If you have chronic pain or recurrent injuries, you may not be addressing the core of your problem
The core operates in conjunction with the extremities as an integrated functional unit, which enables force production (a concentric contraction), force reduction (an eccentric contraction) and dynamic stabilization (isometric contraction) against external forces.
Many people who suffer from chronic pain or recurrent injuries lack optimum core strength. This is perpetuated by postural strain from our jobs or lifestyle as well as common exercises that many people perform using machines or movements that stress one plane of motion, which over time leads to imbalances.
A common example is individuals who sit for long periods at a desk job working at a computer with poor ergonomics. This position relatively shortens the hip and shoulder flexors and consequently lengthens the hip and shoulder extensors. This is compounded when these individuals go to the gym after work and use cardio and weight machines that primarily work in the sagittal plane (which most do), e.g. recumbent bike, elliptical, seated pushing and pulling machines and the ab machine (sit-ups or crunches can also be problematic).
The combination of the visco-elastic nature of soft tissues (muscles, tendons, ligaments, fascia), and poor posture/habits, results in a mechanical creep, or elongation of tissue beyond it’s intrinsic extensibility. In other words, many of the muscles that are stabilizers are stretched out and unable to adequately perform their job. Consequently, synergistic muscles are called upon (synergistic dominance- the neuromuscular phenomenon that occurs when inappropriate muscles take over the function of a weak or inhibited prime mover) and one develops faulty/inefficient movement patterns and eventually a cycle of chronic pain.
By the time most people are seen by their chiro or PT for pain, rather than trace the pain back to the “core” source, the symptomatic areas are addressed- over and over again.
Treat the cause not the symptom
In order to do this, an understanding of the core and how to engage these muscles is essential.
Functional anatomy of the core
The core can be functionally divided into 3 systems:
- Local stabilization
- Global stabilization
The local system muscles attach directly to vertebrae These are type I (endurance) muscles that are responsible for intervertebral stability between spinal segments. They also help with postural control and proprioception. Examples include: transverse abdominus, internal oblique, multifidus, pelvic floor muscles and diaphragm.
The global system muscles attach from the pelvis to the spine. These muscles transfer loads between the upper and lower extremities, providing stability between the pelvis and the spine. Examples include: quadratus lumborum, psoas, external oblique, rectus abdominus, gluteus medius (abductors) and adductors.
The movement system muscles attach from the spine or pelvis to the extremities and are responsible for concentric force production and eccentric deceleration during dynamic activities. Examples include: latissimus dorsi, hip flexors, hamstrings and quadriceps.
All three systems need to work synergistically and interdependently, in order to enhance stability and neuromuscular control.
Core training is often the key to eliminating chronic musculoskeletal pain. This does not mean that therapy (chiro,acupuncture, PT) is not important, but that therapy should be directed towards correcting the imbalance, not just addressing the symptoms.
Lets take the aforementioned example of the desk job worker who has low back pain. Typically, the hip flexors will be shortened (over active) and hip extensors lengthened (under active) with the outer back muscles (erector spinae) and hamstrings synergistically dominant. The erector spinae and hamstrings will feel tight as they attempt to provide stability. If a therapist stretches these muscles, the area will become more unstable and the muscles with likely tighten even more. ideally, the hip flexors (often opposite to the pain) should be lengthened, the local stabilizers should be strengthened, the hip extensors strengthened and the erector spinae and hamstring muscles (movement system) strengthened. In that order.
Training your core should start locally and move to the global and movement systems. Because the fiber type varies between the core muscles, the acute variables (e.g. sets, reps and tempo) needs to be considered when designing a program.
|Core system||Example of exercise||Sete/reps||*Tempo|
|Global & Movement||Back extensions
Ball bridge/curl combo
*The tempo describes the speed of the three different aspects of the contraction:
An efficient core ensures optimum length-tension relationships between opposing muscles (agonists and antagonists), optimum joint function and optimum movement patterns. In this state, the body will have optimum neuromuscular efficiency, which means less pain and better performance if you are an athlete.
Clark, M and Lucett, S. NASM Essentials of Sports Performance Training. Baltimore: LWW; 2010.
For more information on the core and a comprehensive library of exercises, visit my colleague Dr. Brent Brookbush, DPT: http://brentbrookbush.com/