The Principle of Specificity: Is there a training benefit when using unstable surface's such as Swiss/Stability/Bosu Ball

Swiss ball which is also called the Stability ball was originally created in 1960’s as a means to provide instability and resistance by challenging and engaging “CORE” muscles, therefore, improving balance, strength and flexibility. The use of stability balls started out in a clinical setting as a tool to rehab patients from injuries. Unstable surface training merged its way into gym settings and quickly gained popularity in the fitness world, as a means to build strength, flexibility, improve posture along with the excitement of exercise selection.
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Individuals looking to improve their posture, populations such as the elderly whose balance tends to decline due to lower muscular strength, those that have low back pain, limited range of motion, along with injuries that require rehab are some of the populations that will benefit from stability ball training. Including individuals that would like to improve their posture due to sedentary lives of sitting majority of the day, will benefit from swapping chair to stability ball in some cases. The instability produced will force you to fire up your “core” to maintain balance thus forcing your body to utilize muscles that have been forgotten due to inactivity with prolonged sitting and/or rehab of injuries. One of the benefits for the general population is to improve posture thus allowing your body to function more efficiently while putting less stress on your joints.

“A functioning core translates to a healthy back”

It has become more popular now days to utilize unstable surface training for HEALTHY ADULTS and ATHLETES. However, as with each piece of equipment and exercise selection there should always be a clear purpose on WHY, it is being utilized in your regime and prescribed program. The benefits along with limitations of functionality, must be accounted when choosing and/or prescribing exercise selections. If your main goal is to improve posture and balance utilizing unstable surfaces for strength training is a great tool, as long as you DON’T FORGET the MAIN PURPOSE, which is to target BALANCE.

Exercise selection with various accessories utilized for the purpose of balance is a “Skill-Specific” tool and should not be used and/or mistaken with the goal of strength training.

Strength training especially for healthy populations and athletes that DO NOT have posture and BALANCE ISSUES should be done on a FLAT STABLE surface to MAXIMIZE their STRENGTH and technique of the lift, rather than having the focus be shifted to balance. For example a squat or a bench press done on unstable surface has shown to affect the maximum isometric force output by 59.6% decrease (4) of the primary muscles utilized.
When choosing exercises, designing a programmer or even prescribing exercise selection you should consider at least 2 of the 7 principles of training and that is “Principle of Individuality-every person is unique and responds differently to the same stimuli due to influence in several individualized characteristics” and  “Principle of Specificity-to perfect a movement/activity you must perform the skill with proper body mechanics and technique” (5).  The importance of questioning one-self, as to the reason an exercise selection is being applied, will allow one to have a focused, efficient, and effective program without risking injury to the client.
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1.Willardson, J. M., The Effectiveness of Resistance Exercises Performed on Unstable Equipment. Strength and Conditioning Journal 2004, 26 (5).
2. Wahl MJ and Behm DG. Not all instability training devices enhance muscle activation in highly resistance-trained individuals. J Strength Cond Res 22: 1360–1370, 2008.
3.Nuzzo JL, McCaulley GO, Cormie P, Cavill MJ, and McBride JM. Trunk muscle activity during stability ball and free weight exercises. J Strength Cond Res 22: 95–102, 2008.
4. Anderson KG and Behm DG. Maintenance of EMG activity and loss of force output with instability. J Strength Cond Res 18: 637–640, 2004
5. Sands W.A, Wurth J.J, Hewit J.K. The National Strength and Conditioning Association’s (NSCA) BASICS OF STRENGTH AND CONDITIONING MANUAL

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