A new analysis of existing studies indicates that extracorporeal shockwave therapy (ESWT) could offer relief for people experiencing frozen shoulder, a condition characterized by inflammation and thickening of the shoulder joint's connective tissue, leading to pain and limited mobility.

The research, conducted by scientists at Central South University in China, synthesized data from 189 studies involving almost 13,000 adults with frozen shoulder, with an average age of 54. The study compared various treatments against a placebo, focusing on pain levels, function, range of motion, and any reported side effects.

ESWT, a treatment commonly used for conditions like heel pain and tennis elbow, involves a clinician using a handheld probe to direct sound waves to the affected joint capsule and surrounding scar tissue. This process is thought to stimulate blood flow and healing compounds. Typically, a session lasts three to 15 minutes, and a course consists of three to six sessions spaced about a week apart. Without treatment, frozen shoulder can take up to three years to resolve on its own.

According to the findings, ESWT reduced short-term pain compared to usual care. The therapy may also improve short-term shoulder function and movement, although the researchers note these benefits are less certain.

Another treatment found to potentially ease short-term pain is manipulation under anesthesia, a procedure where a clinician stretches and moves the joint capsule while the patient is asleep. This method was found to be effective both when combined with a steroid injection and when performed alone.

Frozen shoulder generally progresses through three stages: 'freezing,' where pain is prominent and stiffness begins; 'frozen,' where pain subsides but stiffness is at its peak; and 'thawing,' where movement gradually returns. While most cases improve over time, up to 15 percent of patients may experience permanent limitations in arm movement.

Experts emphasize that gentle, consistent movement of the shoulder is crucial for managing the condition, as immobility can exacerbate tightening of the joint capsule. The analysis noted that evidence for long-term outcomes beyond three months and comparative safety data for many treatments remains less certain, with adverse events inconsistently reported.