Why work in a static position is harmful and what health problems can it cause?
The human body is not designed to maintain the same position for a long period of time. Immobility more than 8 hours a day slowly leads to severe musculoskeletal problems. Some muscles are overloaded while others are overrelaxed. This causes a disballance in the muscle strength. For example, prolonged sitting position weakens the rear cervical muscles while overloads the front ones, weakens the back and overloads the chest muscles, weakens sacrum while overloads the abdominal muscles, gluteal muscles weaken. Maintaining the same position for a long time is detrimental to the flexibility of the spine. The chronic overload of particular muscles and the patterned movements transmit the load from muscles and tendons to the bones and even to the internal organs. The bones get exhausted. The prolonged posture of your body tilted forwards leads to excessive load to the intervertebral discs. This causes changes in their structure and subsequently to a discopathy or even a herniated disc. In all these conditions the main symptom is pain (in the neck, back, waist). It can be localized in certain points or irradiated. There is a morning stiffness, numbness of the limbs. The unnatural hand position and the patterned movements (eg when using the computer mouse) lead to inflammation and swelling of the tendons of the short and long tensor of the fingers. It increases the pressure in the closed tunnel in the middle of the wrist called “carpal tunnel”. Since there is the medial nerve passing through this tunnel, the result is numbness and tingling of the first three fingers of the hand, which it innervates. First a pain in the night or early in the morning occurs. Later on a weakness in the hand and the base of the thumb appears. Patients begin to drop small objects, feel difficulty in opposition of the thumb to other fingers and so on.
Inflammation of the tendons of the forearm and their sheaths (tendinitis, tenosynovitis) are also among the diseases caused by prolonged static load of the arm and making stereotyped movements with a small amplitude. The symptoms are pain and swelling in the affected tendon. While moving the wrist and fingers a screeching sound can be heard. The skin above the tendons is flushed, the movements are severely restricted. This particular condition is called De Quervain (stenosing tendinitis of the long abductor and the short extensor of the thumb). In the past it was known as “washerwoman disease”. Now it is one of the most common “office diseases.” It is characterized by acute pain along the tendons of the thumb. Sometimes in palpatory examination a small nodule can be felt.
Tennis-elbow (lateral epicondylitis) is also among the diseases caused by prolonged static position or patterned movements of the rotators of the forearm. Although the disease is known as “tennis-elbow” not only the tennis players suffer from it. The pain might be caused by certain movements or it can be constant. It may be localized in certain point, or it radiates to the wrist. There is a swelling in the elbow and the forearm. The grip weakens, sometimes the range of motion in the elbow joint is limited.
Although not often, the static load of the upper arm results in periarthritis of the shoulder joint. The symptoms are inflammation of the soft tissues around the joint (muscles, tendons, bursae) and pain (mostly at nigh). There also is a limit of the range of motion in the joint (mostly at the abduction and rotation). If the condition is left untreated, the complaints become more serious and the limitation in the range of motion of the shoulder increases. This state is known as “frozen shoulder”.
Inflammation of the shoulder plexus (Plexitis) can also be resulted by prolonged static load of the upper arm. Adding to that the cool stream of air conditioners and open windows in offices the condition becomes more and more serious. The pain is spontaneous, burning and is located in the middle of the shoulder blade, shoulder or arm and goes all the way to the fingers. The upper limb may be numb and stiff.