https://www.youtube.com/watch?v=Q2m3qCbinzA

After 30 years of practice there are some injuries that you know like the back of your hand. One such common injury is the lumbosacral hyperextension strain from leg lifts. It mostly happens to patients who have not been doing any form of core workout for while and decide to take on this rather challenging workout practice without the appropriate gradual ramp-up, but I've seen it happen even in seasoned gym rats. The problem is the amount of hyperextension loading when someone tries to do bilateral leg lift starting in a supine position with flat legs on the table. It's an extremely high leverage for the lumbosacral spine if the abdominals are not optimally efficient at immediate initiation and stabilization of the low back. Leg lifts can be a great addition to a core workout and can be safely done with 2 small modifications: starting with the legs in the up position, only lowering them in a range that allows the lowback to stay in contact with the exercise mat; during the exercise one leg at a time to build up strength and endurance and stability rather than both legs at the time, which may be achieved over time.