Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Position a stability ball between your lower back and a wall. Stand with feet shoulder-width apart, leaning slightly against the ball. Engage your core, chest up. Slowly squat, keeping knees aligned with toes. Descend until thighs are parallel to the ground (or comfortable). Pause briefly. Push through heels to return to start, controlled movement. Repeat.
Ensure proper ball inflation. Distribute weight evenly through heels. Avoid knees extending past toes. Maintain a neutral spine. Engage your core. Perform slowly.
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