Unilateral training is one of the best ways to improve limb strength and correct gross asymmetries. However, some of the exercises I see performed end up looking more like a circus act instead of a way to spur real physical adaptations. What ends up happening is overthinking on the coaches part, trying to concoct some magical exercise that will fix ankle issues, shoulder pain, take back the iron throne, and cure cancer. Okay, maybe I’m exaggerating a bit but really, some of these exercises just make me wonder what the actual goal of them is…
Half the time, instead of properly executing whatever they’re asked to do, they end up flailing around one leg just trying to stay upright while one arm does one thing and the other is doing something else. Or the athlete gets so close to a wall that any stability adaptations the coach was looking for has been negated because they're using so much external support to accomplish the exercise.
For me, stability isn’t so much about balance, and challenging it with different types of arm movements, but rather it’s about preventing unwanted motion through the ranges of motion that are important for the athlete. So in my eyes, one of the best ways to train stability, and in turn improve balance, isn’t by taking away support, but instead by adding strength to the athlete, and helping them feel connected to the ground by improving foot and ankle function. You see, by increasing muscle strength we are better able to control our moving limbs, as well as the stance leg which in turn increases balance. Coordination and spatial awareness obviously play a role here, but in healthy athletes these aren’t normally the limiting factors.
And just to be clear, yes there will a time when support has to be taken away to further improve stability, but this should be done progressively, and only to an extent that doesn’t force the athlete to be falling over every few seconds. When the primary demands are on trying to find balance and stay upright, you start to sacrifice any improvements you could make in strength or power, which are more important for success in my opinion.
Ultimately, it all comes down to what the goal is. If you want to improve unilateral strength, then don’t add excess fat to the basics such as single leg squatting/hinging. And if the goal is to increase stability, then you need to first find out how much is necessary, and how much do they currently have before you can select exercises that are appropriate and will lead you to the athletes goal. More often than not, they won’t need much “balance” work, but rather will need to improve the strength of the muscles used.