5th December 2011
DID YOU KNOW THAT...
In 2007 and 2008 two RCTs were published by Tsao and Hodges that finally showed how we should try to retrain Transversus Abdominis (TrA) in people with back pain.
The first papers that showed that a timing delay in the feedforward properties of transversus abdominis was consistently linked to low back pain were published by Hodges in 1992-3. This timing delay is still the ONLY reliable and consistent pain related change measured in transversus abdominis.
However, the first RCTs to show what sort of retraining is able to result in a measureable improvement in this timing delay were published in 2007-8.
During the 15 years in between literally hundreds of different types of exercises were developed to train transversus abdominis … and in 2008 about 70% of transversus abdominis exercise used worldwide become invalid for correcting the timing delay.
The RCTs demonstrated particular exercises became ‘best practice’ to train recovery of TrA.
• Cognitive • Non-functional • Unloaded (low force + trunk supported) • Consistent (constant tension during relaxed breathing) • Isometric (static - without moving) • Low abdominal hollowing • Using feedback to monitor for
o a fascial response from TrA activation o without significant thickening of the other abdominal synergists (IO, EO, RA) o without movement of the pelvis or thoracic spine
Exercise that tries to activate TrA during movement and loading of the trunk, such as functional movements, low force core stability exercise and high force core strengthening exercise … do not change the timing delay in the short term.
These exercises have many positive effects (e.g. train the oblique abdominals to control painful rotation or extension) but they do not recover the pain related impairment in transversus abdominis.
Therefore, the recommendations for ‘best practice’ for recovering the TrA impairment in low back pain is to perform the non-functional low abdominal hollowing exercise to activate TrA and produce a ‘fascial corset’ response. BUT, do not move, or do functional activities, or loaded exercise (e.g. weight training or Pilates) at the same time. Hold the TrA exercise consistently during relaxed breathing for 2 minutes (e.g. 10 seconds x 10 repetitions) 2-3 times a day. Train in different functional static postures, with the trunk supported.
It is good to see that good research evidence is still updating and improving best practice.
References:
Tsao H, Hodges PW 2008. Persistence of improvements in postural strategies following motor control training in people with recurrent low back pain. J Electromyogr Kinesiol, Aug;18(4):559-6
Tsao H, Hodges PW 2007. Immediate changes in feedforward postural adjustments following voluntary motor training. Exp Brain Res, Aug;181(4):537-46
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