The prevailing general understanding of ergonomics is only limited to MSD, which is a quite limited and primitive approach. The circulation is at least as important to the health as loads are to the bones, muscles and ligaments, and it can be easily disturbed by poor circulation conditions.
It should, and advanced expert also use it to include the circulation or CD (circulation disorders). It emphasizes the disorders both in blood circulation and in the massive lymphatic system. It contains 300.000 -400.000 km of vessels, 10-15 liters of lymph liquid and 600 -700 lymph nodes that host immune cells (that kill pathogens), filter the wastes from the lymph liquid and interact actively with the blood circulation.
The other part of circulation is the blood vessels and blood. The circulation in blood veins is 75 % (3-5 l) of all circulation in blood vessels (4-6 l). Only 1-2 l of total 15 – 20 l of all free liquid combines combined, is pumped by the heart. Lymph liquid and vein blood flow, because of the movements of the body and the muscles create changes in the pressures in the soft tissues.
CD, disturbances in either blood or lymphatic vessels, is a very common health distractor. CD is mainly caused by the following factors
1. Pressure from furniture (the smaller area the better)
2. Angles of the knees and the hips (normal 90/90 is harmful)
3. Pressure from clothes (in traditional sitting clothes are too tight for optimum circulation)
4. Tensions in muscles (conventional sitting creates them in many muscle groups)
5. Immobility (as is the case in sitting lifestyle on conventional seats)
6. Flexibility of all connective tissues around all vessels (depends on lifestyle, nutrition, tissue health, age)
Picture: Sitting on a two-part saddle chair keeps you healthy and active.
Because circulation is very sensitive, even the smallest pressure can disturb it. We have the bodies of the stone age person, who was naked, never sat on anything soft and was frequently moving. Our conditions are totally different now and so we suffer from CD and also MSD a lot.
Salli seat design is based on sitting on the sitting bones, without pressure on the tail bone, pelvic floor or genital area, and only limited pressure on the inner thighs (where are also important lymph nodes). The upper body is in the natural standing posture, which keeps it active. Other improvements for circulation health are to optimize clothes so that they do not press at all (no pressure marks on the skin), maximize the breaks from sitting, move around during phone calls (walk & talk), and do certain exercises on brakes or talks (work & gym).
The optimum clothing helps circulation a lot. Next best solution to being nude is a short-trousers – overall on men and loose dress on women, both without any underwear. These solutions can function close to the same way as being nude.
There are seamless panties that leave no pressure mark for women. Men do not need underwear even for hygiene, if they wash their butts after toileting. A new design in trousers for women would have a small space between the sleeves under vulva for sanitary napkin taped on the trousers and thus eliminating the need for panties.
More ventilation in the genital area is surely a health bonus for men and women and can help to avoid many problems.
Other challenges are to design well-functioning and good looking circulation optimum clothes and get the health conscious audience to accept them for sake for the health, productivity and comfort.
Read research Loose-fitting underwear may benefit sperm production, Harvard School of Public Health.
Picture: Soft underwear together with two-part seats allow good ventilation without pressure on the genitals.