Examination of Muscles

Transcript

• 00:10going to talk today about
• 00:13the examination of muscles.
• 00:15Now, weakness can be a very subjective
• 00:17term if we're talking about fatigue and
• 00:19the ability to do things, but in fact,
• 00:22weakness should be used very objectively.
• 00:25So weakness is the inability to
• 00:27take full resistance at the full
• 00:30kind of movement of muscle groups,
• 00:32and we test for weakness to both
• 00:35evaluate function and look for the
• 00:37presence of muscle or neurologic disease.
• 00:40The patterns of weakness we're looking for
• 00:43are with myopathies such as polymyositis,
• 00:46tomatomyositis, steroid myopathy,
• 00:48you will get symmetric proximal
• 00:51muscle weakness.
• 00:52So the shoulder muscles will be
• 00:55weaker than the wrist muscles.
• 00:58The hip muscles will be weaker than the
• 01:01ankle muscles in patients with a myopathy.
• 01:03In a peripheral neuropathy,
• 01:05you will have involvement of all the muscles
• 01:09from one particular peripheral nerve.
• 01:11So we see peripheral neuropathy
• 01:13in patients with diabetes,
• 01:15patients with vasculitis and with mechanical
• 01:17problems such as a carpal tunnel syndrome.
• 01:20So an example of a peripheral neuropathy
• 01:22is a femoral neuropathy often seen in
• 01:25patients with socalled diabetic amyotrophy.
• 01:28And they will have isolated weakness of
• 01:30the hip flexor and the knee extensor
• 01:32because those two muscle groups get
• 01:34their innovation from the femoral nerve.
• 01:37If we see a patient with foot drop and
• 01:40there's no involvement of the hip muscles,
• 01:42so there's a weakness of the ankle
• 01:44and foot and great toe dorsiflexor,
• 01:46but full strength of the hip muscles,
• 01:48that tells us that we're dealing with a
• 01:52perineal palsy for nerve root weakness.
• 01:54And this is where the exam can be very,
• 01:56very helpful.
• 01:57The conditions that give us nerve
• 02:00root weakness are disc herniation
• 02:02and the cervical and lumbar spine,
• 02:04a Caloquinos syndrome, cervical osteophytes.
• 02:07And it's the pattern of weakness
• 02:09that is very, very helpful.
• 02:11So if a patient has L4L5 and
• 02:15L5S1 lumbar disk disease,
• 02:17they're going to have weakness
• 02:18not only of the hip muscles,
• 02:20their hip abductors and their hip extensors,
• 02:22but concomitant weakness of
• 02:24their ankle and foot muscles,
• 02:26the ankle dorsal flexor and
• 02:28the great toe extensive.
• 02:29So that concomitant weakness tells us
• 02:32that we're dealing with a back problem.
• 02:35A child with the so-called herbs palsy
• 02:38will have C5C6 weakness and then
• 02:41you'll have weakness of the shoulder
• 02:43abductors and the elbow flexes.
• 02:45But the elbow extensors are fine.
• 02:50Cord lesions are due to conditions
• 02:52such as spinal cord injuries,
• 02:54tumors, developmental abnormalities,
• 02:56and here you'll have weakness
• 02:58at one level all the way down.
• 03:00You'll sometimes have skip areas,
• 03:02but generally speaking,
• 03:03if a patient has a spinal cord tumor,
• 03:05they're going to have weakness.
• 03:06If they have a weakness at at L2,
• 03:09all the muscle groups below L2 will be weak.
• 03:14The central nervous system lesions in
• 03:16the brain such as a stroke or a tumor,
• 03:19you'll see weakness in the distribution
• 03:21of the lesion and usually you'll
• 03:23have weakness of both the arm and
• 03:25the leg on one side of so-called
• 03:27hemiparesis when you have
• 03:29a central nervous system lesion.
• 03:32So the technique of the manual muscle
• 03:34exam is first of examine the muscles
• 03:37looking for wasting pseudohypertrophy,
• 03:39asymmetry of the muscle,
• 03:41mass fasciculations or involuntary
• 03:44movements such as chorea.
• 03:46Most importantly, you want to palpate
• 03:49the muscle looking for muscle tone.
• 03:52If there is fascidity,
• 03:53we're probably dealing with
• 03:55a lower motor neuron lesion.
• 03:57If there is spasticity, particularly
• 03:59so-called class knife spasticity,
• 04:01we're usually dealing with
• 04:03an upper motor neuron lesion.
• 04:05So the exam itself is an excellent
• 04:08method of ascertaining patterns
• 04:10of weakness and the presence of
• 04:13weakness and subtle peripheral
• 04:15nerve or nerve root weakness.
• 04:17And what I've tried to do is
• 04:20choose muscle groups which give
• 04:21me the most bang for the buck.
• 04:23So I'm going to look only at
• 04:25the shoulder abductors when I'm
• 04:27looking at shoulder muscles,
• 04:28because all the rest of the
• 04:30shoulder muscles are also C5C6 and
• 04:32then multiple peripheral nerves,
• 04:33so they don't add very much to my
• 04:36diagnostic human in the lower extremities.
• 04:38I'm going to look at all four
• 04:40groups of hip muscles because they
• 04:42each have different nerve root
• 04:44and peripheral nerve innervation.
• 04:46The hip abductors, adductors,
• 04:49flexors,
• 04:50and extensors all have different innervation.
• 04:54So technique for group muscle testing
• 04:56is first of all to fix the bone
• 04:59adjacent to the joint that you're testing.
• 05:02So if I'm looking for wrist extension,
• 05:06I want to fix the forearm because
• 05:08I don't want to recruit the elbow
• 05:11muscles and shoulder muscles in
• 05:12that particular maneuver.
• 05:14I want to position the patient
• 05:17in an anti gravity position.
• 05:19But most importantly I want to
• 05:23resist the person's maneuver and
• 05:26and activity as close as I can to
• 05:29the fulcrum of the joint itself.
• 05:32So if I resist shoulder abduction
• 05:34at the wrist,
• 05:35I'm taking the socalled lever arm
• 05:38advantage and becomes very subjective.
• 05:40If I resist shoulder abduction as
• 05:42close as I can to the shoulder,
• 05:44the patient has the lever arm
• 05:47advantage and it's a much more
• 05:49objective test of strength.
• 05:51Now fortunately,
• 05:52the British Medical Research
• 05:54Council has given us a very good
• 05:57system for grading muscle strength.
• 05:58Zero is no contracture.
• 06:001A Trace is contracture of the
• 06:02muscle but no movement.
• 06:04Two or poor is contraction with
• 06:06full range of motion but not
• 06:08with gravity involved.
• 06:09So you have to eliminate gravity to
• 06:12get a two or a poor for a three you do
• 06:15full range of motion against gravity.
• 06:185 is normal,
• 06:19can take full resistance,
• 06:21and four is between 3:00 and 5:00.
• 06:25So the technique I'm going to use
• 06:27today in muscle testing is to detect
• 06:29groups of muscles and I've selected them.
• 06:31I'm going to start with shoulder abduction.
• 06:33I'm then going to look at the flexors
• 06:35and extensors of the elbow and
• 06:37then I go look at wrist extension,
• 06:39finger abduction and thumb
• 06:40opponents in the hand and wrist.
• 06:42For the lower extremity.
• 06:44I'm going to again look
• 06:45at hip flexion extension,
• 06:47abduction and adduction.
• 06:48I'm going to look at knee
• 06:50extension and I'm going to look at
• 06:53ankle and great toe dorsiflexion,
• 06:55ankle E version and ankle plantar flexion
• 06:59with the patient seated facing me.
• 07:02I'm going to start with proximal muscles
• 07:04and I'll ask the patient to abduct
• 07:06or pick up his or her arm and I'm
• 07:09going to resist here and the patient
• 07:11should always be able to beat me.
• 07:13If I take the lever arm advantage
• 07:14and come out here,
• 07:15it becomes very subjective.
• 07:16So you always want to get close
• 07:19to the joint so that the patient
• 07:21has the lever arm advantage.
• 07:23Looking at shoulder abduction.
• 07:25Sometimes in the shoulder I'll be
• 07:28interested in what's called the
• 07:30serator seratus anterior muscle,
• 07:32and that's innervated by the long
• 07:34thoracic nerve and that fixes the scapula.
• 07:36So they ask the patient to hold
• 07:38their hand back like this,
• 07:39like they're going to stop traffic.
• 07:41I'll put my hand here and I'll push back.
• 07:43And if I push back and the
• 07:45scapula comes back this way,
• 07:47this weakness of the serratus
• 07:49anterior muscle indicating an
• 07:51injury to the long thoracic nerve.
• 07:54Now with the elbow,
• 07:55I want to check elbow flexion
• 07:57and elbow extension,
• 07:58so I'm going to hold the upper arm.
• 08:00I'm going to ask the patient
• 08:02to simply take their arm back,
• 08:03take their wrist,
• 08:04bring it back to their shoulder,
• 08:06and then I'll try to overcome the patient.
• 08:08So again, I'm pulling here,
• 08:09not up here,
• 08:10and the patient should be able to beat
• 08:13me if there's normal muscle strength.
• 08:15So that's elbow flexion.
• 08:17Elbow extension is very important
• 08:19because I use it all the time
• 08:21looking at cervical disc disease.
• 08:22So here I'm going to grab the upper
• 08:24arm and I'm going to ask the patient to
• 08:26simply straighten out his or her arm.
• 08:27So I'll demonstrate what I want them
• 08:29to do and then I'll simply resist them
• 08:31so they're straighten out your arm
• 08:32good and the patient should be able to,
• 08:34again, easily push me out.
• 08:36I don't want to do here because
• 08:38that becomes subjective.
• 08:39I want to do here and ask the patient
• 08:41to straighten their arm completely out.
• 08:43So I've done elbow flexion
• 08:45and elbow extension.
• 08:47Now looking at the hand muscles,
• 08:49I'm going to look at the brachial plexus,
• 08:50innovative muscles of the hand
• 08:52and I'm going to start with the
• 08:54radial nerve or wrist extensor.
• 08:56And again I want to hold the upper arm.
• 08:58So I'm not recruiting the
• 09:00elbow or shoulder muscles.
• 09:02I asked the patient to pull their
• 09:04hand back and I try to resist him.
• 09:06So this is radial nerve, it's C6C7.
• 09:09So patient with a radial nerve
• 09:11palsy is socalled saty, not saty.
• 09:14Night palsy will have isolated
• 09:15weakness of the radial nerve.
• 09:17Now the finger abductors or the muscles
• 09:20that simply spread the fingers part.
• 09:23OK,
• 09:24now the finger abductors are innervated
• 09:27by the ulnar nerve as well as C7C8T1.
• 09:31So if somebody has significant
• 09:34weakness of their ulnar nerve you're
• 09:37going to see some wasting here,
• 09:39so-called inter osceo wasting.
• 09:40And the test is simply to have the
• 09:43patient straight pull their fingers
• 09:44apart and you try to overcome them.
• 09:46Again, close here, not out here.
• 09:48Here. So this is finger abduction,
• 09:53C7C8T1, ulnar nerve.
• 09:54And the third muscle group I'm going to
• 09:57look at is the so-called opponent's polycus.
• 10:00And here I'll have the patient take their
• 10:02thumb and hold it to their little finger.
• 10:04Now I'm interested in these muscles here,
• 10:06not these muscles here,
• 10:07so I'm not going to do this.
• 10:09That's not a good way of
• 10:10testing the opponent's polycus.
• 10:11The way to test the opponent's
• 10:13polycus is have the person hold
• 10:15their thumb to their fifth finger
• 10:17and then pull at the base Here,
• 10:19And this is a very important one because
• 10:21this is the median nerve and patients
• 10:23with a carpal tunnel syndrome will
• 10:26get weakness of their median nerve and
• 10:28their their opponent's polycus muscle.
• 10:30So for the hands extension Abduction
• 10:34and opponent's polycus thumb
• 10:36to the little finger.
• 10:38So just to point out the anatomy here,
• 10:41we looked at shoulder abduction which
• 10:44is C5C6 and we looked at shoulder
• 10:47pushing the ceratus anterior muscle
• 10:49which is the long thoracic nerve.
• 10:52We also looked at elbow flexion which is
• 10:57C5C6 and elbow extension which is C7C8.
• 11:01And in the hands and wrists
• 11:03we looked at wrist extension,
• 11:05which is radial nerve C6C7.
• 11:09We looked at thumb opposition,
• 11:11the opponent's polycus muscle,
• 11:13and that's median nerve C6C7.
• 11:16And we looked at finger abduction,
• 11:18which is the ulnal nerve C8T1.
• 11:21So if you see a person that only
• 11:23has weakness of finger abduction has
• 11:27perfectly normal elbow muscle strength,
• 11:29you're probably dealing with
• 11:31an ulna neuropathy,
• 11:32very commonly seen in patients
• 11:34with diabetic neuropathy.
• 11:36If you see a patient with elbow extension
• 11:39weakness and finger abduction weakness,
• 11:42you're looking for C7C8
• 11:45cervical disc disease.
• 11:47So when I examine the hips,
• 11:48I'm going to violate one of my rules
• 11:50and that is for some of the maneuvers.
• 11:52I'm going to give the patient
• 11:54mechanical advantage,
• 11:55but do it distally and hopefully
• 11:56you can understand that.
• 11:58So for the hip muscles,
• 12:00we're particularly interested in
• 12:02nerve roots and peripheral nerves.
• 12:04So one way to remember the nerve
• 12:07root innervation of the hip muscles
• 12:09is a Doolittle iris step dance,
• 12:11and that is the hip flexors are L2L3.
• 12:16The hip adductors towards the
• 12:19midline are L3L4.
• 12:20They have abductors away from the midline
• 12:24are L4L5 and the hip extensors are L5,
• 12:28S 1.
• 12:28So you simply go
• 12:33to 334-4551 and you got the nerve roots
• 12:36testing the lower extremity muscles.
• 12:38The patient should be lying down.
• 12:40We're going to start with a hip
• 12:42and we're going to violate one of
• 12:43our rules about being close to
• 12:45the fulcrum for obvious reasons.
• 12:46So I'm going to start with a hip flexor,
• 12:48ask the patient to pick their
• 12:50leg up off the bed and I'll try
• 12:52to push it down and that's L2L3.
• 12:55I'll next look at the hip add
• 12:57doctors towards the midline,
• 12:59and here patients don't like
• 13:00it grabbing in their groin,
• 13:02so I'm going to look use the
• 13:04trying to pull the feet apart.
• 13:06So a normal person should
• 13:08be able to overcome me.
• 13:10Their legs are stronger than my arms,
• 13:12so if they can hold their feet
• 13:14together and I can't pull them apart,
• 13:16they've got pretty normal hip adductors.
• 13:18That's L3L4 for hip abduction.
• 13:23I'll bring the leg out here,
• 13:24ask the patient to hold the leg
• 13:26out there and I'll push back here.
• 13:28And that tests L4L5 for hip extension.
• 13:33What I'm going to do here is I'm going
• 13:35to overcome the gluteus maximus muscle.
• 13:37So I'm going to ask the patient
• 13:39to fix their leg on the bed and
• 13:41I will try to overcome that.
• 13:42So I ask the patient to fix the leg
• 13:44on the bed and I'll try to pick it up
• 13:46and I shouldn't be able to pick the leg up.
• 13:48And that's a pretty good way of testing the
• 13:51gluteus maximus muscle or the hip extensor.
• 13:55So for the knee,
• 13:56I'm going to look at knee extension.
• 13:58It's very simple.
• 13:59Bend the patient's leg.
• 14:01I'm going to ask them to straighten
• 14:03out their leg and they bend
• 14:05the leg and straighten it out.
• 14:08Again,
• 14:08I'm giving the patient the mechanical
• 14:11advantage this test the quadriceps and
• 14:13tests L4L 3L4 as a very simple maneuver.
• 14:17Then the patient's legs come down
• 14:19through that and we're going to
• 14:21look at the ankle and foot muscle.
• 14:23So we're going to start with the ankle
• 14:26dorsiflexor tibialis anterior muscle,
• 14:28that's L4L5 and it's a perineal nerve.
• 14:32So I ask the patient to pull their foot
• 14:34back and I try to overcome that both sides.
• 14:38Now the problem with this maneuver is the
• 14:41tibialis anterior muscles pretty strong,
• 14:43so I'm going to miss subtle weakness of L4L5.
• 14:46So the best way to pick up subtle weakness
• 14:49is to test the great toe extensor.
• 14:52So here I'll ask the patient to
• 14:54pull their great toe back and I
• 14:56will simply try to at the base of
• 14:57the toe see if I can overcome the
• 14:59patient's ability to hold it back
• 15:01and I shouldn't be able to,
• 15:03if I can,
• 15:04this weakness of the great toe extensor.
• 15:07So the last two muscle groups of the
• 15:09foot are what's called the ankle inverter.
• 15:11And here they have the patient pull
• 15:13their ankle out like this and I
• 15:15try to push it in like this.
• 15:17So the ankle inverters are L5,
• 15:19S 1, the superficial perineal nerve and
• 15:23the last group is the ankle plantar flexor.
• 15:26And here I'll ask the patient to
• 15:28push down their foot against me
• 15:31and that's the tibial nerve S1S2.
• 15:33So that's the completion of the
• 15:37lower extremity examination.
• 15:38So to review with you the anatomy of
• 15:41the lower extremity muscle groups,
• 15:43why we do this examination?
• 15:45The hip flexor is L2L3 femoral nerve,
• 15:50the hip adductor towards the
• 15:52midline is L3L4 obturated nerve.
• 15:55The hip abductor is L4L5 and that's the
• 15:59superior gluteal and the hip extensor
• 16:02is L5 S one and the inferior gluteal.
• 16:05Now we looked at the knee extensor
• 16:07which is the quadriceps which
• 16:10is the femoral nerve and L3L4.
• 16:12We didn't look at hip flexors
• 16:14because it's multiple muscles,
• 16:15multiple nerves and not very helpful.
• 16:18And then finally,
• 16:19they're very important ankle and foot
• 16:21muscles because of their concomitant
• 16:23innervation with the same nerve roots
• 16:25that innervate the hip muscles.
• 16:27So the ankle dorsiflexor is L4L5,
• 16:31deep perineal nerve, great Toeic sensors,
• 16:34L5 deep perineal nerve, ankle inverter,
• 16:39L5S1 superficial perineal nerve,
• 16:41and the ankle plantar flexor S1S2
• 16:45is the tibial nerve.
• 16:47Now let's look at,
• 16:48if we can some results of the
• 16:50manual muscle exam to see if that's
• 16:52that they can give us a clue on
• 16:54what's going on with the patient.
• 16:56So here's a patient that has weakness
• 16:58of all the muscle groups on one side
• 17:00arm and leg and that's consistent
• 17:02with a central nervous system lesion,
• 17:05a stroke or a brain tumor.
• 17:07This next patient has a weakness
• 17:09at one level all the way down,
• 17:11so from the hip muscles all the way
• 17:13down to the ankle muscles is weakness
• 17:15and that's consistent with a cord lesion,
• 17:18spinal cord injuries,
• 17:19A spinal cord tumor etcetera.
• 17:22This next patient has weak more weakness
• 17:25of symmetric proximal muscle weakness
• 17:28of both the upper and lower muscle groups.
• 17:32So the muscles get stronger as you get
• 17:35more distal and that's consistent with
• 17:39a myopathy or so-called polymyositis,
• 17:41the amount of myositis syndrome.
• 17:44This next group has very isolated
• 17:47weakness of the elbow extensor in
• 17:50the finger abductor and what is
• 17:53similar to those two muscle groups
• 17:56is the root innovation of C7C8T1.
• 17:58So if you see a patient with
• 18:01isolated weakness of elbow extension
• 18:02and finger abduction,
• 18:04think neck disease as the
• 18:06cause of that weakness.
• 18:08So the next patient is isolated weakness
• 18:11of the finger abductors bilaterally
• 18:13and this is classic for diabetic
• 18:16neuropathy and ulnar neuropathy.
• 18:20This next patient has isolated weakness of
• 18:23the hip flexor and the extensor on one side.
• 18:27So what is common to those two muscle groups
• 18:29is their innovation by the femoral nerve.
• 18:32So this is very typical
• 18:34for diabetic amyotrophy,
• 18:35A femoral neuropathy.
• 18:38And the final patient is a patient
• 18:41who has a weakness of both their
• 18:43hip and ankle and foot muscles.
• 18:46So the L4L5 and L5S1 innovative
• 18:48muscles of the hip,
• 18:50the abductor and the extensor
• 18:52and the L4L5 and L5 innovative
• 18:54muscles of the ankle and foot,
• 18:56the ankle and Dorsiflex of the great
• 18:58toe Dorsiflexor and the ankle inverter.
• 19:00So when you see that pattern of weakness,
• 19:03that's very consistent with back
• 19:06disease or lumbar disc disease.
• 19:09So I've demonstrated you today a very
• 19:11simple exam that takes very little time.
• 19:14You sit the patient down.
• 19:15You check their shoulder abductors,
• 19:17elbow flexors, elbow extensors,
• 19:19wrist extensor, finger abductor,
• 19:21and thumb opponents.
• 19:22You lie them down.
• 19:23You check the flexors, abductors,
• 19:25adductors, and extensives of the hips,
• 19:28the extensives of the knee and the ankle,
• 19:31and great toe dorsiflexes,
• 19:32inverters and plantar flexors.
• 19:34That's all you need to do.
• 19:35But what you do need to know
• 19:37is a bit of the anatomy,
• 19:39the nerve roots and peripheral nerves
• 19:42that innervate those structures
• 19:44so you can look at the pattern of
• 19:46weakness and that can lead you to your
• 19:48next step in trying to evaluate the
• 19:51cause of this patient's dysfunction.
• 19:53So you do need to learn a little anatomy,
• 19:55have one around you that will give you
• 19:57the nerve roots and peripheral nerves of
• 20:00these muscle groups we looked at today.
• 20:02Thank you.