The Science Behind Shock Wave Therapy and Back Pain -

Outline:

Introduction
What is shock wave therapy?
Defining the two most-used types
Common origins of back pain
How shock wave provides relief from back pain
Research backing this effect
Conclusion

Medical professionals heavily follow and research solutions to chronic back pain, as approximately 80% of people in the entire population experience back pain at least once during their lives¹. A multitude of therapy options have been presented with the hope or promise of providing a better quality of life for chronic back pain patients, but today we are going to take a look at shock wave therapy (also known as pressure wave therapy and focused shockwave therapy) and its impact on back pain conditions.

The goal is a generalized consensus: Does shock wave therapy improve the quality of life for those suffering from chronic back pain?

What is shock wave therapy?

Shock wave therapy uses acoustic waves to transmit high peak pressure waves to promote and accelerate the body’s own natural healing for subacute and chronic conditions. This technology triggers a variety of biological responses including:

Remodel fibrotic tissue, release trigger points
Reverse chronic inflammation
Increase nitric oxide (NO)
Activate stem cells and human growth factors (New cell growth)
Increase blood flow, microcirculation
Stimulate tissue remodeling, neovascularization
Modulates pain fibers causing an analgesic effect

Defining the Two Most Common Forms of Shock Wave

Shock wave therapy is most commonly seen in two forms: focused shock wave therapy and acoustic radial pressure wave therapy. Fundamentally, these two types of shock waves share the same purpose – trigger the body’s own biological regenerative effects. This offers to promote faster, more effective healing. How do they differ though?

Acoustic radial pressure waves move through the body along a radius. They reach areas with a depth of up to 5-6 cm, depending on the pressure and applicator tip used. The energy decreases as the depth increases. As a result, radial pressure waves are particularly beneficial for treatment of superficial zones. The variety of transmitter tip options enable both localized and generalized treatments for a range of myofascial conditions. Muscle (kinetic) chains are treated functionally in a linear direction. Radial pressure wave therapy stimulates tissue layers to break up adhesions and trigger points. In addition, the shifting of the layers of tissue causes a myofascial release – a vital prerequisite for fascial treatment.

On the other hand, the therapeutic capacity of focused shock waves reaches a depth of up to 12.5 cm. Therefore, they are primarily used for the treatment of deeper conditions and areas such as non-specific back pain, greater trochanter pain syndrome, insertional hamstring tendinopathy, and piriformis syndrome, Focused technology allows for precise, pinpoint treatment (for example of trigger points or tendon insertion) because the energy is delivered exactly where it is needed.

Causes of Back Pain

Back pain is the second most common source of pain in the general population². It affects every age group, every gender, and every ethnicity. The lower back is the prevalent location of pain reported, specifically the lower five vertebrae (L1-L5) in the lumbar region and the sacro-iliac joints. Pain is often described as constant, dull aches but can also include sudden sharp pain.

There are two types of back pain:

Acute pain is described as short-term back pain lasting a few days to a few weeks. Most back pain reported is acute. It usually resolves itself with self-care and there is no residual loss of mobility. In some cases a few months are needed for the symptoms to fully dissipate.

Chronic back pain is defined as pain that is ongoing for 12 weeks or longer. Often this type of pain continues even after an injury or underlying condition of acute back pain has been treated. About 20% of people affected by acute back pain develop chronic back pain with persistent symptoms at one year².

Most acute back pain is mechanical in nature, meaning that there is a disruption in the way the components of the back (the spine, muscle, intervertebral discs, and nerves) fit together and move. Some examples of mechanical causes of low back pain include:

Injuries

Sprains (overstretched or torn ligaments), strains (tears in tendons or muscle), and spasms (sudden contraction of a muscle or group of muscles)
Traumatic Injury such as from playing sports, car accidents, or a fall that can injure tendons, ligaments, or muscle causing the pain, as well as compress the spine and cause discs to rupture or herniation.

Degenerative Problems

Intervertebral disc degeneration occurs when the rubbery discs wear down as a normal process of aging and they lose their ability to cushion.
Spondylosis is the general degeneration of the spine associated with normal wear and tear that occurs in the joints, discs, and bones of the spine as people get older.
Arthritis and other inflammatory diseases of the spine, including osteoarthritis and rheumatoid arthritis as well as ankylosing spondylitis, an inflammation of the vertebrae.

Nerve and Spinal Cord Problems

Spinal nerve compression, inflammation and/or injury
Sciatica (also called radiculopathy) is caused by pressure on the sciatic nerve that travels through the buttocks and extends down the back of the leg.
Spinal stenosis, the narrowing of the spinal column that puts pressure on the spinal cord and nerves
Spondylolisthesis happens when a vertebra of the lower spine slips out of place, pinching the nerves exiting the spinal column
Herniated or ruptured discs can occur when the intervertebral discs become compressed and bulge outward
Osteoporosis (a progressive decrease in bone density and strength that can lead to painful fractures of the vertebrae)

Congenital

Skeletal irregularities such as scoliosis (a curvature of the spine), lordosis (an abnormally exaggerated arch in the lower back), kyphosis (excessive outward arch of the spine), and other congenital anomalies of the spine.

Spina bifida or the incomplete development of the spinal cord and/or its protective covering. This often causes problems involving malformation of vertebrae and abnormal sensations and even paralysis.

Non-Spine Sources

Kidney stones can cause sharp pain in the lower back, usually on one side
Endometriosis (the buildup of uterine tissue in places outside the uterus)
Fibromyalgia (a chronic pain syndrome involving widespread muscle pain and fatigue)
Tumors that press on or destroy the bony spine or spinal cord and nerves or outside the spine elsewhere in the back
Pregnancy (back symptoms usually go away after giving birth

How Does Shock Wave Therapy Affect Back Pain?

Chronic back pain that triggers discomfort and inconvenience in daily life tends not to respond to conservative therapy in many cases, which has prompted a search for other therapeutic methods. Shock wave therapy is a frequently sought out option, but why?

Shock wave therapy is known for producing several biological effects that maximize reducing back pain. The decrease in substance P and other pain provoking chemicals, stimulation of inflammatory reduction, increase in the blood flow rate and revascularization stimulates and reactivates the process of healing of the tendons, surrounding tissues, and bones. These effects are associated with an increase in mobility and an overall decrease in pain.

Research

Study 1⁵

This study examines the effects of extracorporeal shockwave therapy (ESWT) for patients with chronic back pain and their dynamic balance ability. Two groups were used: extracorporeal shock wave therapy group (ESWTG) and a conservative physical therapy group (CPTG).

An exercise program that included Williams’ exercises and McKenzie’s exercises was performed by both groups. The program was implemented twice a week for six weeks. The visual analog scale (VAS) was used to measure the chronic low back pain of the patients. Their dynamic balance ability was measured with BioRescue.

[Results] The within-group comparison of the VAS of the ESWTG and the CPTG showed significant improvements after the intervention. In the VAS comparison between the groups after the treatment, the ESWTG showed a significantly larger improvement. In the within-group comparison of dynamic balance ability, the ESWTG showed significant improvements.

Study 2³

This study observes the effects of extracorporeal shock wave therapy (ESWT) on chronic back pain and the quality of life of those with back pain. 200 patients with chronic back pain were divided into an observation group and a control group using a random number table. Patients in the observation group underwent ESWT, while those in the control group received laser therapy. The degree of pain was evaluated using the visual analogue scale (VAS) and compared between the two groups before and after treatment. The quality of life of patients, including physical health, bodily pain, social function, general health, mental health and emotional health was scored and compared after treatment. The patients were followed up for 1 year after treatment.

Results: The VAS score dropped markedly in both groups compared with that before treatment, and the observation group had an evidently lower VAS score and a significantly higher effective rate than the control group (94.00% vs. 64.00%, P<0.05). After treatment, the quality of life score in the observation group was higher than that in the control group (P<0.05), and the observation group had a lower incidence rate of complications than the control group (P<0.05).

Study 3¹

This study examines the effects of extracorporeal shock wave therapy on pain, disability, and depression of chronic low back pain patients. Chronic low back pain patients were divided into an extracorporeal shock wave therapy group (ESWTG) and a conservative physical therapy group (CPTG).

The ESWTG received extracorporeal shock wave therapy and the CPTG received general conservative physical therapy two times per week for six weeks. Pain was measured using a visual analog scale (VAS), the degree of disability of the patients was assessed using the Oswestry Disability Index (ODI), and their degree of depression was measured using the Beck depression index (BDI).

In intra-group comparisons, ESWTG and CPTG showed significant decreases in VAS, ODI, and BDI scores. Intergroup comparisons revealed that these decreases in VAS, ODI, and BDI scores were significantly larger in ESWTG than in CPTG.

[Conclusion] Extracorporeal shock wave therapy is an effective intervention for the treatment of pain, disability, and depression in chronic low back pain patients.

Conclusion

Research supports the use of shock wave therapy for back pain and it is used widely in the world of physical therapy and rehabilitation for this exact reason. By promoting the body’s own healing processes, shock wave therapy stimulates a faster and more effective treatment method than conservate therapy on its own.

For more information on the research backing ESWT for back pain reduction or to learn more about shock wave therapy – email info@kinasmedical.com

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