1
Sit upright on a chair with your back against the backrest, feet flat on the floor, knees bent at approximately 90 degrees. Keep your core engaged and hands resting on your thighs or at your sides for stability.
2
Position yourself so that one leg remains planted on the floor for stability while the opposite leg is prepared for the extension movement. Maintain neutral spine alignment throughout.
3
Slowly lower the extended leg by bending at the knee, bringing your foot back toward the floor in a controlled manner. The quadriceps lengthens as the knee flexes. This eccentric phase should take 2-3 seconds.
4
Drive through the quadriceps to extend the knee, straightening the leg fully or near-fully in front of you. Squeeze the quadriceps at full extension, then control the descent. Repeat for the desired number of repetitions before switching legs.