So it's important to really understand
the nerves that pass through the elbow
understanding the location of the nerves to give
you a better idea on when the might be impinged.
Patients that complain about certain weaknesses, numbness
and tingling of the hand or the forearm or radiating pain
could potentially have nerve compression and so
understanding the route of these nerves are important
to better understand where they
may be potentially compressed.
So the median nerve lies deep to the antecubital
fossa, it is medial to the biceps brachii.
The radial nerve is lateral to
the biceps and brachialis muscle.
whereas the ulnar nerve runs more
posteriorly and posterior to
the medial epicondyle running
through the ulnar groove.
So the ulnar nerve innervates the ulnar collateral
ligaments and supplies the flexor carpi ulnaris
The median nerve passes between the
brachialis and the bicipital aponeurosis
to supply the pronator muscles and most
of the wrist and hand flexors.
The radial nerve has a medial and posterior
branch that supplies the triceps, anconeus
and the posterior and
anteriolateral joint capsule.
They also have a lateral branch that pierces the
lateral intermuscular septum and that supplies
extensor carpi radialis longus
and also continues on as the
posterior interosseous nerve.
So somatic dysfunctions can
occur at the elbow joint.
These dysfunctions could be due
to injury or repetitive motion.
Most of the time it's associated with some
sort of inflammation and muscle spasms
and sometimes would be compensation for injuries
outside of the elbow, at the wrist or shoulder.
So when we're trying to diagnose a somatic
dysfunction we're making it based on motion testing.
And so, if we have a restriction
in flexion or extension,
that could lead us to make a diagnosis
of a flexion or extension dysfunction.
So remember, somatic dysfunctions
are named for its freedom.
So if I have a flexion dysfunction of the elbow,
that means that there's a preference for flexion
and that there's a limited
range of motion in extension.
The opposite is true in
an extension dysfunction
The elbow prefers extension but then has difficulty
reaching the full range of motion in flexion.
At the radial ulnar joint, we have
pronation and supination as motions.
If we have restrictions in
a pronation or supination,
that could lead us to diagnosing
somatic dysfunctions in that motion.
So if I have a pronation
we're gonna have a restriction in supination
because pronation is the freedom of motion.
Now, there's an association between the radial head
positioning and how the forearm likes to glide.
So, a radial head that is stuck in a
posterior position prefers pronation
whereas a supination dysfunction
has restriction in pronation
and the radilal head is not
going to prefer anterior glide.
So another way to diagnose radial
head somatic dysfunction specifically
is to contact the radial
head and then motion test.
So when we motion test, what we're going to do
is we're going to passively move the forearm
into supination and pronation and while
we're monitoring at the radial head,
we're gonna see which way does the
movement of the radial head feel freer
Does the radial head move more posterior in pronation
or does it move more anterior in supination?
So that is one way to passively test
freedom of motion at the radial head.
An alternative way is to
do an active screening.
So in an active screening, we're gonna
have our patients kinda put their elbows
against their body and have their
elbows flexed at 90 degrees.
We're gonna start at neutral and then we're gonna ask the
patients to pronate both sides and supinate both sides.
And so what you're looking for,
is there a freedom of motion
to either pronation or supination
as the patient does that.
The diagnosis is made with the
side of increased freedom.
An easy way to remember the direction of motion
of the radial head with pronation and supination
is a mnemonic PPAS, 'cause if you'll remember
it, it'll help you pass your examinations.
Posterior is associated with pronation and anterior
radial head is associated with supination.
So let's apply the knowledge
that we just covered.
A 45 year old tennis player presents
with right lateral elbow pain.
On active range of motion testing you find that he is
only able to pronate his right elbow about 5 degrees
while having full range of
motion with supination.
What is his radial head somatic
So here, we have the tennis player who
is unable to fully pronate his elbow.
So if you are unable to fully pronate your elbow,
you have a freedom of motion in supination.
Remember back that we have the radial head is
more anterior, that's associated with supination
while posterior is
associated with pronation.
So in this case, we have a right anterior
radial head somatic dysfunction.
This is a case where we have a 14-year old male presents
with right elbow pain after tripping and falling 2 days ago.
He states that he fell forward on his
right wrist with his elbow extended.
X-rays of the elbow were negative for
fracture and on passive motion testing,
there was a decreased in
right elbow supination.
So what is the radial
head somatic dysfunction?
So here, our patient fell with
outreached hand forward.
And so, what you notice here is that the forearm is
pronated, we have a crossing of the ulna and radius.
So when you fall forward and land on your
wrist, a lot of times that jams the radius
into the elbow and
creates a dysfunction.
If it's crossed over, then it's more
posterior because our forearm is pronated.
and so that would lead to an increased risk
of a posterior radial head dysfunction.
The motion and characteristics
on testing also confirmed that
since there was decreased right elbow supination,
the freedom of motion was pronation.
Thus, giving us our diagnosis of
a posterior radial head
The opposite would be true if we
were to fall with hand behind us
because our forearm is now straight
and where our forearm is supinated,
when we jam the elbow in a supinated position
that might cause anterior radial head.