Stiff or Straight Leg Deadlift (S-DL) works the lower back, and the hamstrings, quite a lot. The exercise does this in two distinct ways, during both the “positive” and “negative” phases of the exercise.
“Straight” Leg means having the legs in a naturally straight position, a bit like when stretching while “touching your toes”.
“Stiff” Leg means having a slight bend in the legs to take tension off the hamstrings, but keeping this slight bend (i.e. keeping the legs “stiff” even if not fully “straight”) throughout the exercise.
The positive phase is when you lift upward from the bent over position and straighten the body. Here the muscles are contracting in order to lift both your body and any weight you have in the hands.
The negative phase is when you are lowering your body and the weight into the bent over position (ideally aiming to have the weight touch the floor, but if this is causes too great a stretch then the weight can be lowered onto a raised platform such as a box etc). During the lowering phase the muscles work to resist too great a pull downward (i.e. to stop you falling over etc).
During the negative phase the muscles are being stretched, but they can’t fully relax; they are being stretched while under load from the weight (hence this is not just a strength exercise it is also a loaded stretch).
Loaded stretching can be a very effective way of developing flexibility and mobility, but it can also be seriously hard work at times. Bear in mind that the more weight you use, not only the stronger you need to be during the positive, contracting, lifting phase, also the more demand one places on the muscles’ ability to stretch while under load during the negative, lowering phase. A great many serious strength athletes may well perform a good clean deadlift to “lock out” at the top of the exercise (thus being awarded a sport-legal lift) but then virtually drop the bar afterwards, or at least lower it again with no attempt at anything beyond the most basic control to stop it rolling away etc. Lowering the bar with full control after a deadlift can often be harder than doing the actual lift itself.Tweet this!