Quadriceps strength of grade 3 or less is associated with what outcome?

• A. Wheelchair users
• B. Running ability
• C. Wheel access only
• D. Improved gait speed

Answer: (A)

Quadriceps strength at or below grade 3 means the muscle can move the knee only against gravity and cannot generate knee extension against resistance. For walking, knee extension during stance is essential to support body weight and control the leg. When quadriceps are this weak, standing and stepping become unstable and energetically inefficient, making independent ambulation unlikely. In practice, this level of strength is most strongly associated with relying on a wheelchair for mobility. Running would require much stronger knee extension and control, and while gait speed might be affected, it wouldn’t be the typical outcome with this degree of weakness. Wheel access or other options don’t capture the functional limitation as accurately as wheelchair use does.