Risk Management, Portland, OR 05/16/2013
What Are You Sitting On?
Balls as Office Chairs
These balls (referred to often as Fit Balls, Swiss Balls, Physio Balls, Yoga Balls, or Exercise Balls) are a fitness and therapy tool. However they are not designed to be used as a chair for everyday office work. The Balls are highly effective when used in therapy for short periods of time e.g. 15 – 30 minutes.
Studies show the amount of electrical activity produced by skeletal muscles is very high while sitting on the Ball chairs. The result of this is the back muscle places a large amount of stress on the discs of the back. Continual contraction of this muscle decreases blood flow which can cause muscle spasms.
Like the rest of the muscles in the body, the ones that support your back also need rest between exertion to replenish energy and repair. Sitting on a an exercise ball for up to eight hours a day with little or no back support would not allow for proper rest and repair of the back muscles, which are in charge of holding the body upright while seated. On the other hand, ergonomic office chairs provide a full back rest that supports the “natural S-curve” of the spine effectively the entire seated duration.
Due to lack of education on their proper uses and the different types of balls available, there have been injuries resulting from the use of balls as an office chair. Lower quality balls have been known to wear down and pop. This sudden drop in air pressure causes the ball to instantaneously flatten, in turn causing the person sitting on it to fall and possibly injure themselves. Some effects from using a ball as an office chair are more long-term and may cause injuries related to repetitive use due to the total or partial lack of a back support.
Based on the potential for injury, and no ergonomic or medical support of the benefits of using the ball for long term seated work, the City of Portland does not recommend these balls be used as office chairs for seated work.
City Risk administers a citywide chair contract. There are many alternative chairs, which provide similar benefits to the ball. The following are some of the benefits offered by these chairs:
- The ability to control body movements and increase blood circulation.
- Lower body support when the user is in semi upright position.
- Open the hip joints, which allow the pelvis to remain in neutral posture.
- Retrains the body on how people should be sitting properly.
- Prevents hunched posture, improves posture and supports the upper abdomen and lower back.
- The sitting bones are supported by additional pressure sensitive foam.
- Can be placed in an open posture, which has the most ergonomic benefit.
- Some can be used as both stand stool and traditional chairs.
- One can be used for many sitting positions such as reverse position which is very good to support arms and chest.
- Some chairs mimic a horse saddle, which is the most active form of sitting.
- Reduced seated pressure by effective dispersion of body weight and pressure.
In addition, all chairs which are on contract with The City of Portland meet high ergonomic standards of performance, and employees have many choices in finding an ergonomic, fully adjustable chair which is designed to meet their unique needs.
If we are unable to fit the employee to a chair which meets specific medical needs, they will be referred to our vendor to be fitted to an alternative chair which can provide appropriate support. If you need additional information on ball chairs, please contact City Risk Loss Prevention at (503) 823-5101