Dr. Amar Gandavadi
PHD. Research physiotherapist with an interest in work related musculoskeletal disorders.
There has been much publicity recently about the danger to health of sitting for long periods. However, simply standing as an alternative may also have hidden health dangers. Perhaps the Bambach Saddle Seat represents a safe middle way?
Sitting has been described as a ‘natural human posture’ because it relieves the need to maintain an upright posture, and reduces the workload on the muscles and joints of the foot, knee, hip and spine. Sitting also helps with stability, so might help for tasks requiring fine or precise upper limb movements, and it’s better for tasks needing foot control. This may be why many dentists have changed from standing to sitting when they work.
Ordinary seat or Bambach Saddle Seat?
Sitting on an ordinary seat upsets posture. The 90° angle between the trunk and the thighs makes the pelvis rotate backwards, changes the line of gravity, and may create additional compression on vertebrae as the spine, pelvis, legs and feet are mainly supporting the body.
The abdominal muscles try to compensate, but this can compress the lumbar region. Muscle and ligament tension in the lumbar region, and the load on the spine and discs, may also be increased.
This is particularly true if sitting slumped, which may contribute to the development of problems such as:
• low back pain
• slackened abdominal muscles
• slumped spine
• impaired internal organ function
• swelling in the lower legs when sitting for longer than sixty minutes
More than 6 months of sitting slumped may lead to back pain because the muscles in the back which affect posture are used more.
On the other hand, sitting on the Bambach Saddle Seat helps you maintain a neutral (45°) hip position, so the abdominal and back muscles are balanced, which helps to maintain core stability.
When sitting is as good as standing
When standing, the spine is in its natural curved “S” shape, so the body’s centre of gravity passes through the lumbar vertebrae, trunk and feet, which means only minimal muscular activity is needed to maintain the posture. When standing normally, a vertical line drawn through the body’s centre of gravity would pass through the lumbar vertebrae, trunk and feet. The centre of gravity of the trunk, arms and head are all in line, and it only needs intermittent muscle activity to hold the trunk erect in the correct posture.
The design of a chair should aim at reducing the spinal load and maintaining the spine’s natural “S” shape, to reduce pressure on the discs and loads on the spine. The Bambach Saddle Seat does this, because sitting on it effectively simulates standing.
With the Bambach Saddle Seat, finding and maintain the right posture to ensure the right muscles are doing the work to maintain core stability is easily achieved, simply by adjusting the height and seat tilt. Research has also indicated that long-term use of the Bambach Saddle Seat reduces the amount of work the postural muscles have to do. After using the Bambach Saddle Seat for 3 months, some people have noticed their back feels as it would with poor posture on an ordinary chair, but after more than 6 months use, this decreases significantly.
Our bodies are designed to move, so staying in any one position for too long is not good for them. There is no right working posture, and it cannot be assumed that standing to work is good, as this may lead to problems just as sitting does. Also for some professions standing to work is simply not an option. It is important to achieve an optimal working posture, accompanied with regular rest breaks and chair-side exercises to help restore blood supply to the postural muscles.
Using the Bambach Saddle Seat with the seat height and tilt adjusted to suit the user, it’s possible to achieve optimal posture for working, and for reducing the problems which can be associated with standing, or sitting in an ordinary chair.
1. Grandjean E (1973) Ergonomics in the Home. London: Taylor and Francis.
2. Pottier M, Dubereuil A and Monod H (1969) The effects of sitting posture on the volume of foot. Ergonomics, 12: 753-758
3. Gandavadi, A (2008) Working Postures in Dental Practitioners and Dental Students: Relationships Between Posture Seating, and Muscle Activity. PhD Thesis, University of Birmingham, Birmingham, U.K, School of Health Sciences – Physiotherapy and School of Dentistry
4. Corlett, EN and Eklund JAE (1984) How does a back rest work? Appl. Ergon. 15: 111-14.