So usually my posts involve my training, but right now I want to materialize some of my thoughts on a subject I get asked about quite a bit, instability training. Now, over the past decade or so stability balls (aka Swiss balls) and BOSU balls have become quite the "in" thing with a lot of personal trainers. Hell, you see the vast majority of the general gym population using these things on a regular basis.
Unless these implements are used in a proper manner, you are just wasting your time. First lets look at risk(likelihood of injury) vs. reward. Utilizing BOSU and Swiss balls are supposed to provide an unstable surface to help with balance, coordination, and stabilization. they can when utilized as an implement, not a surface. Aside from aiding in ankle stabilization standing on these surfaces really does no good. In no way shape or form can you safely load yourself with enough resistance to elicit either a hormonal or a Central Nervous System response.
Let us take a look at an incident that happened at the University of Florida a few years back. Now, at a Division 1 collegiate strength and conditioning department they have the best equipment and some of the best strength coaches around. They had one of their basketball players doing dumbbell chest presses with a Swiss ball as the lifting platform. Now mind you, this is top of the line properly maintained equipment. As the player is about to lockout the chest press the Swiss ball bursts. His back hits the ground and not too long after his elbows hit the ground with the dumbbells still in hand. I've heard different accounts of how much weight he was using, but it was somewhere in the 80-100lbs range. As his elbows hit, the dumbbells continued to drive down and shattered both the Radius and the Ulna in both forearms. Can you say bye, bye basketball career. If that happens with a client, you have a substantial lawsuit on your hand.
So how can we properly utilize instability training? As I said before, use an unstable implement, not an unstable surface to hit the accessory muscles. Are you going to get more out a push up with the stability ball under your hands, or a stability ball under your feet? If you can actually think about what you are attempting to do in this scenario, the answer should be to keep the ball under your hands. "But Matt, you can engage your core and provide more unstable training for your core with it under your feet!" To which I answer, "Horse Shit!" Save your "core training" for when you actually want to train your core. Focus on what the goal of the exercise is supposed to be and don't try to kill too many birds with one stone.
This is where implements like Blast Straps, bands, and the TRX come into play. Want to test the accessory muscles of the shoulders during a push up? Ditch the balls and get some Blast Straps. Not only will you get more out of the exercise, but you don't to worry about your hands slipping off and having to pick bits of teeth out of your mouth. Want more? Look to Louie Simmons, one of the best in the strength business. His Bandbell Bar is amazing. By looping bands around kettlebells (you can use plates if you don't have kettlebells) and then looping it around the bar, you have made an unstable implement with a huge decrease in the risk of injury with all the benefit of training those accessory muscles. Try it, trust me you'll be shaking like a dog shitting razor blades. Try it with your squats, but use a regular barbell and you'll get the same results.
Now, I'm not saying that we should melt all Swiss and BOSU balls into bumper plates, though that would be nice. They still have a place to help increase range of motion and help adaptation in de-conditioned people. But, for the love of God, use them with some common sense.