Related Videos: Lower Back Strain Video. Lower back strain is caused by damage to the muscles and ligaments of the back. Learn about muscle anatomy and the symptoms of lower back strain. Back Strains and Sprains Video. A muscle strain or a muscle sprain in the back is the most common cause of back pain. A muscle strain happens when the muscle is over-stretched or torn, resulting in damage to the muscle fibers (also called a pulled muscle). 2  A lumbar sprain happens when ligaments are stretched too far or torn. 3  Ligaments are very tough, fibrous connecting tissues that connect bones together.
The invalid SIM card error is typical of the type of error you get if your phone is locked to a different carrier than what you have. Many people offer unlocking service and typically charge between US $5 and $15 plus shipping to unlock your phone.he invalid SIM card error is typical of the type of error you get if your phone is locked to a different carrier than what you have. Many people offer unlocking service and typically charge between US $5 and $15 plus shipping to unlock your phone.
1 Restart your iPhone. 2  check for a carrier settings update. 3  Remove your SIM card from the SIM card tray and then put the SIM card back. 4  Make sure that the SIM tray closes completely and isnât loose. 5  If you use a SIM tray from a different model iPhone or from another phone manufacturer, it might not fit properly.f you get an alert about the SIM card in your iPhone. If you see an alert that says Invalid SIM or No SIM Card installed, follow these steps. 1  Make sure that you have an active plan with your carrier. 2  Update your iPhone to the latest version of iOS. 3  Turn airplane mode on and then off again.