Common Radial Nerve Injuries To Study For the Hand Therapy Exam - Hand Therapy Secrets

Common Radial Nerve Injuries To Study For the Hand Therapy Exam

Do you ever get cases where they never seem to get better no matter what you do?

That can often happen with radial nerve types of injuries.

It’s important to know the names of nerves, how they travel – the basic anatomy of a nerve.

I often talk about how having a certain amount of knowledge is essential. Still, you need to apply what you know to get results as an occupational therapist specializing in hand therapy. If you can think through the problems, it will help you not feel like you need to memorize all the details.

Evaluation:

If you’re seeing someone on evaluation, what are you looking for? What are the key questions you want to ask?

What does a radial nerve injury suppose to look like potentially?

What are the problems, and how are you supposed to progress?

That’s where your protocols are coming in. You need to know how to talk to your patients in terms of what you would expect their recovery to look like, based on what you know about nerves, what you know about the injury, and bones and ligaments.

What’re the complications of radial nerve injury based on the type of injury? For example, was it lacerated, tractioned, or compressed?

Treatment:

For your plan of care, what are you supposed to do?

How are you supposed to treat this particular radial nerve injury?

When are you supposed to apply hands-on versus exercise-based treatments?

How do you progress with somebody?

All of this is applied knowledge based on what you know about nerve injuries, the actual nerve, and then you have to ensure that you involve your patients in their plan to ensure the best results.

For the Hand Therapy Exam, most people will have you thinking you need to memorize all the details. While it’s extremely important to remember the muscles innervated by which nerve and the order in which it is innervated, it’s also important that you know how to apply that knowledge to answer the questions on the exam.

There will be some little key differences, like, “Oh, if you read it from this chapter, or in this textbook,” or you’re watching a ton of YouTube videos. My advice is to pick one source to remember from – and stick with that. Otherwise, you will become confused.

I love YouTube. I go there for videos and create videos for YouTube. But sometimes, there’s too much information. So now your brain is having to filter all the information and be like, “Oh, which one do I need, which one’s correct?”

What happens is you end up wasting a lot of time. You’re wasting a lot of energy and mind space, trying to figure out which one you should pay attention to. So pick one resource and stick with it if you are studying for the Hand Therapy Exam.

Common Radial Nerve Injuries You Might See as a Certified Hand Therapist:

  1. Radial Nerve Palsy due to Humeral shaft fractures.
  2. “Saturday Night Palsy”
  3. Radial Tunnel
  4. Compression of the SBRN

Some common injuries with the radial nerve are humeral shaft fracture or when the nerve wraps around and gets compressed, something called “Saturday night palsy.”

I always like to think through in the order in which it innervates. One – triceps, two – anconeus, three – brachioradialis, four – ECRL, five – ECRB.

If you’re dealing with a humeral shaft fracture right along with that shaft, you’re going to see everything affected below that. If it’s a Saturday night palsy, it might be a little bit higher up. “Okay, is anything above that affected, or is it just everything below?”

Then we think about the wrist. What injuries will be affected if you hurt the radial nerve at the forearm or wrist? it might just be the dorsal digital nerves that would be affected. It wouldn’t affect anything muscular above. So everything would be sensory below.

Just keep in mind where the radial nerve travels.

In terms of sensory branches, there are many sensory branches, and if I’m looking at someone in the front, I would feel…if something were wrong with my nerves, I would feel it around that deltoid area, right, sensory branch around that deltoid area. I’d feel it along the side of my thumb, the radial side of my thumb. Many more sensory branches come out on the backside, but I would feel it a lot more posterior on the backside. I’d feel a lot more along the back of that tricep, and then, I would feel it along with the wrist group. Then I’d feel it along the back of the hand. That’s where you’ll tend to see your small branch or the radial nerve and all that good stuff.

I’ve seen a couple of different variations in the posterior interosseous nerve, but it’s right around the elbow. One part will say distal to the brevis, affecting all the motor nerves here. When the radial nerve divides at the distal of the elbow, it branches off into the superficial and then the deep. The deep is a posterior interosseous nerve. Then, the superficial is where you’re going to see your dorsal radial sensory nerve.

Let’s think about what happens when a laceration, traction, or compression happens.

We think about what happens to nerves and what are potentially the problems. For example, especially in the radial nerve, it can get lacerated, it can get tractioned, and it can get compressed.

If we take what we know from looking at it linearly, we divide it into a high and low radial nerve injury. This outer circle is your high, and the inner circle is your low. So in your high radial nerve injury, you’re going to see your triceps, your anconeus, your brachioradialis, and your extensor carpi radialis longus. In your low radial nerve, you’ll see your extensor carpi radialis brevis, your supinator, your EDC, your EDM, your APL, your EPL, your EPB, and your EI.

Let’s think about high and low radial nerve injury.

If you know that with your nerve innervations, you should be able to see, based on what you see clinically, you can know essentially almost where that nerve is injured, and whether it’s going to be high or low, you can essentially predict what’s going on.

With a high radial nerve injury, what would happen? If you hurt it high, you would see potentially no tricep, you’d see potentially no brachioradialis, you’d potentially see no longus extensor or longus. So if you start to see all of these muscles on the high, you know not only will you not see them, but you won’t see anything below them.

Then what happens? If you’ve lost a wrist extensor, but now you’ve lost all of your wrist extensors, you’ve lost your supinator. So, sometimes a supinator is a little tricky because your biceps is your strongest supinator. Your biceps might make it look like you have supination, but really, if you don’t have wrist extension, you probably don’t have the actual supinator, and you can’t get it started. Then you’re going to lose not only total wrist extension, but you’re not going to see any finger extension, and you’ve lost these extra tendons that help you to isolate even further finger extension.

**This was a snippet of one of my lectures in the Hand Exam Prep program.

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Author:

Hoang Tran

“I help Occupational Therapists develop their skills and grow their confidence in Hand Therapy. No matter where you are on your journey, build a happy and fulfilling career of your dreams. I’ll help you.”