If you are unable to keep your back arched and chest up when bending over you should not reach for the floor. For some people (especially beginners) getting the leg bent into a 90 degree angle is enough.
Main Muscles: gluteus maximus, hamstrings, quadriceps
– Keep your chest high, back straight & core tight
– Give yourself plenty of space between the bench and your lead leg
– Keep your foot flat and push through the heel of the lead leg
– Squat until the knee on your lead leg is less than 90°
– Keep your chest behind your knees at all times