The Family Feud: TA Isolation vs Bracing
The rehab and fitness communities are in the midst of a little family fight over the work of two of our field’s visionaries; Paul Hodges, the grandfather of TA isolation and Stuart McGill, the um…step-dad of bracing. Despite our lack of conclusions or resolution internally, our private fight has leaked to the public in a NY Times Well piece. The tide seems to be turning against the TA (transversus abdominis) isolation programs sparked by Hodges work while McGill’s methodology of bracing the whole trunk is picking up momentum.
The Times article seems to support McGill’s position of whole trunk bracing over TA isolation, based in part on the cited British Journal of Sports Medicine (BJSM) study(a discussion piece based on the results of the original study published in the Journal of Orthopedic and Sport Physical Therapy (JOSPT)). But it’s worth taking a step back and a second look before kicking the elements of the inner core to the curb and running down another single-minded path. All my patients did TA’s too, but learning from our past mistakes and from all the available research will help us avoid another decade of running ahead of the evidence and allow us to implement mindful program-building.
The debate between the two camps -TA isolation versus bracing- is setting up a polarizing choice for practitioners. TA isolation relies heavily on one muscle and does not link to the inter-relationship that exists between all the muscles of the postural system. However, bracing ignores the sequencing of inner core component activation prior to outer core components that has been demonstrated in the literature.
The BJSM/JOPST study brought new understanding of how the TA activates. TA-based programs were historically developed around the idea (and the early work of Hodges) that the TA activated simultaneously on both sides of the abdomen before an arm movement began. Thus the “pull navel-to-spine” cue became a rehab and fitness mantra. However, the BJSM/JOPST study showed that the TA did not activate in the same way on different sides of the body. They found that the TA on the opposite side of the body from the movement (ex: left arm movement, Right TA) fired before the TA on the same side as the arm movement. (Nerd Alert: This is what physical therapists fight about – its no Jerry Springer, but it is important to how we build exercise programs). The authors of the BJSM/JOSPT study concluded that programs that elicit simultaneous activation of the TA on both sides of the body (“navel to spine”) may not mimic how the TA actually functions.
However, not mentioned in the NY Times article, is that the original JOSPT study found that the TA on both sides of the body still activated before all the other muscles studied. This continued to support the original concept of early TA activation understood through Hodges work. Without this critical piece of information a lay person or a pro might be misled. Also not recognized by the NY Times article is that the concept of bracing elicits a similar simultaneous activation of not one muscle but all of the muscles on both sides of the whole trunk. So here is the big finish: multiple studies, not just the one in the BJSM/JOSPT, have shown us that the trunk muscles respond differently depending on the demands of the task. The trunk muscles are an intricate system of checks and balances that create stability within the constant changes brought by movement. The trunk muscles do not have a uniform response to different tasks. Picking up a grocery bag and throwing a ball require a different sequence of muscle activation. However, both bracing and TA isolation train the trunk for a uniform response.
The NY Times article seemed to promote that the TA isn’t important. A better interpretation of the BJSM/JOSPT study is that the TA is smarter than we originally thought! It too has an adaptable response to the demands of the task AND yet it still fires first in the sequence of trunk muscle activation required to accomplish a movement task.
How we apply this understanding for more mindful fitness and rehab programs is our critical task as practitioners.
The clinical question is: TA or Bracing? How about neither! My beef with both ideas is the same – they advocate a static, simultaneous sustained hold at the center: a uniform response. Essentially activating a trunk isometric while performing peripheral arm and leg movements. An isometric is simply put: un-functional, the opposite of the growing trend toward functional patterning programs. What does a whole trunk isometric (bracing) or a TA isometric teach our clients about movement? About balance? About performance? Before we all jump from TA isolation to the bracing bandwagon, the most important question to answer is: Does a static hold train the trunk in the way that it actually produces central postural control within movement patterns?
Non-specific bracing seems to throw the baby out with the bath water. Is it wise to ignore the progress we have made clinically with the understanding of the existence of the inner core team (the TA has teammates: the Diaphragm, Pelvic Floor and Multifidus)? I am an old enough PT to remember the exercises we used to give out before core exercises existed…and they look a lot like the ones promoted in the NY Times article. Bird-dog (On all-4’s alternating a lift of opposite arm and leg) is not a new exercise. The understanding of neutral spine through McGill’s work is a major improvement on the old theme. But the resultant bracing program is familiar nonetheless . We all happily ditched similar programs when “core” hit the scenes, feverishly following the core path, because something was missing from those old low back stability programs. They didn’t totally hit the mark for our patients, either. Yet it seems we have come full circle again, rejecting one for the other.
So my question is this: Why the polarizing choice? The two systems co-exist in our movements, why shouldn’t they co-exist in our clinical and exercise programs. McGill reminded us that it takes a village to create movement. But let’s not forget that every village has a leader, that anchors the tribe and sets it’s course. Hodges introduced us to the leadership of the inner core, although in our excitement it seems we may have screwed up the secret tribal handshake with navel-to-spine. Programs that restore that leadership and involve the whole village will get the best result.
Those who forget the past are condemned to repeat it. Creating clinical models that are reflective of all the emerging evidence are critical to our evolving best practice.
Author’s note: I broke up with the TA as the leader of the inner core a while ago. I now teach programs that access the inner core through the dynamic relationship between the Diaphragm and Pelvic Floor. My caution to readers of the NY Times article is that although the TA may not the system entry point we thought it was, the function of the anticipatory inner core system is still critical to central/proximal stability. Linking a dynamic inner core (tribe leader) to the outer core (village) prepares the body to have the stability and flexibility to address the functional or fitness task at hand. Learn more here.
Check out Hodges (not interviewed for the NY Times Well piece) response to the debate here.
Julie Wiebe, Physical Therapist
Interior Fitness www.interiorfitness.com
Follow me on twitter @interiorfitness