Shoulder and knee pain are among the most frequent reasons people seek medical care, affecting millions of individuals around the globe. Whether caused by sports injuries, everyday wear and tear, or repetitive stress, these conditions can severely impact one’s quality of life.
Written by
Angel Rigueras
Pain Management Specialist
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Written by
Angel Rigueras
Pain Management Specialist
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Recently, extracorporeal shockwave therapy (ESWT) has gained attention as a non-invasive, innovative alternative to surgery and long-term medication, offering hope for those who have struggled with persistent musculoskeletal pain.
ESWT utilizes precisely controlled high-energy sound waves that travel through the skin to reach deeper tissues. Unlike the dramatic shockwaves of an explosion, these targeted waves are designed to gently stimulate the body’s natural healing processes. By promoting increased blood flow, reducing inflammation, and triggering cellular repair, ESWT works to address the root causes of pain rather than merely alleviating symptoms.
Originally documented in 1980 by Dr. Christian Chaussy for breaking up kidney stones in lithotripsy procedures, the use of shockwave therapy has evolved dramatically over the decades. Its early success in urology paved the way for research into orthopedic applications, where scientists discovered that shockwaves could enhance fracture healing and effectively treat overuse injuries affecting tendons and fascia. Today, as evidence continues to mount in support of its benefits, ESWT is becoming an invaluable tool in the arsenal of sports medicine and musculoskeletal health care.
In this article, we will explore what extracorporeal shockwave therapy is, how it works, and why it represents a promising treatment option for shoulder and knee pain.
Extracorporeal shockwave therapy (ESWT) utilizes high-energy acoustic waves that create pressures up to 1000 times greater than those produced in standard ultrasound imaging. There are two main types of ESWT used in clinical settings: focused shockwave therapy and radial shockwave therapy (often called radial pressure waves). Although the exact mechanisms remain under investigation, researchers believe that these shockwaves elicit both mechanical and cellular responses that contribute to tissue healing and pain modulation.
At its core, ESWT is based on the principle of mechanotransduction—the process by which mechanical forces are converted into biochemical signals that promote tissue repair. Here’s how the process works:
When the shockwaves penetrate the skin and underlying tissues, they produce a range of effects, including absorption, reflection, refraction, and energy transmission. This energy can mechanically disrupt structures such as calcific deposits in cases like calcific tendonitis and even modify scar tissue to improve function.
Unlike larger, damaging injuries, ESWT induces controlled “micro-trauma” at the cellular level. This small-scale injury is enough to activate the body’s natural repair mechanisms without causing significant tissue damage. In response, affected cells release adenosine triphosphate (ATP), growth factors, and cytokines—key players in the regeneration process. These substances help repair and rebuild damaged tissue, thereby reducing chronic pain.
Another benefit of the shockwaves is the stimulation of new blood vessel formation, a process known as neovascularization. Enhanced circulation increases the delivery of oxygen and essential nutrients to the injured site, accelerating the healing process.
On a molecular level, the shockwaves affect the activity of ion channels on cell membranes and trigger the release of nitric oxide. This response not only contributes to pain relief but also promotes anti-inflammatory and angiogenic (new blood vessel formation) effects. Additionally, ESWT has been shown to increase collagen synthesis via the upregulation of factors like TGF-β1 and IGF-1, as well as interleukins (IL-6 and IL-8) and metalloproteinases (MMP-2 and MMP-9). These changes support the remodeling and strengthening of injured tissues.
ESWT may also reduce pain by directly stimulating nociceptive C-fibers. This stimulation can increase the release of pain-inhibitory substances (for instance, substance P) and may desensitize the nerve receptors through a mechanism similar to the gate-control theory of pain, offering rapid pain relief that is sometimes noticeable immediately after treatment.
Because ESWT does not involve surgical incisions or injections, it is generally associated with minimal discomfort, no scars, and a low risk of infection. It is performed on the outside (extracorporeal means “outside the body”) and uses focused shockwaves. For many patients, especially those who wish to avoid surgery, this non-invasive approach is a major benefit.
Unlike surgical procedures, ESWT does not require lengthy hospital stays or extended periods of rehabilitation. Patients can often return to their normal activities soon after a session, and many report improvements with only minor adjustments to their daily routines.
Medications—particularly long-term use of painkillers or anti-inflammatory drugs—can have significant side effects, including gastrointestinal issues, kidney problems, and dependency concerns. ESWT provides a drug-free option that minimizes these risks. Although some patients may experience temporary soreness or swelling at the treatment site, these side effects are generally mild and short-lived.
The shockwaves help improve blood flow, reduce inflammation, and promote tissue regeneration. Rather than simply masking pain, ESWT addresses the underlying issues by stimulating the body’s natural repair mechanisms. This can lead to more lasting improvements compared to treatments that only offer temporary pain relief.
While commonly used for kidney stones, ESWT is also effective for tendon problems, calcific deposit conditions, and joint pain.
Shoulder pain can arise from various conditions, including rotator cuff tendonitis, calcific tendonitis, and adhesive capsulitis (frozen shoulder). These conditions often limit mobility and reduce quality of life. Traditional treatments, such as corticosteroid injections, nonsteroidal anti-inflammatory drugs (NSAIDs), or even surgery, come with risks and side effects. ESWT provides an alternative that can help many patients without the need for invasive procedures.
Conditions Treated in the Shoulder:
This condition involves the inflammation or tearing of the rotator cuff tendons. Pain is usually most noticeable during overhead activities. ESWT can help by reducing inflammation and stimulating tendon repair, thus improving shoulder function and reducing pain.
Calcific tendonitis involves the deposition of calcium in the tendons. The condition is often painful and can limit shoulder movement. The shockwaves in ESWT help break up these calcific deposits, enabling the body to absorb them over time. Research has shown that patients with calcific tendonitis benefit from ESWT, experiencing significant pain relief and improved mobility after treatment.
Although not always the first treatment recommended, ESWT may be an option for patients with frozen shoulder who haven’t responded to other conservative treatments. By promoting tissue repair and reducing inflammatory mediators, ESWT can help restore range of motion and decrease stiffness.
Clinical studies have consistently shown that ESWT can lead to significant improvements in shoulder function and pain reduction. For example, one study noted marked improvements in shoulder pain in patients with chronic tendinopathy after receiving shockwave therapy. Another report emphasized that the biological changes induced by ESWT—such as improved blood flow and tissue regeneration—are key to its success in treating various shoulder conditions.
Knee pain is another common condition that can drastically affect mobility and quality of life. It often results from osteoarthritis, patellar tendinopathy (jumper’s knee), or other injuries that affect the joint’s soft tissues. ESWT has been gaining attention as a treatment option for knee pain due to its non-invasive nature and its ability to stimulate healing.
Conditions Treated in the Knee:
Knee osteoarthritis is a joint disease characterized by the possible breakdown of cartilage, reshaping of a joint that may lead to pain, stiffness, and swelling. While ESWT does not reverse osteoarthritis, it may help reduce inflammation and pain and improve joint function. Studies have indicated that shockwave therapy can stimulate cartilage repair to some extent and reduce inflammatory markers in osteoarthritic knees.
This condition typically affects athletes who participate in sports that involve a lot of jumping or sudden changes in direction. The repetitive strain leads to micro-tears in the tendon, causing chronic pain and dysfunction. ESWT helps by stimulating the repair of the tendon tissue and reducing pain, allowing patients to gradually return to full activity.
In addition to osteoarthritis and tendinopathy, ESWT can be useful in managing various soft tissue injuries around the knee. These might include issues with the quadriceps tendon or ligament sprains, where the treatment’s anti-inflammatory and regenerative properties can reduce pain and promote recovery.
Scientific studies have underscored the benefits of ESWT in managing knee pain. One meta-analysis reviewed several clinical trials and concluded that ESWT significantly reduced pain scores and improved function in patients with knee osteoarthritis and tendinopathy. Additionally, older research into the cellular responses triggered by shockwave therapy provides insights into the biological mechanisms that underlie the clinical improvements seen in these patients.
During an ESWT session for shoulder or knee pain, the patient typically sits or lies in a comfortable position while the therapist uses a hand-held device. A gel is applied to the shoulder or knee affected area to enhance the transmission of shockwaves. The device is then placed over the painful area, and the machine sends controlled shockwaves into the tissues. The procedure is usually well tolerated, although some patients describe the sensation as a series of rapid taps or a mild pressure. Sessions typically last 15 to 20 minutes, and a course of treatment may include several sessions spread out over a few weeks. Most patients undergo multiple sessions to achieve optimal results, with the number of sessions dependent on the severity and duration of the pain.
Immediately After Treatment ESWT session, patients may notice some mild soreness around the treated area. This is a normal response and is believed to be part of the healing process. Many patients report a reduction in pain and improved mobility within a few days of treatment, even though full benefits may take several weeks to become evident.
Post-Treatment Care, Healthcare providers usually recommend specific post-treatment guidelines to maximize the benefits of ESWT, including:
-Resting the treated area for a short period
-Avoiding high-impact activities until the area has had time to recover
– Following up with physical therapy or exercises to strengthen the muscles around the affected joint
– Monitoring for side effects, such as excessive pain or swelling, and reporting them if they occur
By adhering to these recommendations, patients can help ensure the best possible outcome from the therapy.
While ESWT has shown promise for many patients, it is not a one-size-fits-all solution. Ideal candidates typically include:
Before starting ESWT, patients will undergo a thorough evaluation by their healthcare provider to ensure the treatment is appropriate for their specific condition. In some cases, additional imaging tests such as MRI or ultrasound may be recommended to pinpoint the source of pain and guide the therapy.
If you or a loved one is experiencing shoulder or knee pain, consider exploring ESWT as part of your treatment plan.
Its non-invasive nature, coupled with the promising outcomes reported in both scientific literature and patient experiences, makes it an appealing option. Remember to consult a qualified healthcare provider who can evaluate your condition and determine if ESWT is the right choice for you.
With advancements in technology and a better understanding of how shockwaves promote healing, the future looks bright for those battling the chronic pain that can limit daily life.
By embracing innovative treatments like extracorporeal shockwave therapy, we are taking important steps toward more effective, less invasive care. Whether you are an athlete, a busy professional, or simply someone who wants to enjoy life without the constant burden of pain, ESWT offers a glimpse into the future of pain management and tissue healing.
For more detailed information and guidance on this exciting therapy, consider reaching out to our specialists in sports medicine at University Orthopedic Care Clinics.
Don’t hesitate to consult us at (866) 962-1744 or conveniently request an appointment online. We offer specialized, advanced treatment provided by board-certified orthopedic surgeons, utilizing the latest orthopedic treatment technologies.
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