I have read a few claims that Microcurrent Therapy is effective to treat tendinitis, as illustrated below.
What is Microcurrent Therapy?:
Each tissue type in your body has its own signature electrical frequency, which may be disrupted by injury or disease. Microcurrent therapy simply restores normal frequencies within the cells, resulting in remarkable improvements in pain, inflammation and function.
What Conditions Is Microcurrent Therapy Good For?
[...]
Tendon and ligament pain
PainMaster Microcurrent-Therapy Patch:
Helps increase blood flow and reduce inflammation
The Wikipedia page on Microcurrent electrical neuromuscular stimulators contains a succinct section on effectivity but it lacks references:
A study by a neuroretinologist in the late 1980s suggested that microcurrent stimulation of acupuncture points for the eye had positive effects in slowing and even stopping progression of macular degeneration[citation needed]. This treatment is used to treat both the Wet and Dry forms of AMD. This study was based on Ngok Cheng's research on the increased amounts of ATP levels in living tissue after being stimulated with microcurrent.[7] Several similar studies are currently under way and other studies have shown there are benefits (with specific microcurrent polarities and frequencies) on the healing of tendon and bone.
Is Microcurrent Therapy effective to treat tendinitis?