How to perform leg extensions correctly and safely which will help prevent injury.
Muscles Involved in order of importance:
Then raise your legs upwards utill your knees aare locked out.
Lower your legs back to the starting position making sure your toes do not go behind your knees other wise that will put stress on the knee joint.
Safety: Doing this exercise should be done with a spotter if you think the weight will be a bit too much, I also have a spotter when doing this exercise just to be on the safe side.