move their limb freely through its full range when positioned in a way that gravity does not affect the movement (such as lying down), it reflects a grade of 2. The other options imply scenarios that do not fit the criteria for grade 2. For instance, the full range of motion against gravity indicates a higher strength grade, while full range of motion with decreased strength or normal strength does not accurately represent the capabilities outlined in the context of grade 2 muscle strength. Thus, the correct option accurately reflects the condition described in the question.