That is definitely a lot of questions going in multiple directions.
When you say “knot” can you feel a bulge or do you just feel the sensation of a cramp? What type of pain is it and exactly what movements cause the pain? Also is this “knot” close to the anterior or posterior side of your body? I am asking because it’s common to mistake QL pain for an external oblique or even part of the erector spinae group. You very well could have hurt the QL but it’s important to narrow it down if you want to attempt to rehab it and find the culprit. Another possibility could be the Latissumus Dorsi.
I have 3 thoughts and I’m thinking it’s most likely a combination of the 3:
- Tight errector spinae (which limits your ability to keep upright posture)
- Weak Core (I don’t doubt you have defined abdominals but unfortunately it doesn’t mean they are functionally strong for the amount of posture stability needed to perform bent over rows with heavy resistance).
- Weak retractors (particularly rhomboids and middle trapezius).
It’s fairly common to see a push vs pull imbalance in the upper torso in a dedicated lifter. It’s also common to see a flexion vs extension imbalance (in the back and hips) in a dedicated lifter. They tend to have a stronger anterior chain (anterior delts, pecs, quads, iliopsoas, etc) with the exception of the abdominals. Their posterior chain (hamstrings, glutes, erector spinae) are often not able to generate as much force and power and they are also not conditioned enough to maintain good posture and form.
When you are doing bent over rows, your erector spinae (3 long muscles running from the back of your skull all the way down to your pelvis) work to keep your back in extension as well as your spine in good alignment. The exercise you were doing has weight pulling in the opposite direction while your trunk is flexed over your body. This is an incredible amount of force for your erectors to take on.
NOW imagine on top of that you have weak scapular muscles which does not allow for the proper force development to be lifting 135 lbs towards your chest (which involves the middle trap and rhomboids pulling your shoulder blades closer together). If your shoulder blades aren’t retracting to their full capability, that means your lower back muscles do not have a good foundation for force development. They are too busy compensating for the weakness above.
So NOW we come to the QL. Keep in mind, this is a lot of speculating and I am by no means attempting to say this exact chain of events is what caused your QL to ball up in a little fist of fury. But if you are going to attempt to strengthen some possible weaknesses in this situation, the muscles above are what I would focus on. The QL is similar to the erector spinae in that it aids in extending the spine. It is a MAJOR postural muscle. It also is what keeps your pelvis aligned when you walk/run, and provides bilateral flexion of the spine.
One easy way to injure the muscle is if you are positioned in trunk flexion and trying to maintain that posture while bearing a load and turning/twisting. My reasoning for thinking the shoulder retractors may be part of your problem is because once they tire out during your rowing movement (usually one side tires quicker than the other) it’s going to place an imbalance on your spine. What is the first back extensor muscle that will most likely be stressed by this imbalance? The QL. So you might not have felt like you were ACTUALLY twisting while you were doing rows or turning to one side, but the weakness up above was enough to place a different type of force through your QL.
Again, I don’t want to cover every scenario. It could be endless. If you went to a chiro and they told you they thought they new the exact problem (or a PT) they would be full of sh*t. You can’t know exactly what happened, but you can be proactive which you seem to be. Your questions are all important.
So…if I had advice…
I would do a lot of core work (particularly stiffening around the spine and endurance based exercises with breathing). I would stay away from exercises that place your trunk into flexion (ESP CRUNCHES). I would also work on slowly incorporating more retraction exercises for your shoulders to strengthen that area.
Because the QL is a postural muscle, you are always using it. I would stray from any exercises involving side bending for awhile. Isometric holds (like planks) are perfect as long as it does not get noticeably tighter. Working on slow,deep breaths during the plank holds will create a much bigger stiffening affect around your spine than if you were to just hold your breath or breath lightly. If the planks make your QL then just be patient and wait a few days/weeks. It will respond to rest. The one other thing I have found that works wonders on a tweaked back/postural muscle is an E-stim machine. They are anywhere from $30-$1000 dollars if you search online. I picked up a great one on Amazon for 60$ when I pulled an intercostal and couldn’t get the muscle to un-knot and calm down. It helped immensely.
Hopefully some of this is helpful.