What are "lateral and medial" fingers?

[Lothric]

Hey,

1. So when you injure your median nerve you do lose flexion of lateral fingers. And when you injure your ulnar nerve you lose flexion of medial fingers. Nowhere on the Internet can I find what is meant by lateral and medial fingers.

2. Is there an easy way to remember what flexion and extension indicate with respect to the wrist? I know that flexions decrease the angle between a segment and its proximal segment and vice versa for extensions, but what is the proximal segment in the context of the wrist? Is it the ventral or dorsal aspect of the forearm? Depending on what you define as the proximal segment, flexion could indicate a downright movement of wrist but also an upright one if we say that the dorsal forearm is the proximal segment for the latter. On the other hand, with the angle definition put aside, there is the anterior/posterior direction definition for flexion and extension, respectively. Is the wrist where you want to use the this definition, maybe?

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[TheOther]

Hey,

1. So when you injure your median nerve you do lose flexion of lateral fingers. And when you injure your ulnar nerve you lose flexion of medial fingers. Nowhere on the Internet can I find what is meant by lateral and medial fingers.

2. Is there an easy way to remember what flexion and extension indicate with respect to the wrist? I know that flexions decrease the angle between a segment and its proximal segment and vice versa for extensions, but what is the proximal segment in the context of the wrist? Is it the ventral or dorsal aspect of the forearm? Depending on what you define as the proximal segment, flexion could indicate a downright movement of wrist but also an upright one if we say that the dorsal forearm is the proximal segment for the latter. On the other hand, with the angle definition put aside, there is the anterior/posterior direction definition for flexion and extension, respectively. Is the wrist where you want to use the this definition, maybe?

Everything is based on the anatomical position. In the case of the hand and wrist, it's palm forward. So thumbs are lateral and pinkies are medial. As you said, wrist flexion is in the same direction at elbow flexion (anterior motion).

 

[YouScrewedup]

Yep what was said above. Also median nerve injury involves your 1st to 3rd digits and 1/2 of the 4th
The other 1/2 is ulnar plus the 5th digit (pinky)

As was also said above, in anatomical position ie palms up, when you flex at the elbow your forearm is coming towards the body. So therefore the same thing happens with the distal wrist joint, with the hand coming towards the body.

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[Lothric]

Thanks!

So thumbs only are lateral and 1-4 digits would be medial (not only the pinkies)?

FA says a median nerve injury causes loss of sensation over thenar eminence and dorsal and palmar aspects of lateral 3 1/2 fingers with proximal lesion. I read 3 1/2 as the first 3 lateral fingers + 1/2 continuing laterally (4th (pinky)), but that doesn't seem right.

 

[TheOther]

Thanks!

So thumbs only are lateral and 1-4 digits would be medial (not only the pinkies)? I think I got it now!

Nahhh. Don't think about it in those terms. I was giving you examples. If a question talks about lateral fingers, you can assume 1st and 2nd digits (thumb/index fingers). Medial fingers 4th and 5th digits (ring/pinky fingers). The middle finger is the middle finger.

 

[Lothric]

Nahhh. Don't think about it in those terms. I was giving you examples. If a question talks about lateral fingers, you can assume 1st and 2nd digits (thumb/index fingers). Medial fingers 4th and 5th digits (ring/pinky fingers). The middle finger is the middle finger.

Thanks man, I sure got it now!

Also edited my previous post above slightly after your post. Hopefully somebody can help me understand that too!

 

[TheOther]

Thanks man, I sure got it now!

Also edited my previous post above slightly after your post. Hopefully somebody can help me understand that too!

Thumb is the 1st digit. So when it says lateral 3 1/2, it means thumb, index, middle and lateral half of the ring.

 

[Lothric]

Thanks man!

 

[Mad Jack]

Hey,

1. So when you injure your median nerve you do lose flexion of lateral fingers. And when you injure your ulnar nerve you lose flexion of medial fingers. Nowhere on the Internet can I find what is meant by lateral and medial fingers.

2. Is there an easy way to remember what flexion and extension indicate with respect to the wrist? I know that flexions decrease the angle between a segment and its proximal segment and vice versa for extensions, but what is the proximal segment in the context of the wrist? Is it the ventral or dorsal aspect of the forearm? Depending on what you define as the proximal segment, flexion could indicate a downright movement of wrist but also an upright one if we say that the dorsal forearm is the proximal segment for the latter. On the other hand, with the angle definition put aside, there is the anterior/posterior direction definition for flexion and extension, respectively. Is the wrist where you want to use the this definition, maybe?

Legit question, how did your school not train you in this? This is literally day one anatomy, that anyone could make it through preclinical without knowing it is a poor reflection on institutional standards (and no fault of your own).

 

[Lothric]

Legit question, how did your school not train you in this? This is literally day one anatomy, that anyone could make it through preclinical without knowing it is a poor reflection on institutional standards (and no fault of your own).

We have not begun anatomy yet. I'm only 2 semesters in. The anatomy begins on the 27th but I'm already beforehand trying to learn the latin nomenclature, pathogenesis (we don't even have pathology until semester 3) etc. Besides, I never go to lectures but jump straight into what's high-yield (which comes with other problems, like not knowing the basics at first, but that's another story).

 

[Mad Jack]

We have not begun anatomy yet. I'm only 2 semesters in. The anatomy begins on the 27th but I'm already beforehand trying to learn the latin nomenclature, pathogenesis (we don't even have pathology until semester 3) etc. Besides, I never go to lectures but jump straight into what's high-yield (which comes with other problems, like not knowing the basics at first, but that's another story).

Are you in a six year school outside the US or something? Anatomy is literally the first subject we cover at every school I know of here, it's kind of foundational to learning everything else.

Also, the difference between a 220 and a 250 is the "low yield" stuff. Master high yield if you want to pass, but master everything if you actually want to do well. The best way to master everything is ground up, not top-down.

 

[Lothric]

Yes, the medical schools here in Sweden take 5,5 years to go through. No rush here

 

[Mad Jack]

Yes, the medical schools here in Sweden take 5,5 years to go through. No rush here

Oh that makes sense. Your first year and a half are basically our undergraduate prerequisites.

 

[Lothric]

Oh that makes sense. Your first year and a half are basically our undergraduate prerequisites.

You could say that! One half year (usually semester 8 in the medical schools here) is also completely devoted to research and nothing else. I don't know if you guys have something similar to that. Planning on doing it in a lab in the US somewhere to start expanding my contacts