Monday night's workout started off with some barbell RDLs. RDLs are a great hamstring and glute exercise and really help with your other deadlifts and leg exercises as well.
RDLs are often confused or misnamed with stiff legged deadlifts. The major difference between the two is that RDLs have the knees slightly bent where as the stiff legged deadlifts - yup you guessed it, have the legs extended fully. They wouldn't call it a stiff legged deadlift if your freakin knees were bent. They are two different exercises with different goals.
RDLs should have little to no back involved -more like none, if you do it right. It is a true posterior chain movement that hits the glutes and hamstrings hard.
You can go fairly heavy as long as your core can isolate and keep the legs doing the work. As soon as you lose that and feel your back involved then drop weight.
A stiff legged deadlift will invariably involve the lower back more as well as hamstrings and glutes. I was never fond of this version because of the inherent risk to the lower back. But done safely, it can be used to get the entire back side strong and conditioned.
Problem with it, is that too many people think that the lower back is a prime mover. It's not a prime mover in any exercise, ever but if you look around, there are dudes and women with strong backs, lifting tons of weight. Back lifters are their own breed and you can't tell them anything so let them rock on with their herculean lower backs.
For normal people who want healthy backs and strong legs - try doing it correctly by hinging at the hips, driving your butt back and leaning forward until the barbell drops just below your knee. Keep your shoulder blades pinched together and maintain a flat back. Then exhale and drive your glutes forward to peak contraction while you stand up tall, keeping the core braced. You should feel glutes and hamstrings doing all the work. NO Back !!!
Hope this helps. Train hard and stay safe.
Master Sergeant, U.S. Army Retired
NASM Certified Personal Trainer and Weight Loss Specialist
Graduate Student In Exercise Science At Cal U.
Dempseys Resolution Fitness