Lots of people don’t know how to contract the lower back muscles.
“A lifter who can’t control his lumbar spine isn’t as good a lifter as he can be.”
For some subtle cues like placing the thumb and fingers on the muscle bellies of the athlete’s erectors at the level of about T8, and then trace the muscles down to the sacrum is enough to get the desired result.
Not so subtle, but highly effective
“I want you to drop your dick down between your knees.”
Sometimes it even is enough to lay the palm of the athletes hand flat across your lower back and produce the contraction as an example of what I want him to do.
If that doesn’t bring the desired result, he uses the following drill.
I lay the guy down on the floor on his belly with his hands behind the head. I have him relax his chest into the floor and then I say, “Lift your chest and elbows up off the floor.” This produces an extension in the thoracic area of the back, well above where I want it. I have him do this a couple of times, and then explain that this is lifting the chest.
Next I say, “Lift your knees and feet clear of the floor. Keep your knees straight.” I have him hold this contraction for a few seconds, and then I touch the lumbar muscles, which are now in contraction.
“Do you feel the difference between this and raising your chest up?” He can now feel my hand on the muscles, like before when he was standing, unable to make them contract, but now they’re tight – he has produced a voluntary contraction in the muscles that before were unresponsive to the command.
I let him relax a second, and then he does a set of 10 reps, holding each arch for a couple of seconds. At the end of 10 reps the previously lazy muscle bellies have accumulated some lactate, and the burn is an identifiable product of the contraction.
Then I stand the guy up and tell him to make the same motion he did on the floor. The muscles are still burning, and he remembers exactly what action made this happen. A combination of these cues and this position on the floor works every time.