Chapter 23: Upper Extremity Limb Pain Assessment

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Welcome back to The Deep Dive.

Today we're opening up a topic that I think everyone assumes is, you know, pretty straightforward until they're actually in the room with a patient.

We are talking about upper extremity limb pain.

The classic.

The classic.

The patient walks in, holds their arm, and says,

it hurts right here.

And you think, great, simple.

And that is exactly where the trap is.

Because it hurts right here could mean anything.

It could be a muscle strain from playing tennis.

Yeah.

A broken bone from a fall.

Right.

A pinched nerve coming from their neck.

Or, and this is the scary part, it could be their heart screaming for help.

Right.

It's a complete diagnostic minefield.

So we have a massive stack of material today, and we're focusing specifically on Chapter 23 from Advanced Health Assessment and Clinical Diagnosis in Primary Care.

A great chapter.

It really is.

And our mission is to do exactly what the title says, a deep dive.

We aren't just skimming the surface.

We're going to walk through the clinical framework presented in this text, step by step.

We want to take you from that initial doc my arm moment, all the way to, well, hopefully,

a definitive diagnosis.

And to do that, we have to appreciate the geography we're dealing with.

The upper extremity is incredibly crowded real estate.

I mean, think about your own arm for a second.

It's true.

In a very small space, you have long bones, small bones, you have complex hinge joints, ball and socket joints, muscles, tendons, ligaments,

a whole web of nerves, and a highway of blood vessels.

And they're all packed in so tight.

Exactly.

Yeah.

And because they're so packed, figuring out which specific neighbor in that neighborhood is causing all the noise.

That's the challenge.

Yeah.

Plus, like we mentioned, the arm is a master of disguise.

It loves to refer pain.

The problem might be in the cervical spine, your neck, but you feel it in your fingers, or the problem is in your chest, you feel it in your shoulder.

So before we even start pressing on arms and twisting wrists, the text lays out a roadmap, a way to organize the chaos in your head before you even touch the patient.

They suggested a mnemonic for assessing pain.

It's PQRST.

PQRST.

This is the absolute bread and butter of history taking.

If you are a student listening to this, tattoo this on your brain.

I mean, seriously, if you skip this, you are just guessing.

And in medicine, guessing is, well, it's dangerous.

Let's really unpack this letter by letter.

P is for provoke or alleviate.

Right.

So this is all about mechanics.

You're asking the patient, what were you doing when it started and then what makes it worse now?

Like specifically what?

Specifically.

Does lifting a coffee cup hurt?

Does reaching for the seatbelt hurt?

But also the other side of it, what makes it better?

Does holding it against your chest help?

Does ice help?

What have you tried that works?

It's the cause and effect.

It's pure cause and effect.

If they say it hurts when I lift my arm over my head, you're already narrowing it down.

You're thinking about the shoulder mechanics, specifically the rotator cuff or impingement.

Okay.

But I think it's a, it hurts constantly.

Even when I'm lying perfectly still, that's a very different signal, a much more concerning signal.

Which leads us to Q for quality.

And I feel like this is always the hardest one for patients to answer.

It is because pain is so subjective,

but you have to dig for the adjectives.

You don't want to put words in their mouth, but you need to know, is it burning?

Is it sharp?

A dull ache?

Is it

throbbing?

Shooting.

And these words, they actually correspond to specific tissues.

They really do.

Burning or shooting or electric.

That is almost always nerve pain.

That's a nerve screaming, aching or throbbing.

That's usually bone or deep muscle.

And then sharp or stabbing often points to a mechanical issue, you know, like a tear or a catch in the joint.

Okay.

So R is for radiation.

Yeah.

And this connects right back to that crowded neighborhood concept we were talking about.

Does the pain stay put?

If I poke it, is the pain right there under my finger?

Or does it travel?

Or does it travel?

If a patient says my neck hurts a little, but I have this shooting electric shock going down to my thumb, that's radiation.

That tells you the source is likely upstream, probably in the neck.

And the arm is just where the nerve is reporting the problem from.

S is severity.

The classic zero to 10 scale.

It's classic for a reason.

On a scale of zero to 10, with 10 being the worst pain you have ever felt in your life, where are you right now?

Right.

But the text makes a really important point here.

You have to establish a baseline for that person.

A five for one person might be a nine for someone else.

But tracking that number for that patient helps you understand if the condition is getting worse or if it's responding to treatment.

And finally T for timing.

This is the real detective work.

When did it start?

Was it sudden like a snap or was it gradual, insidious?

Is it constant or does it come and go?

And a huge one, a really huge one.

Is it worse at night?

We're definitely going to come back to worse at night later because that is a major red flag, isn't it?

It's a massive red flag.

Most

musculoskeletal things, you know, sprained and startled, they usually like rest.

If you lie down, they feel better.

Sure.

If the pain wakes you up at three in the morning, or if it ramps up when the sun goes down, you have to stop and think, okay, is this something else entirely?

So we have PQRST in our toolkit.

Now let's move to the initial diagnostic reasoning.

The text presents this as a fork in the road.

The patient is sitting there.

You've done your PQRST.

What is the absolute first decision you have to make?

The first decision is not what is the diagnosis.

That's not it.

The first decision is, is this patient safe?

Okay.

We need to determine, is this emergent?

Does this condition require immediate intervention to prevent disability or death?

That sounds pretty dramatic for a sore arm.

It sounds dramatic, but it's the reality of primary care.

You are the gatekeeper.

The text is very, very clear on this.

You aren't worried about tennis elbow in the first 30 seconds.

You're worried about, is this limb going to die?

Is this patient having a heart attack?

Is there a catastrophic infection brewing?

So let's dive into section one of our outline, analyzing the symptom, specifically the red flags.

These are the do not miss diagnoses.

The text lists a few.

The first one is acute compartment syndrome or ACS.

Let's break this down.

What is actually happening physically in ACS?

Okay.

So imagine your muscles are grouped into these bundles and these bundles are wrapped in a really tough casing called fascia.

Okay.

Fascia is fibrous.

It is not elastic.

It does not stretch like a balloon at all.

It's like wearing a pair of jeans that are three sizes too small.

That is the perfect analogy.

Exactly.

Now imagine you have an injury inside those jeans, a crush injury, a bad fracture, or even a severe burn.

You start bleeding or swelling inside that tight fascial compartment.

And the fluid has nowhere to go.

Nowhere.

So the pressure starts to rise and rise.

And because the fascia won't stretch, the pressure pushes inward.

It pushes inward on everything inside the muscles, the nerves, and the blood vessels.

And eventually the pressure inside the compartment actually exceeds your blood pressure.

The capillaries just collapse.

Wow.

Blood can't get in to feed the muscle.

Oxygen is cut off.

And muscle tissue without oxygen.

Dies.

And it dies fast.

That is why this is a surgical emergency.

The text highlights the key symptoms.

Severe pain.

But not just, ow, it hurts.

It's pain that's totally out of proportion to the injury.

If they have what looks like a small bruise, but they are screaming in agony, you have to think ACS.

And the text also mentions burning and numbness.

That's the nerves dying.

Right.

We often talk about the five P's in school pain,

pallor, paresthesia,

pulselessness, and paralysis.

But the text implicitly warns us,

do not wait for pulselessness.

Why not?

If the pulse is gone, it's often way too late.

The damage is done.

You need to catch it at the severe burning pain stage.

And the fix for this is?

Surgery.

A fasciotomy.

They literally slice the fascia open to let the muscle breathe.

This is an immediate referral.

No hesitation.

Okay.

That's red flag number one.

Let's talk about the neck.

Cervical spine injury.

This is usually trauma related.

And the text separates this by age, which is really helpful.

In adults, it's often falls or trauma to the head and neck.

You know, a car accident.

Okay.

In children and adolescents, you should think about sports.

Diving into a shallow pool.

Spear tackling in football.

Things like that.

And why is this an arm pain red flag?

Because the nerves that power the arm, they all come from the neck.

If you fracture a cervical vertebra or you rupture a disc, it can compress those nerve roots.

The patient might not complain about their neck as much as they complain about their arm being numb or weak or burning.

So if there's a mechanism of trauma, a fall, a tackle, and they have arm symptoms.

You assume the neck is broken until proven otherwise.

That's the rule.

You immobilize them.

You put a collar on.

You do not let them move their head.

And if they have neurologic signs,

numbness,

weakness, you transport them immediately.

Then there's the heart.

We touched on this, but let's be specific.

Myocardial ischemia.

Yeah.

This is the classic referred pain scenario.

The heart muscle is struggling for oxygen.

The nerves that supply the heart, they share a pathway in the spinal cord with the nerves from the arm, specifically the left arm, usually, but it could be both.

So the brain gets confused.

The brain gets completely confused.

It interprets the distress signal from the heart as pain in the arm.

The text says immediate referral.

No ambiguity there.

Absolutely.

If a patient comes in with arm pain, especially if it's vague, aching, or heavy, and they have risk factors, age, smoking, history of heart disease, or if they have associated symptoms like nausea, sweating, or chest pressure, you call 911.

You do not treat the arm.

You treat the heart.

Period.

The last red flag in this group is a bit slower moving, but just as dangerous.

Bone cancer or osteomyelitis?

This goes right back to our PQRST timing discussion.

The text describes this as unrelenting diffuse pain, and the key phrase, the one to remember, is often occurring at night.

Why is the nighttime so critical here?

What's happening?

Because mechanical pain usually sleeps.

If you have a rotator cuff tear, it might hurt if you roll onto it, but generally, if you aren't moving, it settles down.

Okay.

Tumors and infections, they don't care if you are moving.

They are biologically active.

They create treasure and inflammation from the inside out.

So if a patient tells you, I was fast asleep and my arm started throbbing so bad it woke me up, and they didn't roll on it,

you have to investigate for malignancy or infection.

Okay.

Deep breath.

We've cleared the red flags.

The patient is stable.

Now we can put on our detective hat and look at location.

The text has this great section that basically matches location to the problem.

Let's play a little game.

I'm ready.

I'm going to point to a spot on my body, and you tell me what the text says is the likely culprit.

First,

I am pointing to the very top of my shoulder, right on the peak.

Okay.

That suggests the AC joint, the acromioclavicular joint, or potentially arthritis in the main glenohumeral joint.

But usually, that point tenderness right on top is the AC joint.

Okay.

Now I'm grabbing the side of my arm, the deltoid muscle.

Ah, the classic trap.

You're grabbing the muscle so you think it's a muscle strain, right?

Well, ideally.

You're wrong.

The text notes that pain in the deltoid region is the most common referral pattern for the

a patient with a torn supraspinatus tendon, which is deep inside the shoulder, will almost always rub the side of their arm.

That's a trick.

That's a total trick.

Don't get fooled into treating the deltoid muscle when the problem is the tendon upstairs.

That is a great clinical pearl.

Okay.

What about the base of the thumb?

Right here.

If it's right at the base, near the wrist, especially if it hurts when you pinch your keys or open a jar,

that is classic arthritis of the first CMC joint.

Or, as we'll discuss later, a tendonitis like Dick Ravain's.

And lastly, what if I come in and say, doc, both my wrists hurt and both my elbows hurt?

Bilateral pain.

That changes everything.

It is highly, highly unlikely you injured both arms in the exact same way at the exact same time, unless you were in a major car wreck or something.

Bilateral pain screams systemic.

You'd be thinking rheumatoid arthritis, lupus, a flu -like illness.

Yeah.

It's inside the blood affecting everything symmetrically.

Okay.

Moving on to the how, the mechanism of injury.

The tech spends a good amount of time clarifying terms that patients, and honestly some providers, mix up.

Strain versus sprain.

This is Anatomy 101, but it really matters for diagnosis.

A strain with a T involves the muscle or a tendon.

Okay.

And remember, tendon connects muscle to bone, I tell students.

I have to do teaching.

Strain, tendon.

I like that.

Strain, tendon.

Strains are often from overuse or repetitive trauma.

Think tennis elbow.

Rotator cuff tendonitis.

It's the muscle unit getting overworked and inflamed.

And a sprain.

A sprain involves the ligament, and ligaments connect bone to bone.

They're like the seatbelts of the joint.

Sprains happen when you force a joint past its normal range of motion.

You roll your ankle, you jam your finger catching a ball, you stretch, or you tear that seatbelt.

So broadly speaking, strain is usually I did too much, and sprain is usually I moved funny.

That's a great way to put it.

Sprains almost always have a specific traumatic event.

I fell.

I tripped.

The ball hit my finger weird.

Speaking of falling, let's talk fractures.

The text outlines four specific fractures with very specific stories.

Let's build a profile for each one.

First up.

The Bennett Fracture.

Okay, so picture a young male.

Maybe he's agitated.

Maybe he plays rough sports.

He comes in clutching his hand.

The Bennett Fracture is an oblique fracture right at the base of the thumb.

The first metacarpal.

The mechanism, punching a wall, punching a helmet, punching a person.

The force goes right down the thumb and snaps the base.

Next one, the scaphoid fracture.

This is the one that scares everyone in primary care.

It should.

The mechanism is the foosh,

a fall on an outstretched hand.

You trip, you put your hand out to catch yourself, palm down.

The force jams the carpal bones together.

The scaphoid is this little peanut -shaped bone that bridges the two rows of wrist bones.

It takes the brunt of that impact and it can snap.

And why is it so scary?

I mean, a broken bone is a broken bone, right?

Not with the scaphoid.

The blood supply to this bone is terrible.

It's what we call retrograde.

It enters from the distal end, the top, and flows backwards.

So if you break it?

If you break the bone in the middle, the waist, you cut off the blood supply to the bottom half.

If you miss this diagnosis, the bone dies.

A vascular necrosis.

The wrist is ruined forever.

And the real kicker is the x -ray, right?

Exactly.

The text warns that, initially, scaphoid fractures can be invisible on x -ray.

They're a cult.

So if a patient has a foosh history and they have pain in the anatomic snuff box, that little hollow at the base of the thumb, you treat it as a fracture, even if the x -ray looks perfectly normal.

But you cast them anyway.

You cast them, you repeat the x -ray in two weeks.

You do not send them home saying it's just a sprain.

That's a mistake you can't afford to make.

It's a career -saving tip right there.

Next up, cols fracture.

This is also a foosh entry.

But instead of the carpal bone, it's the distal radius, the big forearm bone, right near the wrist.

Okay.

The text highlights two populations here.

Adolescents, because they're active and their bones are still growing.

And older adults, specifically those with osteoporosis, whose bones are more brittle.

The classic silver fork deformity.

Right.

The wrist gets pushed back.

And from the side, it looks just like a dinner fork.

And finally, the boxers fracture.

Similar to the Bennett, this is a punching injury.

But instead of the thumb, it's the fifth metacarpal, the one on the pinky side.

So it punches a wall.

And the knuckle of the pinky finger snaps or depresses.

So moral of the story, don't punch walls and try not to fall on your hands.

Easier said than done.

But yeah, that about covers it.

Before we leave this section, the text mentions cumulative injury.

This is the whole overuse category.

Right.

This is the patient who comes in and says, I didn't fall.

I didn't punch anything.

It just started hurting.

It's repetitive microtrauma.

Carpal tunnel.

Carpal tunnel from typing tennis elbow from tennis, but also from using a screwdriver all day.

It's thousands of small insults that add up to one big pain.

Let's move to section two.

Evidence -based practice and systemic clues.

There is a specific deep dive in the text here regarding a study.

Fornari et al.

from 2013.

It's about childhood obesity and fractures.

This is a fascinating bit of research that really highlights how our changing population health affects injuries.

They looked at kids with elbow fractures.

Specifically, they compared supercondylar fractures, which are above the elbow versus lateral condyle fractures, which are on the outside edge of the elbow.

And what did they find?

They found that obese children were significantly more likely to sustain lateral condyle or LC fractures.

In the study, the LC group had a much higher BMI.

Something like 37 % were obese compared to only 19 % in the other group.

Wow.

Why does that matter?

Is a lateral condyle fracture worse?

It is more complex.

It involves the joint surface itself, so it's harder to treat, and it has a higher risk of complications like non -union or issues with the growth plate.

Do we know why obesity would cause this specific type of break?

Was physics.

Force equals mass times acceleration.

A heavier child falling generates significantly more force on impact.

Plus, the mechanics of how they fall might be different due to their body habitus.

It's a really crucial insight because when you see an overweight child with elbow pain, your index of suspicion for this more severe type of fracture needs to be higher.

Now, let's play detective with timing and swelling.

The text gives us a swelling timeline.

I love this because it's so logical.

It is.

It's pure physiology.

The question you need to ask is, how fast did it swell?

Scenario A.

The patient twists their knee or wrist, and it balloons up immediately.

We're talking within two hours.

Immediate swelling almost always means blood.

Hamarthrosis.

Blood vessels have been broken.

This suggests a significant injury like a fracture or a complete ligament tear that ripped a vessel.

It's trauma.

Scenario B.

They twist it.

It hurts, but the swelling shows up that night or the next morning, say, six to 24 hours later.

That delay tells you it's not blood.

It's synovial fluid.

The joint is irritated, so it starts producing extra fluid to protect itself.

Right.

That points to something like a meniscus tear, a mild sprain, or a subluxation.

It's a reactive swelling, not a traumatic one.

And scenario C.

Swelling after 24 hours.

That's pure inflammation.

That's the immune system marching in to clean up the mess.

So fast equals blood.

Medium equals fluid.

Slow equals inflammation.

Precisely.

It's a great little rule.

And while we are on timing, let's talk about stiffness.

The text calls it the morning stiffness rule.

Yeah.

And this is the key to differentiating wear and tear from autoimmune.

It's a fundamental split.

So explain the difference.

OK.

If you have osteoarthritis, or OA, that's the wear and tear,

you might be a little stiff in the morning, but you shake it off at maybe 15, 30 minutes at most.

Once you get moving, the joints kind of lube up and feel better.

Right.

However, if you have rheumatoid arthritis, RA, or lupus, these inflammatory conditions, the stiffness lasts.

It lasts an hour or more.

And the response to activity is the opposite, too, right?

Yes.

We call it the gel phenomenon.

In an inflammatory condition, the joint gels up when you rest.

So activity actually pumps the inflammatory fluid out and makes it feel better.

We say motion is lotion.

Motion is lotion.

But in mechanical problems, like a broken gear and a machine moving, it makes it grind and hurt more.

So to sum it up, inflammation gets better with movement, mechanical problems get worse.

That is such a clear distinction.

Now, systemic associations.

The hidden causes.

The text throws some real curve balls here, things you wouldn't necessarily expect to cause arm pain.

Yeah, the first one is immunizations.

The text mentions a delay here that really shocked me.

Yeah, six to eight weeks.

We all know your arm hurts the day after a flu shot.

That's normal.

It's a local reaction.

But the text notes that transient arthralgia, so joint pain,

can occur nearly two months after an immunization, especially in women.

So you have to ask.

You have to ask.

If you don't ask about vaccines from two months ago, you'll never connect those dots.

There are STIs, gonorrhea, and cremedia.

This is absolutely critical in young sexually active populations.

You might be looking at a swollen wrist and thinking sprain, but the cause could be disseminated gonococcal infection.

How does gonorrhea even get to the wrist?

It travels through the bloodstream.

And it loves large joints, wrists, knees, ankles.

The text notes it affects about 1 % to 3 % of infected patients.

The clue is often a skin rash, little pustules on the extremities.

If you see a swollen wrist and a few spots on the hand in a young person,

you have to ask the uncomfortable questions.

And chlamydia.

Chlamydia can trigger something called reactive arthritis.

The bacteria isn't actually in the joint, but the immune system goes haywire and attacks the joint as a response to the infection elsewhere.

The classic triad.

Exactly.

Can't see, can't pee, can't climb a tree.

Conchuctivitis, urethritis, and arthritis.

One last systemic note from the text.

The cortisone flare.

Yes.

This is a warning you absolutely have to give patients.

You inject cortisone to stop pain, but the text says 50 % of patients will have more pain for the first couple of days.

Why?

That seems so counterintuitive.

It's just volume.

You are injecting liquid into a very tight enclosed space.

It stretches the tissue before the medicine has time to kick in and reduce the inflammation.

So you have to warn them.

You have to.

Tell them.

It might get worse before it gets better.

If you don't, they will call you in a panic thinking you made a huge mistake.

Okay, section three.

The focused physical examination.

We've done a lot of talking.

Now we actually look and touch.

An observation begins the second you see the patient.

How are they holding their arm?

Are they guarding it?

The text notes that septic joints, infected joints are incredibly painful.

The patient will refuse to move that limb at all.

They'll look systemically ill.

And we circle back to check for referred pain again here.

Always.

Ask them to point with one finger.

Show me exactly where it hurts the most.

If they point to the deltoid, you check the shoulder.

If they point to their hand, you check the elbow or the neck.

The text also emphasizes looking for deformities to help distinguish between the different types of arthritis.

This is visual diagnosis.

In osteoarthritis, or OA, you look at the fingers.

You see bony bumps.

Hepatid nodes are at the DIP joints, the ones right near the fingernail.

Bouchard nodes are at the PIP joints.

The middle knuckle, they look knobby and hard.

And in rheumatoid arthritis, RA.

RA is soft tissue swelling.

It looks fusiform or spindle -shaped at the PIP joints.

It's spongy to the touch, not hard like bone.

And later in the disease, you see that classic ulnar deviation.

The fingers drift sideways toward the pinky.

Now, palpation.

We are feeling for heat, tenderness, and fluid.

The text distinguishes fluid types.

Pus versus a hematoma.

How can you tell the difference with just your fingers?

It's subtle, but pus from an infection feels thick.

The text calls it less fluctuant.

It doesn't slosh around easily.

A hematoma, which is blood, feels more gelatinous, like jelly.

And crepitus.

That's the crunch.

If you put your hand on a joint and move it and you feel or hear what feels like gravel grinding, that's crepitus.

It usually means that the tendon is rough and grating inside its sheath, a sign of tendonitis.

Now, I want to do a little theater of the mind segment.

The text uses figures 23 .1 to 23 .3 to show the key anatomy.

For our listeners, if you aren't driving, maybe close your eyes for a second.

Expert, take us inside the shoulder based on figure 23 .1.

Okay.

Imagine the shoulder blade, the scapula.

You have a bony roof on top called the acromeon.

Below that roof is the ball of the arm bone, the humerus.

Okay.

Between the roof and the ball is a tiny space.

Living in that space is the rotator cuff tendon and a little fluid sac called the bursa.

Now, imagine lifting your arm.

The ball rolls up.

If that space is too tight or if the bursa is swollen, it gets pinched against the roof.

Crunch.

That is impingement.

That's why overhead motion hurts so much.

Got it.

Now, the elbow, figure 23 .2.

The elbow is a hinge, but it also rotates.

Focus on the radius.

That's the bone on the thumb side.

The head of that bone is held against the elbow by a ring of ligament called the anual ligament.

It's like a button in a buttonhole.

If you pull a child's arm too hard, the classic nursemaid's elbow, the button slips partway through the hole.

The ligament gets trapped.

And the wrist, figure 23 .3.

The wrist is like a cobblestone street.

It's two rows of small irregular bones held together by this incredibly complex web of ligaments.

It's not one joint.

It's a dozen tiny joints all working together.

And that's why diagnosing wrist pain is so hard.

You have to figure out which specific cobblestone is loose.

Let's move to the special tests, which the test lays out in table 23 .1.

These are the maneuvers we use to provoke the pain and pinpoint the problem.

I'll name the test.

You explain the move and what it tells us.

First, the Urgescent Test.

This test is for Bicipital Tendonitis.

You have the patient bend their elbow to 90 degrees, you shake their hand, and then you ask them to turn their palm up or supinate while you resist them.

This motion fires the biceps muscle.

If the long head of the biceps tendon, where it runs in the groove of the shoulder, is inflamed, they will feel a sharp pain right in the front of the shoulder.

The Drop Arm Test.

This is for the Rotator Cuff.

Passively lift their arm out to the side up to about 90 degrees.

Then you ask them to lower it slowly.

If the tendon is torn, they can't control the descent.

The arm will just drop.

And what if it's a complete tear?

If it's a complete tear, they often can't even initiate the movement.

They'll do the Shrug Zine.

They'll hike their whole shoulder blade up to try to cheat the movement.

The Tennis Elbow Test.

This is for Lateral Epichondylitis.

We have their elbow bent.

You ask them to extend their wrist backward against your resistance.

You are firing all those extensor muscles in the forearm.

If their anchor point at the lateral epicondyle of the elbow is inflamed, they will yell.

The Finkelstein Test.

This one is famous.

And famously painful.

This is for Decrevanes Tennisinnovitis.

You have the patient make a fist with their thumb tucked inside their fingers.

Then you gently bend their wrist down toward the pinky side.

You're stretching those inflamed tendons at the base of the thumb.

If they have decrevanes, this is excruciating.

You have to be gentle.

And finally, the two big nerve tests.

Tinnel and Phelan.

Right.

Tinnel is for tapping.

You tap briskly over the median nerve of the wrist.

If you get a zinging or tingling sensation in the fingers, that's a positive tinnel sign.

It means the nerve is irritated.

And Phelan.

Phelan is the reverse prayer.

You have them put the backs of their hands together so their wrists are bent down at 90 degrees.

They hold that for 60 seconds.

If their fingers go numb or tingly, it's a positive test for carpal tunnel.

You're basically squeezing the carpal tunnel shut and provoking the symptoms.

Okay.

Section 4.

Labs and Diagnostics.

When do we actually order tests?

The text suggests a baseline, especially if you suspect something systemic.

You'd get a CBC, a complete blood count, to rule out infection or even leukemia.

Then an ESR and a CRP.

These are nonspecific inflammation markers.

So what do they tell you?

If they're high, it tells you something inflammatory is going on in the body.

It could be RA.

It could be an infection.

If they're normal, it makes a systemic inflammatory cause less likely and you lean more toward a mechanical problem.

And joint aspiration?

Sticking a needle in the joint?

Yeah, if a joint is swollen and you don't know why, you might tap it.

We send the fluid to the lab and look for a few key things.

WBC count for infection, crystals for gout, and then we do the string test.

Explain the string test.

So normal synovial fluid is gooey.

It has high viscosity because of a protein called hyaluronin.

If you drip it from the syringe, it should form a long cohesive string.

Okay.

If it drips like water, that means inflammation has broken down those proteins.

If it's thick like toothpaste,

that's probably pus.

And x -rays.

What's the golden rule the text emphasizes?

Two views.

Always.

An AP, which is front to back, and a lateral from the side.

You need a 3D understanding.

A dislocation might look totally fine from the front, but be clearly popped out on the side view.

One view is one view too few.

We have arrived at the finale.

Section five.

The differential diagnosis.

We've ruled out the emergencies.

Now we categorize the rest.

The text starts with category A musculoskeletal inflammation.

This is your tendonitis, which is inflammation of the tendon,

tenosynovitis, inflammation of the tendon sheath, and bursitis, inflammation of the bursa sac.

And how do we differentiate these?

The key here is distinguishing it from a problem inside the joint itself.

In these conditions, active motion hurts because the muscle is pulling on the inflamed tendon.

But passive motion, where you move their arm for them, might be okay.

In arthritis, the joint hurts no matter who moves it.

And osteomyelitis, bone infection, pops up here again.

Just to remind us, a bone infection causes constant worsening pain.

And the patient will have exquisite point tenderness right on the bone itself.

Category B, joint inflammation.

This is the arthritis showdown.

We covered the nodes and stiffness, but let's just recap the classic presentations.

OA, osteoarthritis, asymmetric, usually older age.

It's mechanical pain, so it's worse with use.

RA, rheumatoid arthritis, symmetrical.

It's systemic, so you get fatigue, weight loss.

And it's inflammatory pain, so it's often better with use.

Category C, trauma and overuse, broken down by region.

Let's do a rapid fire on the specifics we haven't covered in depth yet.

Let's start with shoulder dislocation.

Anterior is by far the most common.

The arm is held slightly away from the body.

The classic sign is they cannot touch their opposite shoulder.

Posterior dislocation is rare.

You'd think seizures or electrocution.

With that one, they can't rotate the arm outward.

Elbow, olecranoma bursitis.

Student's elbow.

The big, soft, fluid -filled sac right on the tip of the elbow.

Usually from leaning on it too much or a direct bang.

It looks dramatic, but is often not very painful unless it gets infected.

Wrist, ganglion cyst.

A common bump on the wrist.

It's filled with a thick, jelly -like fluid, the diagnostic trick.

Shine a flashlight on it in a dark room.

If it glows or trans -luminates, it's a fluid -filled cyst.

If it's dark, it's a solid mass.

Okay, last one.

Category D, systemic, nerve, and other miscellaneous causes.

First, fibromyalgia.

This is a diagnosis of exclusion.

You have widespread pain, fatigue, sleep issues.

But the key is the physical exam is normal.

There's no swelling, no redness, just these specific tender points.

Deep putrid contracture.

This is a genetic condition, often in people of Northern European descent.

The fascia in the palm of the hand thickens and shortens.

It pulls the ring and pinky fingers down toward the palm.

The test is, can you flatten your hand on the table?

They can't.

Sickle cell disease.

In infants, you can see something called hand foot syndrome, which is swollen, painful hands and feet.

In adults, it causes these deep vaso -occlusive crises with terrible bone pain.

And finally, nerve entrapment.

We know carpal tunnel.

What is thoracic outlet syndrome?

This is compression of the nerves and blood vessels way up in the neck and shoulder area as they exit the chest.

The key symptom is that it happens when the arms are overhead or when they're sleeping with their arm up against their head.

You might even hear a brute, a whooshing sound, if you listen with a stethoscope above the collarbone.

And cubital tunnel syndrome.

That's the funny bone nerve.

It's the ulnar nerve getting trapped in its little tunnel at the elbow.

The classic symptom is numbness and tingling in the pinky and half of the ring finger.

Wow.

We have really covered the map.

From PQRST all the way to the specific anatomy of the snuffbot.

That's a lot.

But having that structure safety first, then history, then examine it, keeps you from getting lost in the weeds.

Any final words of wisdom for our listeners to tie this all together?

Just this.

Remember the referred pain concept.

The arm is so often just the messenger.

The real problem could be the neck, the heart, or a systemic infection.

Don't get tunnel vision on the wrist and miss the gonorrhea.

You have to look beyond the limb to treat the limb.

Look beyond the limb.

I love that.

That's a great place to end.

Thank you so much for breaking all of this down with us.

My pleasure.

And warm thank you from the entire last minute lecture team.

We really hope this deep dive helps you master the puzzle of chapter 23.

Until next time, keep learning.