This is Brent of the Brook Bush Institute, and in this video we're going to go over the
straight leg raise test. I'm going to have my friend a Yvette come out, she's going to
help me demonstrate. Now the straight leg raise test is a neurodynamic test for
the sciatic nerve and dorsal nerve structures, and what we're going to do is
lengthen this nerve and see if we can bring on neural symptoms or concordant
symptoms, so the patient's complaint, and when we talk about neural
symptoms usually we're talking about things like tingling and numbness,
and that pins and needles, paresthesia or that that searing pain. If any of you
have ever bumped your funny bone like you know that type of pain is
very different than muscular pain, so keep that in mind as we do this test. The
test itself is fairly simple, we're just literally going to raise a straight leg.
The two things you want to watch out for is we have to keep the knee
in extension and you want to leave the ankle alone in the initial test, and what
do I mean by leave the ankle alone, I mean leave it in neutral because any
movement of the ankle can change the tension in the sciatic nerve, all right
we'll get to that in a second. So if I go ahead and bring up her leg, what I'm
looking for is either the onset of tension with some of those neurological
symptoms or neurogenic symptoms I should say, so like I said paresthesia,
numbness, tingling or it starts bringing on her concordant sign down the leg, or
in her back. So I could go ahead and go Yvette does this bring on
any of your symptoms? No we're okay, still okay cool. We see Yvette does not have
flexibility issues, lucky her my hamstrings would have taken over by now;
and that's something to think about is keep in mind that we're kind of
pulling people up to what would be the end of hamstring extensibility in the
normal individual, so a little discomfort in the back of the knee or stretching
across the back of the leg those are very normal things and not a positive
test. A positive test would be like you get somebody up to here, they start
having like the shooting pain down the back of their leg, they start having
pain in their lumbar spine they start talking about that complaint
that they came in with that was related to that lumbar spine pain in the buttock
and sciatica, right that's what we're looking for. Now if you weren't sure, like
let's say you have this patient you get them to 45-degrees they're complaining
because they like to complain, they're not being very clear on whether it's
like hamstring tightness or whether it's more nerve involvement, well go ahead and
try the other leg. If you try the other leg and you get them to the same
position, they're still complaining about the same pain in the back of their leg
and it really doesn't sound like nerve involvement, you might just have somebody
who has hamstring tightness in both sides. Now the other thing that we could
do is we could start trying to sensitize this by adding tension to the nerve
itself and seeing if that provokes more symptoms. The first thing we could do to
increase tension in the dorsal nerve structures is I could do this test get
my position of where I know I'm running into tension, and then go okay
back off a little bit, let me have you tuck your chin to your chest, all right
and then if I go back up and she's complaining about her concordant
symptoms and that made it worse well I know her hamstrings don't attach
to her neck that would be very strange hamstrings. But we do know that
this is going to lengthen her spinal cord and increase tension in her
sciatic nerve. That's starting to get me thinking okay maybe this is a nerve
issue, so head up makes symptoms worse, potentially nerve. You could go to
the opposite way too, so you could go a flexion of the neck, go ahead
and come up see where that lets you go, and then that's let's say that's where
her symptoms are and then I back off a little bit, have her put her head down
and if all of a sudden I get a lot farther before I get symptoms again that
could be a sign of nerve stuff. Now some other stuff that is going to start
complicating this, before we complicate this any further though I want you
to master the test that I just laid out for you,
that is the straight leg test. That is the majority of what you're going to
need with most individuals, is just the ability to identify concordance signs on
the low-back, or back of the leg or neurogenic symptoms, so that you
understand whether there is nerve involvement in this person's pathology
or not. What I'm about to talk to you about is now getting a little bit
more specific with our diagnosis. So there is something called the 'Well
Leg Raise' sign, if I raise her opposite leg and that causes pain in her cited
back pain, so let's say she had right-sided low back pain I lifted her
left leg and that caused more right-sided low-back pain that is a big sign of
like a herniated nucleus pulposus. So that's like a big HMP sign.
So if you get symptoms increased in the low back with the opposite leg
raise we're thinking in the direction of HMP. Now let's say we go back to this
nerve root thing with a positive straight leg raise test but now I want
to get fancy, and I might get fancy for one of two reasons: either I have some
sort of responsibility regarding the diagnosis of what level this
radiculopathy is or what level we might have an H&P
rubbing on a nerve, so now I want to sensitize this test, try to determine
what nerve is involved at the lower portion of the leg to help me with that.
Or another reason to get fancy is I kind of dig these neurodynamic techniques,
I'm thinking one of these neurodynamic techniques might help, and if you
don't know what I'm talking about please look up Butler or Shacklock these
are great professionals with these techniques to help floss and stretch
nerves, especially in individuals who are have some sort of neurodynamic
pathology. I'll show you what we're going to do here
and I think you will catch on. So if I leave the ankle alone and just pull up
like this, chances are most of the tension is going through the sciatic and
tibial branch of the sciatic nerve. Now if I want to sensitize the tibial nerve
further I could add dorsiflexion, all right granted chances are I would
probably do that by doing this, and keeping this hand here. If I want to
sensitize even farther with the tibial nerve I could dorsiflex and evert.
So now I'm going to dorsiflex and evert and bring up. So now I have several
ways of sensitizing the sciatic and tibial nerve, remember I still have the
neck flexion thing, I now have dorsiflexion and dorsiflexion with
eversion. If I wanted to go sural nerve alright so now this is a different
segment, I would go dorsiflexion with inversion and pull up, right so if this
brings on concordant symptoms or this makes but the concordance symptoms much
much worse now I'm thinking sural nerve. Peroneal
nerve is kind of a weird one where we go plantar flexion and inversion,
sorry I change my hand position there, and come up this way. So again you
have tibial nerve is dorsiflexion and eversion, sural nerve is dorsiflexion and
inversion, peroneal nerve is plantar flexion and inversion, and again the
reason I said you might do those is either to help try to differentiate what
segments your involvement is at the lumbar spine, or you like those neuro-
dynamic techniques, or I guess we could add one further thing maybe you wanted
to experiment with releasing the muscles and tracts involved with the nerve that
you found to be most involved with this person's pathology. So I guess
we could throw on some fancy release techniques stuff there too. Now like I
said that got way way way more complicated real fast.
The original straight leg raise test you are looking for concordant symptoms
in the low back or back of the leg, just like this.
I'm grabbing ankle here, I'm grabbing just above the knee to keep knee extension
I'm not messing with any of this, I'm just all about Yvette's
symptoms and whether this is going to bring on neurogenic symptoms or whether I can
pull her leg all the way up to a point where I get hamstring involvement, giving
me a good indication that her sciatic nerve is not involved. I can compare legs
and should compare legs, if when I'm comparing legs the opposite leg brings
all the low-back signs, our low-back concordant symptoms that's the well leg
raise sign and that is a probably a good sign that we have some sort of disc
issue; and then of course last set, or I should say let me back up one, you also have
the chin thing to help sensitize this test. So does that make her
symptoms worse if she puts it down, go ahead and put your head down, I'm
sorry back on it there you go, just goes to show you patient
communication, so you have her head down on the table and that gives me a little
bit more range that gives me an idea that we have some nerve stuff. Then
of course last, if you want to get into the differentiation of which branch
of the sciatic nerve in the lower leg; we got tibial nerve is
dorsiflexion and eversion, sural nerve is dorsiflexion and inversion, peroneal
nerve is plantar flexion and inversion. I'll be quite honest with you I
often have to look these up because I tend to stick to that straight leg raise
sign for a really long period of time, and then when I occasionally get that
person who I can get into this stuff with I usually have to go back to my
notes a little bit, and there's nothing wrong with that just keep those
notes handy so that if you do want to get into some of the fancier stuff or
you do have a reason to think that you can help by differentiating what segment
you're at you have those notes handy. If you
have any questions please leave them in the comments section below, I'd be more than
happy to answer.