At the L5 level, which muscle is described as 2/5 strength?

• A. Hip abductors
• B. Lateral knee flexors
• C. Ankle invertors
• D. Long toe extensors

Answer: (B)

Movement graded as 2/5 means the muscle can move only when gravity is eliminated, not against gravity. At the L5 level, the lateral knee flexors (the hamstring group that bends the knee and rotates the leg outward) are the muscle set most typically described as weak to this degree. When L5 is the lowest functioning level, knee flexion can be accomplished only with the leg supported and gravity off the way, which matches a 2/5 strength pattern. The other muscle groups listed are more strongly tied to other myotomes or require involvement from higher or adjacent levels, so they wouldn’t uniquely manifest a pure L5 2/5 finding.