Mirror Therapy comes in many flavours. ;-)
You can use it for a variety of different symptoms, injuries and conditions.
Normally you would use a mirror that is perpendicular to your body.
But for external rotation that just doesn't work very well.
As soon as the arm starts to move too far outwards effectiveness decreases.
This also happens with the rubber hand illusion:
if the hands are more than 60cm apart it is very hard to evoke the illusion.
Somehow the brains processing changes and it doesn't integrate the rubber hand any longer.
So for a lot of problems concerning the shoulder mirror therapy is of limited use.
This video shows you how I use this type of therapy to increase range of motion - especially external rotation.
The patient in this clip had a motorcycle accident a year ago.
After rehabilitation and a follow-up neurological exam there still was no measurable EMG activity in his deltoid and biceps muscles.
He had surgery about 4 weeks ago where they removed scar tissue to free up the nerve to help it regenerate.
When asked to externally rotate the arm his initial reaction was "I don't know what to do", i.e. he had lost even the ability to mentally perform the movement.
This is one of the - let's call it side effects of immobilisation:
it's not that the joint, the muscle can't physically do the movement - but the brain has forgotten how to do it.
This is called learned non-use and is a big problem for example in stroke patients.
So the focus of the first treatment session was to show him what external rotation looks like.
That's why he has to be able to see both shoulders in the mirror.
He moves the unaffected one and can see how it looks.
As an additional visual aid I drew lines on his scapula so that he can better see them moving towards his spine.
In order for him to be able to focus on external rotation the weight of the arm is carried by the sling.
This setup is difficult to use at home - who has all that stuff laying around? - but it works great in the clinic.