Stability Balls, Wobbles and Bosu balls
Unstable surface training. What is it? What does it mean and what are the pros and cons?
Unstable surface training has become very popular in the gyms and with personal trainers everywhere. Everywhere you look you see people performing balancing acts worthy of Cirque de Soleil.
Unstable surface training may involve equipment such as wobble or balance boards, bosu balls, stability balls and 1/2 foam rollers. I am sure that you can pick up any magazine on fitness or even sport training and come across a picture of someone squatting on a stability ball or standing on a bosu doing shoulder presses, or bicep curls.
However, you need to ask is it safe, beneficial or getting you closer to your goals.
There are certain times during rehabilitation when using unstable surface training is necessary and recommended. This should be for individuals who have suffered an ankle or knee injury. Working on an unstable surface such as a wobble board has been shown to help restore proprioceptive and nervous system reaction deficits. In other words, it helps re connect the nervous system and the muscular system to regain proper movement patterns.
Using unstable surface training in the hopes of increasing strength is not the most productive method. In a study done by Anderson and Behm, maximal isometric force output with the unstable chest press was significantly lower (59.6%) than in the stable condition. (1) What this means is that if you are going for strength gains, keep the exercise on a stable surface such as a bench.
Chest Press on a stability ball may be used to incorporate core stability work, but the weights used should be submaximal or higher rep range loads. Stability ball presses should never be used with maximum weights.
What about core muscles and their activity during unstable surface training? A study by Nuzzo, McCaulley et all concluded that activity of the trunk muscles during squats and deadlifts is greater or equal to that which is produced during stability ball exercises. It would appear that stability ball exercises may not produce a sufficient stimulus for increasing muscular strength. (2)
Everywhere you look in gyms and personal training studios, you will see a variety of equipment designed for unstable surface training. There are numerous tools in a trainers “toolbox”. All of them may be appropriate for certain clients at certain times. But, the question must be raised first – is it applicable to this situation? Is it beneficial to the clients’ needs or is the latest youtube creation.
You must ask what the purpose is of standing on a stability ball or bosu ball performing a weight exercise?
The goal of the bicep curl for example is to build strength or mass or both. Standing on an unstable surface will limit the amount of weight that is able to be utilized without losing one’s balance. If you are attempting to solicit a neuromuscular response with balance and stability, there are more appropriate ways to do that. Single leg training for example.
Unstable surface training may have some merit with untrained individuals and in some rehabilitative situations, but as with any training tool their application must be carefully considered and applied.
Till next time,
(1) Anderson K. G. and Behm, D.G. Maintenance of EMG Activity and Loss of Force Output with instability. Journal of Strength and Conditioning Research, 2004 (18) 637-640
(2) Nuzzo, J.L., McCaulley, G.O., et al Trunk Muscle Activity During Stability Ball and Free Weight Exercises. Journal of Strength and Conditioning Research, January 2008. Volume 22, Issue 1, pp 95-102