ABOUT REAL TIME ULTRASOUND

• Overview
• Background information
• What is ultrasound imaging?
• Scope of practice issues

BACKGROUND INFORMATION

Core Stability - What is it?

Core Stability is a term that has gained significant popularity in the rehabilitation and fitness fields in the past few years. Consequently its definition has become somewhat distorted from its original meaning.

The concept of Core Stability arose from research done at the University of Queensland in Australia in response to determining the type of exercise that was most important to prescribe to patients with low back pain. In its purest definition it refers to the ability to produce an isolated contraction of the deep postural muscles of the trunk. This contraction is important in the creation of adequate stiffness (stability) within the spinal column (vertebrae and discs) and pelvis, facilitating transfer of load. If an individual lacks the ability to contract the deep postural muscles undue stress is placed upon the vertebral column, pelvis and the joints of the lower extremities (hips, knees and ankles), when performing exercises that utilize the more superficial power muscles, (running, cycling pilates etc.).

Core Stability training involves the development of a skill to perform an isolated co-contraction of the deep postural muscles in the trunk, (this includes the deepest layers of your abdominal, and back muscles as well as the pelvic floor muscles). This skill is one that is not a birth right, and that is often lost with injury or, when these muscles undergo trauma for example with abdominal surgery or pregnancy. This skill is based on the fact that in normal individuals these deep postural muscles (the core) contract prior to trunk or limb movement to stabilize the spinal column and pelvis before the load of the movement is experienced. This anticipatory control suggests the existence of separate control mechanisms for the deep postural muscles (the core) vs. the more superficial trunk musculature. Core Stability training is about learning and training the specific control mechanism for the deep postural muscles.

Activation of the deep postural muscles (the Core) is not something that happens just because you sit on an exercise ball, uneven surface, tighten your tummy or think about directing movement from your centre of gravity. In fact if you have an inefficient co-contraction of your core muscles these activities may actually serve to over load your spine, pelvis or leg joints and cause injury.

However more accurate assessment can be performed with the aid of technical devices such as ultrasound imaging. Ultrasound imaging (just as is used to visualize a baby or your internal organs) allows for visualization of the various layers of the abdomen and back muscles while they are actually contracting, thereby demonstrating the ability or lack of ability to perform an isolated contraction of these muscles. This technology has been used by researchers in this area of study for some time and is now more readily available to the public.

If you have had a recent or chronic back injury, have under gone abdominal surgery, given birth in the past or would just like to avoid future injury you may benefit from an assessment of your Core Stability.

Current Trends In The Treatment of Low Back Pain & Pelvic Pain
- What is the Rationale for Prescribing Exercise for Individuals with Low Back Pain?

The current push towards evidence-based practice has encouraged all health care professionals to re-evaluate their management of low back pain (LBP) patients. From a rehabilitation point of view traditional exercise approaches have focused on strength, endurance and functional capacity training. Although these general programs are appropriate in the late stages of rehabilitation for increasing general muscular support of the spine and hold value for the deconditioned patient, recent research suggests that they do not address the physical impairments in the neuromuscular system associated with the onset, persistence and reoccurrence of low back pain, ^{1, 2}.

Recent evidence with regard to muscle dysfunction in patients with LBP has identified motor control impairments in the deep muscles of the trunk². From a neuromuscular point of view the muscles of the trunk can be divided into a global system or outer unit, and a local system or inner unit³. The global system consists of the larger, torque producing muscles that are superficial and important for controlling spinal orientation and balancing external loads. The muscles of the local system are deep, lie close to the vertebrae and are capable of increasing spinal segmental stiffness¹. The local system consists of the transversus abdominis, deep lumbar multifidi, pelvic floor and diaphragm. Evidence exists that suggests these inner unit muscles normally contract in anticipation of movement (before the global system) to augment the stability of the vertebral column and pelvis^{2, 4}. Further evidence shows this anticipatory function is lost in patients with low back pain and that it is not restored with the resolution of pain². It is reasoned that these impairments need to be specifically addressed before a more general exercise programs can be prescribed for patients.

A different and specific type of exercise termed segmental stabilization training has been developed that directly addresses these motor control impairments identified in the neuromuscular system1. Segmental stabilization training is aimed at protecting and supporting the spinal segments from re-injury by re-establishing and enhancing muscle control to compensate for any loss of segmental stiffness caused by injury or degenerative change². Segmental stabilization training is a specific therapeutic exercise program aimed at reversing the loss in the motor control of the local muscle system and to restore the normal synergy between the local and global systems¹.

The initial and pivotal focus is on retraining the co-contraction of the transversus abdominis and lumbar multifidi. During this retraining process, these local muscles are activated cognitively, and as independently as possible from the global muscles¹. Facilitation of the deep muscle motor patterning with relative independence from the global muscle activity requires a high level of clinical skill and training is significantly augmented with the aid of technical devices such as ultrasound imaging (so the patient/therapist can view the contraction of the deep muscles) and surface electromyography (which can monitor unwanted activity of the superficial global system). Once the motor control of the local system is restored then training is aimed on the integration of the local and global systems². Initial clinical trials point to the effectiveness of this approach in patients with both acute and chronic low back pain in terms of reducing the neuromuscular impairments and in control of pain ^{1, 5, 6,7}.

References;

Lumbar Dysfunction