When you injure your back people will often tell you that you have to strengthen your abdominals. If this is not explained correctly one would take this statement that you need to strengthen your stomach muscles by performing sit-ups.
The statement is correct but doing sit up while you have back pain will actually increase your pain considerably. What we mean is that you need to increase your Transverse Abdominus strength. This is a very deep muscle that directly supports your lumbar spine. People with lower back pain often have a very week TVA and therefore they have nothing to stabilising their spine when playing sports or when lifting for example.