Brush up on your Anatomy! No Googling This One!

[samiam]

32 yr old woman admitted to ER after a MVA. X-rays reveal multiple humeral fractures. Flexion and Supination of the forearm are severely weakened. Also exhibits loss of sensation to the lateral surface of the forearm. What nerve has most likely been injured?

 

[phideux]

No Google, just a guess, Brachial?

 

[samiam]

No Google, just a guess, Brachial?

Never heard of the brachial nerve

Well since no one seems to be interested I will answer for you: For reference, the entire posterior compartment (forearm and arm) is Radial nerve, The anterior arm is musculocutaneous and the anterior forearm is medial with a bit of ulnar.

When I think Flexion of the forearm I think a bit of biceps brachai and mostly brachialis which are in the anterior forearm, Supination of the forearm is mostly the biceps (You are supposed to supinate when you do barbell curls not just straight up!) again in the anterior forearm, as for the lateral surface of the forearm is innervated by the lateral antebrachial cutaneous nerve which we can trace back to the musculocutaneous then to the lateral cord and then the upper trunk then C5,C6 The lateral arm dermatome is C5 C6. All the evidence points to musculocutanous!

Learn something new each day! The body is amazing!

 

[Aprz]

I wish I knew enough anatomy to have had answer this. I think most of us wouldn't know without looking it up, lol.

 

[pcbguy]

Lateral in the anatomic position would be along the thumb side of the forearm. I believe that from about the level of the deltoid down the arm to the thumb is C6.

 

[JPINFV]

Lateral in the anatomic position would be along the thumb side of the forearm. I believe that from about the level of the deltoid down the arm to the thumb is C6.

Anatomic position: Hand at the side, palm forward.
Lateral upper arm: C5
Lateral lower arm, lateral hand: C6
Middle finger: C7
Medial lower arm, medial hand: C8
Medial upper arm: T1.

 

[Carlos Danger]

Musculocutaneous n.

 

[samiam]

I wish I knew enough anatomy to have had answer this. I think most of us wouldn't know without looking it up, lol.

Well I am in medical (not medic) school atm so maybe I was aiming a little two high. I would have thought some of the paramedics would have gotten it. I will come up with some that are a little more general.