Single leg heel raise on step - slow eccentric phase (Gastrocnemius/medial arch strengthening, on step, single leg, behind chair)

Stand on a step with the ball of your foot.
The back two thirds of your foot should extend over the edge of the step.
Stabilize and control your body with your fingertips on a supporting surface or handrail.
Transfer your weight onto one leg then raise up onto your toes on that foot slowly, keeping the foot and medial arch stable.
Hold this position, supported on one foot and then lower your heel with a slow and controlled eccentric motion on one leg, maintaining the medial arch of your foot throughout the exercise.
Repeat this movement.