Acromioclavicular (AC) Joint Resisted Extension Test

The Acromioclavicular (AC) Joint Resisted Extension Test is a clinical orthopedic test used to assess the integrity of the Acromioclavicular ligaments which connect the distal clavicle to the acromion. This test is usually used when evaluating shoulder injuries such as shoulder impingement syndrome or a rotator cuff tear. During the test, the patient is asked to extend the arm away from the body and is then resisted by downward pressure against

Transcript

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This is Brent of the Brookbush Institute,
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...blank
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and in this video we're going over the special
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orthopedic test for the
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acromioclavicular joint, the resisted
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extension test. I'm going to have my
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friend Melissa come out, she's going to
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help me demonstrate. Now I think you guys
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are going to see a small nomenclature or
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wording error in this test as we start
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to set it up. This test goes, I'm going to
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use one hand to brace her torso, so I'm
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going to do that fingers over the top of
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the scapula and then palm over the back
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of the scapula thing that you've seen in
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a lot of the videos we've done on
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special tests, and I'm going to use this
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hand to resist her arm once I put it in
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90 degrees of flexion, 90 degrees of
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horizontal adduction, 90 degrees of
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internal rotation, and 90 degrees of the
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elbow flexion. So this very squared up
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posture right, we got a nice little right
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angle here at her elbow, and then her
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elbow is both in line and level with
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her shoulder. Now here's where the
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nomenclature issue comes in, this is
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called the resisted extension test but
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what you're actually resisting is
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horizontal abduction. So if Melissa
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pushes her elbow out towards me that's
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the test right, this would be extension
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extensions a sagittal plane joint
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action, this is horizontal abduction or
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horizontal extension. So I'm not really
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sure what happened with the naming of
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this test, but make a note guys so that
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if you are using this test you don't get
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confused on where you should be
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resisting. So once again brace, resist,
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I'm just going to have a push out, ask
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her that telltale question, is that the
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symptoms you were talking about? That
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would be a positive if that replicates
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your symptoms, specifically if it
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replicates her symptoms at her AC joint
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that would be a positive. So i'm going to
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show you guys what that looks like at
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another angle, let me have you face that
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way. So again bring her up to elbow in
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line and level with your shoulder, and
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then 90 degrees of elbow flexion here,
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brace your torso, go ahead and resist,
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does that replicate your symptoms? Ok i'm
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going to show you guys the other way,
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good, you guys can see that brace hand. So
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I'm going to do this, this, so now I have
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control of her torso, I can push Melissa
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around a little bit, I've just got to be
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careful because she'll push back. Alright
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and then I'm going to use this hand to
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resist, you guys can see how I'm set up
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nice and strong, you guys can see I'm in
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a staggered stance. Go ahead and push out
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Melissa, good does that replicate your
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symptoms? All right I'm going to turn you
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guys back around one more time to see
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this view just to go over one other
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tendency I have. If Melissa had for
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example had a negative test result right,
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so I had to go ahead and push out, she's
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super strong and I go does that
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replicate your symptoms and she goes no,
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and then what I'll do is palpate the AC
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joint, so no pain there huh, and she says
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no after palpating the AC joint, a lot of
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times I'll sneak in that palpation
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because it is a very sensitive but not
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very specific test, which means if i get
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negatives for both her resisted
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extension test, and no pain when i'm
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pushing down on her AC joint I have a
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really good chance that it's not AC
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joint pathology. So tests that have high
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sensitivity of low specificity can be
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useful as screens if you get a negative
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test result. If I got a positive test
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result and I would probably want to add
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another couple other AC joint testing,
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we're going to talk about the AC joint
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cluster in another video. Thank You
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Melissa. As with all of these special
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orthopedic test guys we never use just
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one test, hopefully you guys now
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understand the technique behind this
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test, and you have one more tool in your
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arsenal as you start bringing tests
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together to build your case towards
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accurate diagnosis, hypothesis generation,
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and optimal intervention. I look forward
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to seeing your questions in the comments