With the heel RuneScape gold not touching a surface, the weight is on the toes. Here the glutes can't help as much and it truly becomes a quad dominant movement. The further forward the knees, the harder it becomes for the quads. Some padding for where the free leg's knee touches the ground can help to avoid a painful impact.
you can use books or something similar under the free knee to do partial range of motion or under the working foot to do extra range of motion. Increase the intensity through more forward knee travel of the working leg by staying more upright or having one or both arms behind the body.
Strength potential: exceptional to elite for the quads, maybe world class with a full depth single leg version. Joint stress high, extreme if single leg. Skill: high, very high if single leg.Recommended prerequisites none, you can start with very low range of motion.
Find a foot width that works well for you to reduce stress gold grateful A simple way to progress this is starting in the kneeling position with the feet touching a wall behind you, going down until the head touches the wall and back up. Gradually increase the distance from the wall.