^^^ This.
There are 2 exercises which I started doing to improve my Deadlifts (because you guys know how little I care about Squats). These exercises are probably THE most under-rated exercises but probably the BEST at improving your movement and making you injury proof. They are:
1.) Overhead Squats
2.) Pistol Squats
For OH squats you will need to start off with a broomstick. You will need to work on your hip mobility first then graduate onto overhead squats. Pistol Squats require dedication and most people don't want to do these so I won't push you with these. But OH Squats are probably one of the best core/hip exercises.
I feel like helping you but then again I don't feel like helping you. You haven't requested my help. You're still thinking in just one unilateral direction. Why do you need to restrict yourself to only machines or what not?
Firstly, you need to describe your injury. For example, two years ago (in my Sophomore year) I hurt my back due to incorrect progression. In 6 weeks I went from Deadlifting 135 lbs to 265 lbs. What did the injury comprise of? Well, the left part of my lower back - left to the spine, hurt a lot. It was a dull ache and because of that ache I couldn't do anything. It hurt when I bent down to brush my teeth, it hurt to sit, it hurt to move. Having sex was also a pain.
So what did I do? I didn't listen to the guys at GUStrength, I decided to be stubborn and I kept doing my own thing.
What happened?
The injury only got worse. It got so bad that I had to take pain killers every single day and I ended up not training for 5 months straight. You know how terrible that is? It was mentally unbearable.
So what did I do?
I took my head out of my ass and I requested Eric to take me under his wing and the first thing I did was listen to everything he said without questioning him. By this time it had been established that I really did NOT know what the fuck I was doing and spinning my wheels and getting injured was not a good idea.
So, I was blessed enough to be accepted by him and he literally nursed me back to health.
I believe I have a log of this which you can read up on (and I suggest you do because at the time I was interested in Powerlifting so I did train the Squat and the Bench Press).
F = m.a
This was way back in 2008. Since then my views have changed and so have my lifts.
But the point is that here is what I did - and you should know that when I started "training" again, after that 4 month spell of sitting on my ass, I was still hurting and the injury was still prevalent and doctors had told me to be careful while lifting.
Well, to make things simple, Eric had me TOTALLY rework my technique. I had spent so much time Deadlifting incorrectly that when I started pulling the right way, it actually felt unnatural. Think of it like a bad habit. Once you have developed any bad habit it takes a long time to get out of it.
So, here is how it went (roughly)
Months 1&2: Worked in the range of 135-185 and did LOTS of reps and sets and what not.
Months 3&4: Worked within 185 and 235.
etc...
I spent time working within a weight range and I perfect that for quality, volume, intensity, whatever.
My point is, stop doing this whole 1 set is the only set I need to do BS.
Clearly you need to do more. So far everything you've done because some other authority figure has told you to do has proven itself to be generic advice not customized to suit your needs.
The exercises SouthernLord has listed above are EXCELLENT. You shouldn't do them in one day. They should be spread out on different days.
Do Pistols, Step ups and Lunges on one day in that order from the most complex movement to the easiest.
Do Overhead Squats with a Broomstick and Broomstick Squats on another day.
Here is a training template I used when I got back into lifting:
Deadlift Day
- Deadlifts - depending on what Eric wants me to do
- Bulgarian Squats 2x6-8
- Glute Ham Raises 2-3 sets
- Grip Work
Military Press Day
- Military Press
- Row Variant (Currently dumbbell rows)
- Press Variant (i rotate between flat db presses and uni shoulder presses)
- Tricep Exercise
Squat Day
- Squats 5x5 or 3x5, 2x8 or something. since we're not in any hurry for this i dont need anything set in stone
- Unilateral RDLs 2x6-12
- Regular RDLs 2-3x8-12
- Grip Work
Bench Press Day
- Bench Press maintenance work; Speed-Strength work @ 70-80% or 1,2,3,4,5RM testing
- Pull-ups Density Training
- Row Variant (barbell rows probably)
--x--
Look at my log which I linked above. I have everything I did to get back to Deadlifting. You should read up on it because it will help you and some things which occurred to me at the time will be recorded in that log.