Most commercial flights, however, fly at 38,000 feet above the Class B maximum height and there is not a specific speed limit imposed. BA Captain Dave Thomas stated why they fly at this height: 'This sort of altitude is a good compromise between engine efficiency and aerodynamic efficiency for jet aircraft.
The most common cause of de Quervainâs tenosynovitis is chronic overuse of the wrist. Repetitive movements day after day cause irritation and pain. One common movement that causes it is lifting a child into a car seat. Another is lifting heavy grocery bags by the handles.
The exact cause of Guillain-Barre syndrome isn't known. The disorder usually appears days or weeks after a respiratory or digestive tract infection.Rarely, recent surgery or immunization can trigger Guillain-Barre syndrome.n AIDP, the most common form of Guillain-Barre syndrome in the U.S., the nerves' protective covering (myelin sheath) is damaged. The damage prevents nerves from transmitting signals to your brain, causing weakness, numbness or paralysis. 1  Symptoms. 2  Risk factors.