Brazilian Jiu Jitsu

Does rectus abdominis assist with core stability and your brazilian jiu jitsu?

In theory no, every anatomy book and article I’ve researched suggests that rectus abdominis is a trunk flexor and trunk lateral flexor only, however from my personal experience of lifting weights and from testing individuals whose training I’ve been involved in, it would appear that rectus abdominis does contribute to core stability but only under more extreme conditions. I tested two individuals on a squat and deadlift.  Brazilian jiu jitsu 

The resistance lifted was a 12 RM, 6RM and a 3RM with 3 minutes rest between sets (RM is repetition maximum brazilian jiu jitsu
E.g. a 6RM is a weight that can only be lifted six times).

While the individuals attempted their 12RM, 6RM and 3RM of the squat and deadlift I stood behind them and pressed my hands against their stomach to feel the contraction of rectus abdominis.
With the 12RM there was hardly noticeable change to the tension of rectus abdominis.
With the 6RM there was some contraction of rectus abdominis.
With the 3RM there was definitely a strong contraction of rectus abdominis, which is good for brazilian jiu jitsu

The reasons for the isometric contraction of rectus abdominis under load I can only speculate. It’s possible that because rectus abdominis covers a large portion of the anterior (front) section of transversus abdominus, under more extreme load rectus abdominis contracts to give transversus abdominus a firm base to contract against (similar to a weight lifting belt).

Another reason for this theory is the thickness of transversus abdominus varies as it wraps around the trunk, the thinness portion of transversus abdominus lies directly beneath rectus abdominis. It’s also possible that under extreme load rectus abdominis contracts isometricly to press against transversus abdominus which in turn builds up even more internal pressure.

 

Brazilian Jiu Jitsu