Shoulder External Rotator Manual Muscle Testing (MMT) for an Active Population

Shoulder external rotator manual muscle testing (MMT) is a simple, efficient way to assess the strength of the shoulder external rotators in an active population. MMT tests the integrity of these muscles, aiding in our understanding of the functional status of the shoulder complex. Through assessing shoulder external rotation while the shoulder is in an internally rotated and adducted position, MMT evaluates the degree of external rotation strength, helps to identify any imbalances, and can help guide exercise selection

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 to do
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shoulder external rotator manual muscle
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testing for an active population. So,
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since we're going to go ahead and test a
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more active population, we're going to
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get rid of that Kendall scale of the one
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through five of the pluses and minuses and
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replace it with a simpler scale of
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strong, weak, with compensation, or with
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pain. But, we're going to pay a little
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closer attention to the details, because
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we know in that more active population, who
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is putting a little bit more stress on
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their musculoskeletal system, it often
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doesn't take a very large change in
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muscle activity, length, or we'll say joint
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alignment to start showing signs of pain
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and dysfunction. 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 these tests. Now, the
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first test we're going to use for the
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infraspinatus and teres minor, which we
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know have a propensity to get long and
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underactive, is the very traditional
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Kendall style test. It is prone, facing
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away, with their humorous supported by a table, and you
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guys can use a little towel under their
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humorous so that they they keep in good
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alignment throughout their shoulder.
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Since their chest tissue
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will lift them up a little bit, we want
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them in neutral position. Now, in this
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position, I have a lot of control over her
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shoulder girdle, so I can help stabilize
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it. Or, I can put it back into good
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position and just have her hold that. I
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can also palpate her infraspinatus, just
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under the spine of her scapula, or I can
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use my thumb to palpate her teres
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minor. Now, the first thing I'm going to
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do with this test is I'm actually going
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to check her range of
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motion. We can see Melissa actually
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has pretty close to optimal range at 90 or
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95 degrees of external rotation. If I
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have her do the same thing actively- now
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go ahead and do that for me- you guys will
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start to notice that she actually doesn't
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have the same range of motion actively.
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That's something I want to take note of.
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She has good passive range of motion, but
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her active range of motion is lacking.
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Now, if I have her go ahead and do that
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again and then I add some external
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resistance,
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what we notice with Melissa is she
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has a weak spot through here.
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and then she catches about here, at about
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75 to 80 degrees of external
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rotation. Now, if you're asking me, I'm
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actually going to make a note of that.
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That's a week test to me. Although, she
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may test a five in this position, if she
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doesn't have optimal strength all the
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way to 90 degrees, the question I start
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asking myself are will she keep that 90
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degrees of external rotation. If she's
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not stable and strong in a range of
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motion, there is a chance that she could
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lose that range of motion. So note: weak
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maybe week last 15 degrees and whatever you
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guys want to add as far as detail, but
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this would be a weak test to me. I'm
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going to go ahead and have Melissa sit
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up. Now, the test I use more commonly is
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not the traditional Kendall test, but
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it's the one I see a lot of people use
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in clinic, because it's
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convenient and has some advantages. It's
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not quite as strict as that test, but if
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I have Melissa just sit up here, put both
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her arms out, and I'm going to go ahead and make
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sure she's in a slightly flexed position,
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so maybe elbows lined up with the
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anterior side of a rib cage here. Once
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she's lined up this way, I have posterior
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delt a little bit inhibited, I'm making
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sure I get as much infraspinatus and
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teres minor as I can, and I can go ahead
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and push both arms at once. The
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advantage to pushing both arms at once
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is I can compare her two sides. With all
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manual muscle testing, there's a little
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bit of practice that you guys need to do.
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You have to start comparing
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individuals. It takes a little bit of
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time to kind of determine what is strong
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versus what is weak. I can't just tell
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you guys on camera that a strong result
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would give you X percentage, or X pounds,
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or she should be able to hold, because I
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can tell you right now that Melissa's
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infraspinatus and teres minor are not as
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strong as my pecs. Right? Those are much
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smaller muscles. But, I don't have to
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necessarily be able to rate her
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infraspinatus and teres minor versus my
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pecs if I can compare sides, especially
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she's coming to see somebody like me to
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correct some shoulder pain on
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her right side. I can do that test and
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immediately compare her left side to the
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right side, and now I have presumably a good
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side and a symptomatic side to compare
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to. The other thing that this position is
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really nice for is I can easily address
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or see compensation. Remember, that's that
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test result with compensation that we
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talk about a lot when it comes to
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using these tests for helping us
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determine postural dysfunction and
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intervention. If I come behind her, which
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isn't how I would do this test,
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but just so you guys can see on camera,
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if I push her into internal rotation,
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you can see her start to abduct at the
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shoulder and her elbows are actually
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starting to flare out a little bit.
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Her infraspinatus and teres minor
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definitely don't do abduction, so she's
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starting to try to use her overactive
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synergists, which in the case
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of the external rotators is posterior
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delt and supraspinatus, to try to
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abduct her shoulders to resist me rather
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than do pure external rotation. That's
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with compensation. If I know her
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compensation's abduction, maybe I'm
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thinking in the back of my head already that
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maybe one of the interventions I
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want to give her is supraspinatus
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release, or posterior deltoid release
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along with her external rotator
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activation. Now, I do want to show you
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guys one more view from the side. I would
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make sure Melissa's sitting up nice and
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tall so that I don't have her starting
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in a compensated position. I'm once again
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going to line her arms up so that her
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elbows are at her anterior rib cage, just
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to try to inhibit her posterior delt a
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little bit. We don't
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want that taking over from the get-go.
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And then, all I'm going to do is use my
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pecs to go ahead and push in and see if
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she can maintain that perfect posture.
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Melissa, as we could tell from the other test, does have, in my
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opinion, fairly weak external rotators.
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From this view, they're even and
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unless I'm cueing her to do so, she
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actually doesn't compensate. So, maybe in
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Melissa's case, since she doesn't
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compensate, I could get away with not
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doing supraspinatus release, not doing
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posterior delt release, which is two less
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releases I have to do. Maybe I don't
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have to do any posterior capsule
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stretching, which is one less stretch I
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have to do. But, I am going to go ahead
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and do some external rotator isolated
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activation and integration to try to get
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her shoulders a little stronger. I hope
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you guys enjoyed this video. I hope you
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guys enjoyed seeing my take on the
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external rotators, or infraspinatus and
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teres minor manual muscle test for an
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active population.