Core strength is the number one therapy to reduce low back pain and prevent injuries in sport. Low back pain is a prevalent disorder in modern society, with 80% of the population suffering from this condition at least once in their lifetime. This condition is increasingly seen in patients due to the economic development of society and changing work environment. The causes of low back pain are complex and multifactorial. One major cause of low back pain is typically weakness along with decreased motor control of the core muscles.
The core is an anatomical bridge between our hips and shoulders. The core muscles, which are the primary active stabilizers of the spine, can be divided into two groups according to their functions and attributes.
The first group is the deep core muscles, which act to locally stabilize the spine. These include the transversus abdominis, lumbar multifidus, diaphragm and pelvic floor muscles. The transversus abdominis attaches the ribs to the pelvis, while the lumbar multifidus is directly attached to each lumbar vertebral segment. The transversus abdominis and lumbar multifidus activate a co-contraction mechanism to provide spinal segmental stability and precise motor control.
The second group, known as global stabilizing muscles, are more superficial and include the rectus abdominis, internal and external obliques, erector spinae, quadratus lumborum, and hip muscles. These muscles enable additional spinal control by producing high torque to counteract external forces that impact the body. When both groups of core muscles function normally, they can maintain segmental spinal stability, protect the spine, and reduce stress to the lumbar vertebrae and intervertebral discs. Furthermore, increased core stability helps transfer the full force and power of movement from the lower extremities to the upper extremities and vice-versa.
In the large majority of sport-specific movements, such as kicking, throwing and swinging a bat, power is generated in the hips and then transferred through the core to the upper extremities. Likewise, the ability to maintain strong trunk positions during deceleration of momentum and reorientation of the body to run in a new direction on the field are critical for change-of-direction. A weak core will diminish the transfer of power and limit athletic performance.
A sound core exercise program will strengthen spinal muscles, enhance lumbar stability and result in a better foundation for force production in the extremities. Restoring function of weakened muscles in low back pain patients will augment the ability to support and control the spine and pelvis, thereby alleviating mechanical irritation and pain in the low back region.
Additionally, multifaceted injury prevention programs including core stabilization exercises are effective in reducing lower extremity injury rates. Evidence shows core instability training may reduce anterior cruciate ligament (ACL) injuries. Many muscles related to the knee joint originate in the lumbopelvic region and thus the core is an important contributor to knee and ankle stability.
A literature review examined the effects of core strengthening programs which included trunk balance, stabilization, segmental stabilization and motor control, as well as full body resistance training to strengthen the trunk and lower limb muscles. Pre- and post-evaluations were performed to determine the effectiveness of the exercise interventions among the control and experimental groups in the studies. The results showed reduced pain in the core strengthening group according to the Visual Analog Scale and McGill pain questionnaire. The experimental group also had significant improvements in muscle thickness on ultrasound following intervention.
There are a number of ways to build strength and challenge the core. Isolated exercises, such as the standard plank and side plank, can increase muscle activation and improve spinal stability. Dynamic or instability exercises are used to promote postural imbalance and require a greater stabilizing effort of the core muscles. Examples of instability exercises are bird dogs, side plank with rotation and bear crawl.
Article written by Dr. Jessica Khani, PT, DPT, CSCS
The information provided is not medical advice and is not intended to be used in place of seeking advice from a professional.
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