Joint Actions and Muscle Contractions in 3 simple learning points

Joint Actions and Muscle Contractions in 3 simple learning points

In this blog, I am going to explain the fundamentals of joint actions and muscle contractions, in 3 simple learning points.

This is the area most learners freak out over, on their Level 3 Anatomy exam…. and I get it some of the questions are pretty complex (like the one used in the video).

From experience, it is not that you need a superior detailed memory, it is that you need to know the basic fundamentals of joint actions and muscle contractions. That’s why I’m going to teach you these fundamental 3 learning points:

Joint Actions and Muscle Contractions: The fundamentals

1. Flexion and Extension

You need to know 17 joint actions for your Level 3 Anatomy and Physiology exam. However, starting with the fundamentals, you definitely need to know the difference between Flexion and Extension.

All of our joints are in extension when we stand in a neutral position, with palms facing forwards.

All of our joints are in extension when we are in a foetal position – except shoulders which are in full flexion when arms are overhead.

So here is a memory hack to help you decipher between the two:

Extension = Elongated in Neutral position

Flexion = Foetal Position (+arms overhead)

Watch this on the video to get a clear visual

2. Muscle Fibre Direction.

It is crucial to have a good understanding of the muscle fibre direction of each muscle, these are the striations that run from one end of a muscle to the other.

If you know what way the muscle fibre runs, then you can predict the joint action it creates.

Imagine the striations are a tug of war rope, with a team sat on each attachment point.

Joint Actions and Muscle Contractions in 3 simple learning points - Muscle fibre direction

When the muscles contract, when they shorten and lengthen they lengthen along the direction of the muscle fibre striations.

[TIP: If you are looking for clear images of the muscles, then check out our muscle memory flashcards:

3. Concentric & Eccentric Contractions.

Most people think of a muscle contraction as the muscle shortening. However, there are 2 types of contractions for each muscle, one that gets longer and one that gets shorter.

You need to know that a concentric contraction is the muscle shortening,

… and eccentric contraction is the muscle lengthening.

You can remember this using…

Concentric = Collapsing (shorter)

Eccentric = Elongating (longer)

Mock Question:

Now you have learned the fundamentals, let’s put it to the test. Can you answer this mock question?

Joint Actions and Muscle Contractions Mock Questions

Pop a comment with your answer below, and then watch the video for the answer.

If you want more mock questions for your  Level 3 Anatomy and Physiology exam, then click the link to download 101 mock questions, to help you prepare.

Please leave a comment below telling us which joint action confuses you most. I’m looking forward to reading and replying to your comments below.

If you liked this video make sure you hit like, share with your friends and be sure to subscribe to our Channel.

Thank you for watching

See you in the next video


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