What are the main problems resulting from unergonomic sitting?
Sitting in an unergonomic way, especially for long working hours, causes the overexertion of many elements of the musculoskeletal system. The most important condition concerning people who work in seated position are problems with the lumbar spine , which supplies innervation for the pelvis and lower extremities.
Role of the chair for the functioning of the body
Stools which are currently popular have hard, unadjustable seats and backs. It causes the retroposition of the pelvis and, consequently, lesser lumbar lordosis (the natural curvature of the spine), which leads to a massive overexertion of bones and tissues. It starts with strong tension of the back muscles, slouching, and leads to pain. This position encourages disc protruberance. The force operating in particular segments of the spine causes protrution of the discs, increasing the risk of their contact with nerve roots. The effect of this process is immediately felt in the form of pain, wandering from the lumbar spine , through the buttock, down the leg. – depending on the innervation area, sciatica appears.
A hard chair and inappropriate length of the seat can contitute an additional factor irritating the area of the sciatic nerve or ischial tuberosity. It may cause a great discomfort resulting from the tension of the gluteus muscles, hamstrings in the back of the thigh and pain radiating down the leg, similarly to the sciatica symptoms. This condition is called the piriformis syndrome, when the piriformis muscle is tense and irritates the sciatic nerve.