The Swiss ball, is also known as physioball, balance ball, birth ball, body ball, fitness ball, gym ball, gymnastic ball, Pilates ball, Pezzi ball, sports ball, stability ball, Swedish ball, therapy ball, or yoga ball. This ball is constructed of elastic soft PVC with a diameter of approximately 35 to 85 centimeters (14 to 34 inches) and is filled with air.
The Swiss ball was developed in 1963 by Aquilino Cosani, an Italian plastics manufacturer. These balls, then known as “Pezzi balls”, were first used in treatment programs for newborns and infants by Mary Quinton, a British physiotherapist working in Switzerland. Later, Dr. Susanne Klein-Vogelbach, the director at the Physical Therapy School in Basel, Switzerland, popularized ball exercise as physical therapy for neuro-developmental treatment as well as for adults with orthopedic or other medical problems.The term “Swiss Ball” was used when American physical therapists began to use those techniques in North America. From their development as a physical therapy tool, those exercises are now used in athletic training, fitness and more alternative exercise routines such as yoga and Pilates. Although the Swiss ball has been popularized by many and is used to obtain a variety of goals, very little research has shown its proven benefits.
A new study was recently published in the Journal of Orthopedic and Sports and Physical Therapy by Rafael Escamilla to assess core muscle activation during Swiss ball and traditional abdominal exercises. This is a great research topic as the Swiss ball is widely believed to enhance core muscle activation as the thought process is that when you expose the body to an unstable environment, reflexively it will try to stabilize itself against it. Think about it this way, when you walk on ice with flat shoes you reflexively stabilize yourself so you don’t fall. In Sum: exposure to instability forces stability.
As many of us have poor trunk stability and exhibit movement dysfunctions associated with that, Swiss ball exercises make perfect sense don’t they? As I said above, exposure to instability = Swiss ball, forces (trunk) stability. The problem is though that often people think that the more difficult the ball exercises are, the better they should be, right? These individuals create new exercises that are difficult and promote them as new “functional” exercises without any efficacy or research validation. Fortunately, articles like the one below help us select the most appropriate exercises for the goals we try to obtain. For example, doing one arm presses on top of a Swiss ball is not the most productive exercise to strengthen your shoulder.
In the Raphael Escamilla study, exercises on the physioball included the pike, knee-up, skier, decline push-up, hip extension, roll-out, and sitting march. These were compared to the traditional crunch and sit up floor exercises.
The muscles examined in this study were the upper rectus abdominis, lower rectus abdominis, external oblique, internal oblique, lumbar paraspinals, latissimus dorsi, and rectus femoris.
- The pike and roll-out were the most effective exercises in recruiting core musculature. These exercises are pretty advanced and may thereby be more appropriate for the advanced patient or client.
- The pike, roll-out, knee-up, and skier exercises all showed relatively high EMG activity compared to the crunch and sit-up exercises. These exercises also had high EMG activity of the latissimus and internal oblique, suggesting that these exercise may be good exercises to enhance core stability by tensioning the thoracolumbar fascia.
- The decline push-up and hip extension exercises produced similar amounts of rectus abdominis, external oblique, and internal oblique activity compared to the traditional crunch and sit-up. This is interesting considering that these are upper and lower extremity exercises rather than what would be considered “core” exercises. Here is a great example how the use of a physioball increases the contribution from the core.
- In Sum, no statistically significant difference in rectus adbominis activity was observed between the two traditional crunch and sit up exercises, however rectus femoris was significantly higher during sit ups. While this info is not new, it does continue to demonstrate that crunches should definitely replace sit ups in any training or rehabilitation program, especially when considering the greater intradiscal pressure and lumbar compression observed with the sit up.
Of note, the authors highlight the potentially disadvantageous stress at the lumbar spine during hip flexion activities. This needs to be taken into consideration when designing exercise programs. People with lumbar disk pathology may want to at least initially avoid exercises that involve hip flexion, such as the sit up, skier, knee-up, and pike. More appropriate exercises may be the roll-out, decline push up, and crunch.
As you can see, choosing core exercises is not a simple task. There are several factors that need to be assess in each individual. This article examined EMG activity, but the authors do a good job relating the info to core function in the discussion. The way I see it, we need to take 5 factors into consideration when designing core programs:
- Image Pathology/function of the person – Injured and healthy people have two different challenges and goals for core stability. The same program will not work for both.
- EMG activity of core musculature,
- EMG activity of surround musculature – especially the rectus femoris and psoas,
- Position of the lumber spine during exercises, and
- Function of the core musculature during movement – i.e. does the exercise produce an isometric stabilizing force or does it use concentric/eccentric forces to control core movement.
Research on Balance and Stability
Common sense tells me that training on unstable surfaces does not make sense for healthy athletes. For some reason, unstable surface training made the jump from the rehab setting to the athlete conditioning realm. Common sense aside lets look at what recent research has proven.
In a paper by J.M. Willardson, Core Stability Training: Application to Sports Conditioning Programs, he appropriately comments that, “Despite the popularity of core stability training, relatively little scientific research has been conducted to demonstrate the benefits for healthy athletes.” He quotes findings by authors of studies such as Vera-Garcia and Behm that indicate that the abdominal region of the body experiences greater muscular ‘activity’ during exercises on unstable apparatus such as a Swiss ball as compared to a stable weight bench. My response to such findings would be, “Is this type of muscular activity producing a useful adaptation for sports and, for that matter normal human activities such as walking, standing, jogging and picking up something off the floor?” I know that when I sneeze or cough my abdominal area experiences significant muscular ‘activity’. A friend of mine even broke a rib during a coughing fit (not recommended). Following from the pro-Swiss ball perspective, should we then encourage athletes to start smoking and inject them with the cold virus? We could probably get financial support from tobacco companies and the producers of Nyquil with this training approach.
Behm and associates also found out that force output was less on unstable apparatus versus stable benches. Wow – we had to perform a scientific study to determine that outcome! Just go check out your local gym where the fitness crowd is performing dumbbell presses on Swiss balls with the 10 and 15 pound dumbbells. That’s okay – you won’t find me on that end of the dumbbell rack anyways. Willardson again appropriately states that while core stability is required for successful execution of sports skills, “very few sports skills require the degree of instability inherent with Swiss ball exercises.” He goes on to quote Stuart McGill who indicates that, “Any exercise that channels motor patterns to ensure a stable spine, through repetition, constitutes a core stability exercise.” So, from my perspective, this would include standing, walking, running, jumping, weight lifting, throwing, playing sports and so on and so forth.
Behm and associates also looked at wobble boards and ice hockey performance. For some reason, people associate balancing on a fulcrum board with slipping and sliding on ice. Good thing those people aren’t helping design automobiles and snow tires. Behm and associates found out that, “for the most skilled players, skating speed was not significantly related to wobble board balance (R= -0.28). Once again, I guess we needed a scientific study to figure that one out! Apparently, common sense is not so common. Willardson goes on to state something that every good coach and trainer should figure out before they provide a training program for hockey players – “The optimal approach to improve balance for healthy athletes might be through practice of relevant skills and movements on the same surface on which those same skills and movements are performed during competition.” Hallelujah!!!! I think we are on to something here. You won’t get a standing ovation at a conference for this, but hey, you’ll be doing the industry and your clients a service.
What’s worse: the board or the socks?
Here’s a good one. Stanton and others, as identified in Willardson’s article, evaluated Swiss ball training for improvements in running economy and VO2 max. They found out that Swiss ball training yielded no significant differences in these running performance indicators. Once again… no kidding! The funny part is that they concluded that the best type of core strengthening for running would be, “exercises performed in a unilateral, single-leg support, standing position, with the arms held in a position similar to running.” My oh my, those exercises sound like – you guessed it – running. You mean to tell me that actually running will condition my ‘core’ to the demands of running? Get outta here!
Stanton and friends also concluded that, “Improvements in core stability were skill specific.” This is something I have always told my athletes. Performing repetitions on a Swiss ball, Bosu trainer or balance board will improve your stability on these devices. But, there is little to no transference to high speed, forceful and dynamic movements on solid ground, or even ice for that matter. It is similar to using the juggling of balls as a training activity for improving hand-eye-coordination. It will make you better at juggling balls, but it won’t prepare you for catching a 100 mph fastball. Remember “the body will respond placed to the forced placed upon it”? Let’s expand that to the central nervous system: “the central nervous system will respond placed to the challenges placed upon it”.
For those who are willing to listen to reason, the best way to address the core strengthening requirements for running would be to:
- Run (yes, it’s that simple).
- Perform the marching, skipping and high knee running drills we should have all learned as young athletes.
- Low amplitude jumps and plyometrics which load the core vertically, similar to running.
Of course, as supplementary exercises, you can continue to perform your med-ball passes and abdominal crunches. Do you need to be ‘unstable’ while doing these types of exercises? There will always be a small degree of balancing going on while performing these types of exercises, but not to the degree that your well-being is at risk (i.e. falling off a Bosu or Swiss ball). A good solid surface should serve you well.
Attack of the killer Swiss Balls” or “Functional” exercise?
In the paper by Behm and Anderson, The Role of Instability with Resistance Training, they conclude that, “…both stable and unstable exercises should be included to ensure and emphasis on both higher force (stable) and balance (unstable) stressors to the neuromuscular system.” My problem with this statement is that the term “unstable” needs to be appropriately defined and a magnitude attached. I would take the term ‘unstable’ to mean performing a standing, single-arm shoulder press (on solid ground) over a seated barbell bilateral shoulder press. However, others might conclude that “unstable” means performing a single-arm dumbbell snatch on a Bosu ball while in a canoe surrounded by alligators. You might go as far to deem the person performing this exercise as both physically and mentally unstable.
Cressey, West, Tiberio et al. also found similar results with athletes performing exercises on stable surfaces outperforming those who trained on unstable surfaces (inflatable disc) in activities such as jumping, sprinting and agility. As with other studies, they determined that force application was not nearly as high on unstable surfaces as compared with stable surfaces. Translation: When your body senses you could possibly fall over, it doesn’t allow you to put heavy weights over your head. It’s really all about self preservation.
So the research is in and it shows that balancing on different unstable devices yields no significant improvement in athletic ability. I’ve gone through at least a dozen studies and the results are pretty much the same. I hope more researchers don’t continue to waste their time studying this fact of training.
Pets starting Bosu training…
So what can we do to improve the situation? The answer is – you guessed it – education. Every sporting coach and strength coach must go back to the fundamental biomechanical requirements for different movements and sports. Specificity of training is important. This includes specificity of movement, specificity of load, specificity of velocity, specificity of contraction type, specificity of joint angle, etcetera, and etcetera. However, trying to simulate sporting movements by creating artificial environments and over-thinking the equation in an effort to sell products is irresponsible. Hopefully the masses will be enlightened sooner than later.
- Core Muscle Activation During Swiss Ball and Traditional Abdominal Exercises
- Standing Single Arm Presses on the Stability Ball
- Anderson, K.G. and D.G. Behm. Maintenance of EMG Activity and Loss of Force Output with Instability. Journal of Strength and Conditioning Research, 2004, 18(3), 637-640.
- Behm, D.G. and K.G. Anderson. The Role of Instability with Resistance Training. Journal of Strength and Conditioning Research, 2006, 20(3), 716-722.
- Behm, D.G, K.G. Anderson and R.S. Curnew. Muscle Force and Activation Under Stable and Unstable Conditions. Journal of Strength and Conditioning Research. Journal of Strength and Conditioning Research, 2002, 16(3), 416-422.
- Carr, Gerry. Sport Mechanics for Coaches. Human Kinetics, Champaign, Illinois: 2004.
- Cressey, E.M., C.A. West, D.P. Tiberio, W.J. Kraemer and C.M. Maresh. The Effects of Ten Weeks of Lower-Body Unstable Surface Training on Markers of Athletic Performance. Journal of Strength and Conditioning Research, 2007, 21(2), 561-567.
- Hamlyn, N., D.G. Behm, and W.B. Young. Trunk Muscle Activation During Dynamic Weight-Training Exercises and Isometric Instability Activities. Journal of Strength and Conditioning Research, 2007, 21(4), 1108-1112.
- McBride, J.M., P. Comrie and R. Deane. Isometric Squat Force Output and Muscle Activity in Stable and Unstable Conditions. Journal of Strength and Conditioning Research, 2006, 20(4), 915-918.
- Stanton, R., P.R. Reaburn and B. Humphries. The Effect of Short-Term Swiss Ball Training on Core Stability and Running Econonmy. Journal of Strength and Conditioning Research, 2004, 18(3), 561-567.
- Willardson, J.M. “Core Stability Training: Applications to Sport Conditioning Programs.” Journal of Strength and Conditioning Research, 2007, 21(3) 979-985.