Low back injuries are a common reason to visit the doctor and a health care professional like a physiotherapist.  People who have had low back injuries may have been told that they have to strengthen or retrain their core. The core is a group of 4 major muscles.  These include: transversus abdominus (TA), multifidus, diaphragm, and the pelvic floor.   The main function of the core is spinal stability.  Spinal stability refers to stabilizing each segment of the spine and is important for preventing low back injuries and helping with the recovery of a low back injury. Many back injuries cause these muscles to deactivate and spinal stability can be reduced.

The anatomy of the core is important for its overall function.  These 4 muscles come together in a corset like fashion to give us stability.  The transversus abdominus is the innermost abdominal muscle that wraps from the top part of the hips and lower ribs and attaches to the front of the stomach.  The muscle fibers are oriented in a transverse fashion giving this muscle its name.  Research has shown that the TA muscle is important for stabilizing the spine prior to movements of the arms and legs.  The TA muscle is active at a low level throughout the day. 

            The multifidus is a group of deep back muscles.   These muscles fill in some of the grooves in the spine and each multifidi spans several vertebrae.  The diaphragm constitutes the top part of the core muscles and the pelvic floor muscles are the bottom part of the core muscles.  The outer muscles are not part of the core and include the rectus abdominus and oblique muscles.  These muscles are important for overall movement and are often associated with the “six pack”.  Having strong rectus abdominus and oblique muscles doesn’t necessarily mean you have a strong core.

Often the transversus abdominus is the first muscle to work on with core stability. The TA muscle can be recruited by placing your fingers on your stomach, usually about 1” in from the hip and 1” down.  Patients are then instructed to slightly tighten or draw their belly button towards the bed or think about stopping the flow of urine.  You should feel a slight tension under your fingers.  Patients are encouraged to breath normally.  Typically this position is held for up to 10 seconds and often exercises are added to this to recruit some of the other core muscles.

Low back injuries affect many people at some point in their life.  The type of treatment a patient receives will depend on the nature of the injury and condition of the patient.  In many cases, exercises focusing on core recruitment or strengthening should be incorporated into the patient’s rehab.