Extracorporeal shockwave therapy, a treatment utilizing a pulsating probe to deliver sound waves to damaged tissue, may significantly reduce pain for individuals with frozen shoulder, according to a comprehensive analysis of studies.
Frozen shoulder, a condition characterized by inflammation and thickening of the shoulder joint's connective tissue, leads to deep, aching pain and restricted mobility that can persist for months or years. It affects approximately 5% of the population, with higher prevalence among women over 40 and individuals with diabetes.
Researchers from Central South University in China analyzed 189 studies involving nearly 13,000 adults who had frozen shoulder. The analysis compared various treatments against a placebo, assessing pain, function, range of motion, and side effects. The findings indicated that shockwave therapy reduced short-term pain compared to usual care.
The therapy involves a clinician using a handheld probe to direct sound pulses through the skin to the tight joint capsule and surrounding scar tissue. This process is believed to stimulate blood flow and healing compounds. Each session typically lasts between three to 15 minutes, with patients usually undergoing three to six sessions spaced about a week apart.
While shockwave therapy is commonly used for conditions like heel pain, tennis elbow, and shoulder tendonitis, it is not routinely funded by the NHS in the UK, leading many patients to pay privately, with costs ranging from £50 to £150 per session.
The research also suggests that shockwave therapy might improve short-term shoulder function and movement, though the researchers note these benefits are less certain. Manipulation under anesthesia, a procedure where a clinician stretches the joint capsule while the patient is asleep, was also found to be effective in easing short-term pain, both when combined with a steroid injection and when performed alone.
"Evidence for most other treatments, outcomes beyond three months, and comparative safety is substantially less certain because adverse events were incompletely and inconsistently reported," the researchers stated in their findings.
Separate research indicates that correcting a vitamin D deficiency could help reduce inflammation and pain associated with frozen shoulder, although supplements are generally beneficial only when a deficiency exists.
Frozen shoulder typically progresses through three stages: ‘freezing’ (pain is primary, stiffness increases), ‘frozen’ (pain eases, stiffness peaks), and ‘thawing’ (movement gradually returns, pain may persist). Without intervention, frozen shoulders can take up to three years to heal naturally, and up to 15% of patients may experience a permanent limitation in arm mobility.
Experts emphasize the importance of gentle, regular movement to manage the condition, as immobility can further tighten the shoulder capsule.