0:00

Now sometimes the anatomy can be very complex,

0:03

and I think the most complex anatomy

0:06

that we encounter is at the rectus femoris.

0:09

And, uh, I believe this anatomy is unique, uh,

0:12

to this particular muscle where we actually have a muscle

0:15

inside muscle configuration.

0:17

Around the periphery, we have the direct head of the rectus,

0:22

remember, that's the portion that's coming off the anterior

0:26

inferior iliac spine.

0:28

And then centrally, we have the tendon

0:30

and muscle fibers from the indirect head.

0:33

And that is the part arising from the reflected tendon

0:37

that inserts along the superior hip capsule.

0:40

And you can get a variety of different injuries

0:44

to this depending upon where the damage is taking place.

0:48

That inner muscle, which is the indirect head portion, is

0:52

by penate and tends to strain quite frequently

0:57

and can pull back and create a void, uh, distally.

1:01

And then the direct head, which is more superficial,

1:04

is a unipennate uh, structure, again,

1:07

with its tendon shifting positions, uh,

1:10

depending upon the level you are, uh, within the leg.

1:13

So this is a classic example here

1:17

of an injury involving the indirect head.

1:20

The tendon, which is a big central tendon

1:22

that you look at when you're looking at Mr,

1:25

is wavy and redundant.

1:27

There's edema in the muscle

1:29

and there's that characteristic fluid filled void at the

1:32

bottom of the injury.

1:34

Corresponding ultrasound, showing the thickened irregular

1:39

and EMTs fibers in transverse section

1:42

and then lower down the void created by the retraction

1:47

of the terminal, end of the indirect head, uh, tendon.

1:51

And there's a very nice, uh, rad source.

1:54

Um, this image is taken from that, um, webinar

1:58

by RAD source, uh, just showing you the different positions

2:02

of the direct and indirect head, uh, components

2:05

and the positions of the fascia, uh,

2:09

along the different lengths of the, of the tendon.

2:12

So it can have a quite a variable appearance depending

2:15

upon where you are.

2:16

Here's just a nice example.

2:18

This is the tendon here from the indirect head,

2:22

vertically oriented.

2:23

This is a direct head injury with hematoma,

2:27

somewhat bright on our proton density images.

2:30

And like many muscle injuries, we have a little bit of fluid

2:34

around the surface of the muscle

2:36

and fluid between that muscle

2:38

and the adjacent, uh, musculature.

2:40

So this is a, a typical type of injury.

2:43

And from that article, again,

2:45

we're right about at this level

2:46

where you're gonna be seeing the indirect head, uh,

2:49

coming down as a comma.

2:50

And again, I encourage you when you get a really good

2:53

quality Mr.

2:54

And somebody that's muscular,

2:56

but still has enough fat to separate out the muscles

2:59

that you keep a reference file, uh, for yourself.