Development exercise for leg strength.
Put yourself in the Neutral Spine Position, stand with your feet shoulder- or hip-width apart. Throughout the move hold your arms and hands out in front of you for balance; keep your back straight; keep your head up, looking forward not down.
Slowly bend your knees and lower your bottom into a "sitting position", making sure you keep your weight over your heels, not your toes, then rise back up to a standing position.
Make sure your feet stay flat on the ground and that your knees ‘track’ your toes
Repeat the exercise.