I’m going to wager that you are feeling the « weakness » in your back from that « pull ».
Are you sure it was an erector? Could it have been deeper, like the QL?
In the mean time, I suggest you FOCUS your efforts on STRENGTHENING ALL of it.
Time on the back extension along with countless hours of GHR’s will certainly get you back to pounding the pounds.
For stretches, I’ve always recommended Joe DeFranco’s « Agile 8 ». It gets everything you need in one easy to remember program.
#1 – Foam Roll IT Band – Start just below your hip and roll up & down to your mid-(outer) thigh 10-15X, focusing on any tight spots. Then perform 10-15 “rolls” starting at your mid-(outer) thigh and rolling all the way down to the outside of your knee. Again, focus on the tight areas.
Foam Roll IT Band
IT Band Foam Roll (Beginning position)
#2 – Foam Roll Adductors – Start just below the crease of your hip and roll up & down to your mid (inner) thigh 10-15X, focusing on any tight spots. Then perform 10-15 “rolls” starting at your mid-(inner) thigh and rolling down to the inside of your knee. Again, focus on the tight spots.
Foam Roll Adductors
Adductor Foam Roll (mid position)
#3 – Glute/Piriformis Myofacial release w/ static stretch
#4 – *Rollovers into “V” sits – Perform 10 reps
#5 – *Fire hydrant circles – 10 forward circles/10 backward circles each leg
#6 – *Mountain climbers – 20 reps
#7 – *Groiners – Perform 10 reps. Hold last rep for 10 seconds…push knees out with your upper arms while dropping your butt down.
*The video below demonstrates exercises 4-7. Make sure you really focus on achieving a big range of motion with all these exercises. Don’t just go through the motions!
#8 – Static hip flexor stretch – Perform 3 sets of 10 seconds each leg. Perform all 3 sets on one leg before moving onto the other leg.
Static hip flexor stretch
I think if you go to YouTube you can see most of these if you put it in the « search ».
Especially exercises 3-7.