Friday, November 4th, 2022
The shoulder is the most complicated joint in the human body. It’s also one of the most difficult aspects of recovery for hemiplegic stroke survivors.
A common issue with hemiplegic stroke is shoulder subluxation, defined as a partial or incomplete dislocation that usually stems from changes in the mechanical integrity of the joint (muscles, tendons ligaments).
There are several treatment protocols for treating subluxation.
Electrical stimulation is one of the more common treatments, but many therapists are doing it wrong.
The well-known traditional electrode placement for shoulder subluxation, for decades, has been the supraspinatus muscle and posterior deltoid.
The original rationale was based on research articles by Basmajian et al. I’m dating myself, but this was before Atari was popular.
Back then, the consensus was that given the vertical vectors for the supraspinatus and posterior deltoid, it made clinical sense to use these two muscles for surface stimulation.
Despite limited evidence, most clinicians never questioned if these placement sites were actually the best for lifting the humerus up into the joint (proximal migration). Since it was considered “standard practice”, and well believed in the clinical community, many clinicians accept these electrode placements as gospel and continue this practice still today.
However, if one looks at cadaveric and percutaneous stimulation studies, one will quickly realize that we have it WRONG.
Over the past 10 to 15 years, studies have indicated that the supraspinatus is NOT one of the top two muscles to stimulate subluxation.
#1 The prevalence of supraspinatus asymptomatic tears is as high as 50% in the stroke population (similar to age adjusted group). Ouch, this means stimulating a torn tendon could make matters worse!
#2 Cadaveric and percutaneous stimulation studies have emerged showing that the supraspinatus is not a powerful proximal migrator, despite earlier theories.
To illustrate this point, the strongest proximal migrators are the middle and posterior deltoid (Chae et al).
Top 5 muscles for superior translation, lifting the humerus up (Halder et al.):
Supraspinatus was #6!
As clinicians, we are great at adapting and modifying to maximize outcomes, yet therapists continue to recommend supraspinatus as one of the key muscles for electrode placement.
Now is a good time to “close the gap” on traditional concepts and update our electrode placement guidelines for subluxation.
Check out a wireless electrical stimulation device which is ideal for shoulder subluxation.