Our abdominal muscles (or Abs) play a big part in our core muscles. They aren’t the only part but they are a piece that makes up the whole. It requires coordination of each of the different muscle groups to help create a stable foundation so that we can move our arms and legs effectively.
What do I mean by eccentric abs? Well when a muscle contracts it can do it a few ways. One of those ways is eccentrically. This post about squatting helps to explain the difference between eccentric and concentric muscle control. But basically, eccentric contractions, or slow lengthening of the muscle, helps to give us control.
When we do sit ups we are asking our abs to perform concentrically, or to shorten. When we do planks, we are asking them to perform isometrically, or to stay the same length to hold us stable. So when do we work on them eccentrically, and why is this important?
Well we use our abs eccentrically also. We use them to help us control our movements. Think about balance. If you get bumped and your top half is moving backwards, you want your abs to be slowing that movement down until they can use a concentric contraction to bring you back up to midline. When I started thinking about this, I started wondering how I could help kids practice eccentric control. For our quads (leg muscles) its easy, we practice slowly sitting down in a chair, or do squats, or slowly step down from a step. If we ask people to slowly lower down from a sit up position, they will definitely work on it some, but chances are they are going to use their hip flexors (the front of their hip) to help control. Especially, if its a child and they need us to stabilize their legs.
So, how do we focus on the abs and not get primarily the hip flexors? Well one way we came up with was doing a ball pass. This can be done in sitting, standing, high kneeling, half kneeling, or whatever position you want to try where the trunk is upright. Make sure the child is guarded properly to maintain safety, and then have them reach back over their head with both hands to get a ball from someone behind them. They can then throw the ball at a target in front of them. After you do a bunch of repetitions this way, have them start with the ball in their hands and then lean back to try to drop in in a basket behind them. Not only will this engage their abs, but they will also get to work on balance in whatever position you have them in.