A muscle strength rating of 4 on a scale of 0 to 5 means the muscle can move against gravity with some resistance. This indicates moderate strength, where the muscle can resist additional force beyond just lifting the limb but not full or maximal resistance. It is considered less than normal strength, which is the ability to move against gravity with full resistance (rated 5).

Muscle Strength Grading Scale Highlights

• 0: No muscle contraction
• 1: Muscle contraction without movement
• 2: Movement with gravity eliminated
• 3: Movement against gravity only
• 4: Movement against gravity with some resistance (moderate strength)
• 5: Movement against gravity with full resistance (normal strength)

Thus, a strength of 4 means the individual has fairly good muscle strength, though not full normal strength, capable of some resistance against applied force during muscle testing.