Can an eccentric abdominal exercise improve abdominal hollowing?

We are now have reasonable evidence to assume that low grade inflammation influences muscle stiffness and hence, muscle tone. Since this finding, I have been using several exercises over the last few years to "load facilitate" the abdominals.

The first candidate was of course a primitive reflex. The Moro reflex - flexion phase was a prime candidate (Note as well the similarity between this and the popular "deadbug" - a popular "core stability exercise").

The next one I tried was loading through the hips with a bilateral hip flexion to about 75 degrees. I started using end range lumbar extension (anterior pelvic tilt) and monitored transversus with real time ultrasound. Indeed, many people had an ideal "corsetting" of the TrA. But unfortunately some others didn't. I tried doing this with flexion (posterior pelvic tilt) as well. My clinical reasoning was based on which direction of movement that provoked their symptoms. This did not work ideally since some people have multiple directions of poor movement. 

Since it may be that any loading would have similar benefits, I even tried the "hollow body". Again, this worked with some, but also seemed to make others worse. I tried abdominal bracing a couple of times, but it made them worse so I didn't try and more.

So out of these the Moro and the abdominal loading with bilateral hip flexion seemed best, but I was still looking for another option when these didn't work.

So I went back to basics and looked at an eccentric contraction. There is an older psoas major facilitation strategy we use in which we sit in neutral and lean backwards. For psoas we use the first 10-15 degrees, but I thought we could just continue as far as possible for the abdominals. Thus far, this seems to work the best. But there appear to be a few options to try.

Eccentric Abdominals

Sitting upright on the edge of a bed and feet on the floor

Slowly lean back as far as you can

Keep a straight back
Optional: brace heels on bed

Variation: Rotate trunk to one side and lean backwards

How am I judging improvement in TrA?

This is certainly an issue. The people who need (?) this exercise are extremely poor at any abdominal hollowing. 

Firstly, these people have been sub-classified as being able to learn. So I am not advocating these as a strategy to improve motor skill learning of abdominal hollowing. 

I am judging this by watching the TrA with RTU and making a judgement on the initial tension created by TrA. A secondary judgement is made on the general action of the muscle as it goes around the abdominal wall. This is sometimes referred to as the "corsetting" action, or as the "bending" around the back. This is very problematic to measure because it is moving in multiple directions at once and you have a 2D image. So I am only basing this on if I see this action or not. 

Lastly, I am asking people their sensation of effort in performing abdominal hollowing.

So in summary, one serious and largely untapped problem in low back pain is chronic low grade systemic inflammation. This is identified through the NICE-Symptom Screen. This is a major area in which subgrouping has missed. It can be a cause of behavioral factors, central sensitization, neurological factors and influencing muscle function. The physiotherapy profession needs to get to grips with this subgroup.

Unfortunately, there isn't a good clinical test for muscle tone (although we are working on two), but we certainly get a clinical sense if someone is low or high tone. It may be that any abdominal loading could show improvement in some people. We don't know that yet. 

In reality, the main mechanism of general exercise for LBP may be in its ability to provide some form of countermeasure for chronic low grade systemic inflammation.

Unfortunately, abdominal hollowing (TrA bias) has kind of gone out of popularity. Briefly, a couple of points. Yes, it has been improperly used and recommended. But that shouldn't negate the large amount of evidence to show that is is beneficial with appropriate subgrouping. A quick post on this was done...
https://www.linkedin.com/pulse/can-specific-motor-control-exercise-help-adults-pain-origin-gibbons/