Put a negative bar behind the neck and shoulders, hold your chest high, tighten your waist, abdomen, slightly bend your hips, and stand comfortably and steadily at the shoulder-width distance. You can put a piece of wood or barbell on the heel to ensure the stability of your body when squatting and standing, overcome the forward bending and forward bending when standing, and keep the weight always acting vertically on the target muscle group of your legs. Keep the trunk vertical and slightly tight, control it with the strength of quadriceps femoris, keep balance, and slowly bend your knees and squat down until your thighs are parallel to the ground or at right angles or slightly lower, and your thoughts are concentrated. Concentrate on the quadriceps to stand until the legs are straight and the knees are straight, and the quadriceps completely contract to the "peak" state, pause 1 s, and then squat down smoothly for the next movement. When the load intensity is below 6-8rm, the breathing method is to exhale when standing up and inhale when squatting down, or stand up and inhale and exhale when squatting down, depending on the habit, but breathing must be coordinated with the action.
No disorder!
When lifting weights
Gravity passes through the human body to the heel.
The human body tends to lean back, so the heel is raised.
It can prevent you from falling backwards, and also help you concentrate and exercise your legs.
If you use Smith depth machine, you don't have to pay attention to this problem. It can help you keep your balance and prevent waist injury.
Safer than a free barbell squat.
I recommend you to use this