Shoulder Special Test: Jerk Test

The Jerk Test is a special physical test used to assess the integrity of the shoulder joint. It involves having the patient hold their arm straight out to the side, and then quickly and surreptitiously pushing their arm down in a jerking motion. The test is applied to see how the patient responds to the external force and if there is any pain or instability in the joint. This can help identify various shoulder pathologies and can be used to help in the diagnosis and treatment of

Transcript

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This is Brent of the Brookbush Institute, and
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...blank
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in this video we're doing the jerk test.
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A special or orthopedic test for the
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shoulder, that helps us indicate a
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posterior inferior labral lesion. I'm
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going to have my friend Melissa come out,
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she's going to help me demonstrate. Now
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this is kind of tricky, we have to
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combine some actions that are not so
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easy to combine; which is stabilization
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of the scapula, we have to compress the
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humeral head into the glenoid fossa, and
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then we're going to simultaneously
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horizontally adduct the humerus. So
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here's what that looks like. We're going
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to take this hand the hand closest to
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the patient and we're going to put it
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right over the top of the scapula, and
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then our palm down over the back of the
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scapula. We're going to take our other
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hand using our lumbrical grip, that
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little crab or lobster grip, we're going
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to put that right over the elbow. Now
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we're going to start at 90 degrees of
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abduction, and roughly 90 degrees of
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shoulder internal rotation here, and I'm
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now going to press her humerus into her
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glenoid fossa. So my force will always be
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directed in line with the humerus itself,
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an axial load so to speak, and so we're
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going to push in this way, and then
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here's where it gets tricky. Maintaining
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that load I'm going to horizontally adduct
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the humerus, while asking my
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patient does that replicate your
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symptoms? Yeah. that's what you were
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complaining about. Where do you feel that? In
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the back of her shoulder. Alright so a
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positive Jerk test is the onset of pain
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in the back of the shoulder, with or
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without clicking. Of course clicking you
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can either hear or feel as you're going
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through the test. The most important
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thing is it does it replicate your
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patient symptoms. I'll show you guys a couple of
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other views here. Let me have you move
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this way Melissa. I just want you guys to clearly see
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the mechanics of this. Notice hand, top
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and then bracing the back of your
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scapula. I also have good control over
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her torso here. I'm then going to use
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this grip
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over her elbow, and then notice i get my
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elbows up nice and high so that my forearms
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match my directions of force pretty good.
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This is going to make it a lot easier on
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me, and then all i have to do is take a
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step and I can take her into a
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horizontal adduction, while maintaining
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that force in line with the humerus,
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compressing the humeral head, and I'm
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going to ask her is that the symptoms
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you were talking about? Where do you feel
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that? In the back of your shoulder, all
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right positive Jerk test. Alright go
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ahead and flip all the way around .One
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last view of my mechanics here. So this
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hand over the top stabilizing the back
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of the scapula. This hand over the top of
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her elbow, bracing her humerus, I've got
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good control here, I'm going to get my
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elbows up nice and high. I'm just going
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to take a step as I continued to
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compress her humeral head into her
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glenoid fossa, and of course all the
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while I'm asking does that match the
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symptoms you were talking about, is that
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what you were complaining about, where
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did you feel that. Alright, thank you Melissa.
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Now if I'm doing the Jerk test that's
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just one clue towards an assessment or
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diagnosis of what may be contributing to
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my patients complaints, I'm going to do
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other tests to confirm this assessment
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or diagnosism chances are if I've done
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the Jerk test I'm also going to do the
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Kim's test, because that's my other
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posterior inferior labral lesion test.
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Chances are I've already done my SLAP
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lesion tests. Things like the O'Briens
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active compression test and and maybe
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even Speeds, but I want to make sure that
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as I'm putting this together, I'm putting
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all my clues together, I have some
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negatives to ensure that it's not that
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diagnosis, it's not like a SLAP tear.
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Maybe I've done my impingement tests, my
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rotator cuff tests, and I know if those
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are negative but these are positive I'm
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really really on the right track. Now
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chances are you're going to get a mixed
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bag, and you're also going to have to
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match it up with a subjective evaluation. Now
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why is this all important, with our
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diagnostic testing you have to keep in
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mind is this patient going to get better
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with conservative treatment, i.e manual
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therapy and exercise. Or should I refer
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out to a physician, because there's a
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chance that we need some imaging maybe
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to make a better decision. Or is there a
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chance that surgical intervention is
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actually going to be the better solution
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for this patient right. You don't
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necessarily have to make that decision,
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if you are leaning towards a significant
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labral lesion that could need surgical
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intervention, personally I would go ahead
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and refer up to a physician, try to get
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some imaging, maybe talk with that
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physician and may be jointly we decide
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whether we should try conservative
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treatment at all, or we should skip
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straight to surgical intervention. I hope
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you guys enjoyed this video, give this
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test a try, it's a little tricky. I would
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practice it before using it in the
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clinic. If you have any questions leave a
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comment below.