The Value of Unstable Training?

It's very common place to see unstable training devices in the gym these days. BOSU's, Stability balls, dyna discs etc are examples of devices that are used with this method of training.

The rationale for using such devices is to provide an unstable surface for the upper and lower extremities so that there is an increase in stabilizing muscle activation and proprioceptive demand on the patient or client. Note...I wrote patient first. Unstable training originated in the physical therapy clinic as a way to rehabilitate an injured limb to meet the demands of everyday life. It soon found its way into the fitness arena where it is now the norm to see healthy people using these devices.

The question remains...does research back the assumption that more stabilizing muscles are activated during unstable surface training?

In an article that was published in the May 2007 edition of Manual Therapy, graduate students of Canadian Memorial Chiropractic looked at EMG activity of the scapulothoracic (shoulder blade) muscles when perfoming a pushup on a Swiss Ball with their feet on a bench. A pushup with a plus was also evaluated with hands on different support surfaces.

The results demonstrated that there was no statistically significant difference between placing the hands on an unstable vs stable surface. What was found to have a greater affect in activating the scapulothoracic muscles was foot position. Elevating the feet above the hands had a greater influence on the shoulder stabilizers vs the Swiss Ball.

What to draw from this? Often times we rely upon anecdotal information as a rationale for making exercise choices. This article is an example of what we have always thought to be true may not necessarily be the case. In my next post I will look at the differences between balance and stability training...does the research back up the prevailing philosophy found in the fitness setting?