Step-Up

Faites attention à

• avoid · Vertigo / balance disorder — This is a single-leg press up onto an elevated surface with the other foot deliberately off the ground, so a loss of balance means falling sideways off a box with all your weight on one leg — a bad outcome whatever your knees are doing. Do not do it standing free. Substitute Wall Sit, which loads the same quadriceps and glutes with both feet planted and your back supported, and hold a shorter time at a higher position rather than stepping up at all.
• caution · Uncontrolled hypertension — A hard single-leg effort with the breath held at the top produces a much bigger pressure spike than the movement looks like it warrants, and the natural instinct is to grunt or hold on the drive up. Keep the breath moving — out on the way up, in on the way down — stay well below failure, and use a lower box for more reps rather than a higher one for fewer. Avoid until your pressure is controlled and cleared. Stop on headache or spots in your vision.
• caution · Osteoporosis — Single-leg loading is a good stimulus for bone, and a fall off a box is not — so the risk here is the balance demand and the forward lean that some people use to stand up, which loads a thoracic spine with reduced density into flexion. Start with a low, stable surface, keep the chest tall, and stay within reach of a wall or a spotter. If you have had a vertebral fracture or lost height, get the safe step height and load from the clinician managing your bone density before working from an elevation.
• modify · Acute knee injury — The whole movement is a single knee taking your full bodyweight through a deep bend, and the trailing foot hovering means there is no second leg to help when the working knee complains — which is exactly when form goes and the knee caves inward. Lower the box until the front knee bends comfortably and stays over the ankle, keep the toes of the trailing foot down so you have a fallback, and stop the set when the knee starts to lead the push. If a deep bend is the limit, substitute Bodyweight Squat to a shallower depth, or Glute Bridge, which loads the hip with the knee in a safe fixed bend.
• modify · Acute lower back injury — The common cheat is to lean the torso forward and then stand up by hinging, which turns a leg exercise into a loaded single-leg hinge — fine as a technique, unwise for a reactive back. Keep the chest tall as step 3 says and rise by straightening the hip, not by folding and unfolding the spine. A shorter step up with more reps is a better deal than a high box you have to lurch onto. If the back takes over every set, substitute Wall Sit, which loads the legs with the spine supported by a wall.