Try this with a friend:
- Stand up facing them and grasp each others hands;
- Now perform abdominal hollowing – by sucking in your naval;
- Get you friend to shove in a random way and see how you are able to resist and balance;
- Repeat the exercise but this time brace – as if you are about to be punched.
- Compare the difference in stability.
By bracing you can resist the force and retain your balance more easily.
It is a commonly held belief that hollowing is the answer to core stability – much of the work focuses on transversus abdominus (TVA) muscle isolation using hollowing techniques with a view to stabilizing the lumbar spine. This view has stemmed from research on low back injury patients for whom TVA seems to lose efficiency. In this context TVA isolation with hollowing is effective.
However, as the image above tells us, the muscles of the trunk (‘core’) comprise more than just the TVA. Hence, if you are moving in a way that requires work against gravity ie walking running climbing crawling cycling playing tennis golf footy skiing etc.. then lying on your back on the floor recruiting only the TVA muscle will be of little use.
By practising abdominal bracing techniques you are activating tva, internal and external obliques, and rectus abdominus giving more effective support of the lumbar spine.
When hollowing the obliques are less active so lateral stability is reduced, and the tva is shorter thus less tension is created.
So the key here is unless you have a specific back injury do not perform isolation exercises to improve your core stability. Instead use exercises that require bracing the whole stomach and include the obliques…you could try bridge or plank variations as well as learning to ‘hinge’ and deadlift correctly – in all instances correct spinal alignment and breathing need to be a focus.