2. Knee: Mini Step-Ups
A. Stand with feet hip-width apart, facing a staircase or a sturdy stepstool. Place your right foot on the first step.
B. (Shown) Raise yourself onto the step by straightening your right leg until it is almost fully extended, as your left foot lifts off the floor. Keep right knee slightly bent to protect the joint and challenge your front thigh muscles.
C. Return to starting position, but keep your right foot on the step. Do 10 reps; switch sides.