The Biceps Femoris
HIDEInteractive Transcript
0:00
Let's talk a little bit more about the biceps reems.
0:03
As the name denotes, it has two heads, a short head,
0:06
more anteriorly, which originates from the femur
0:09
and a long head more posteriorly, which originates from the,
0:13
uh, ish scale tuberosity.
0:15
And I think you heard, uh, more about that from Dr.
0:18
Patris talk and from cases from Dr. Smitherman.
0:22
But nevertheless, the biceps fems is the strongest
0:25
hamstring, uh, muscle of,
0:27
of the hamstrings at the posterior aspect of the knee.
0:30
It two forms a complex as it inserts on the,
0:34
uh, fibular head.
0:36
Remember, I've already shown you that it is intimate
0:38
with the fibular or lateral collateral ligament.
0:41
And this one paper actually studied all the various, um,
0:44
fibers of the biceps femoris
0:47
and found it that it not only attached to the fibular head,
0:51
but it also had anterior arms which
0:53
inserted on the proximal tibia.
0:54
Hence, this is why sometimes it's believed
0:57
that the biceps fems may contribute to the development
1:00
of sigon fractures.
1:02
But again, notice how the fibular collateral ligament is
1:05
sandwiched in between the biceps fems.
1:07
And in the same paper, they sort
1:09
of mapped out topographically how the biceps fems is related
1:12
to the fibular collateral ligament.
1:14
And you can see various contributions of both short head
1:17
and long head surrounding this fibular collateral ligament.
1:22
This has also been, uh,
1:24
described in the radiology literature as well.
1:26
Uh, they've described these anterior arms
1:29
and then as well these direct arms which insert directly
1:33
onto the fibula.
1:36
So if you look at this closely, again,
1:38
I just wanna kind of drive this point in.
1:40
As you follow your femoral, uh,
1:43
your fibular collateral ligament inferiorly, you will see
1:46
that indeed it intertwines with the biceps fems tendon.
1:50
And notice the biceps fems tendon is sending arms anteriorly
1:54
that insert on the proximal tibia.
1:56
So a very complex structure, uh,
1:59
at the lateral aspect of the fibular head.
2:04
Here's an example of a patient with a biceps fem avulsion.
2:07
Our start with the coronal images, uh,
2:10
pretty clear what's going on here.
2:11
You can see a lot of edema at the
2:13
lateral aspect of the knee.
2:14
And as we follow this biceps femes, uh, muscle
2:17
and tendon, again, we see
2:19
that it doesn't insert on the fibular head.
2:21
We can see as we move back
2:23
and forth through these coronal images, in fact,
2:25
the fibular collateral ligament is intact,
2:27
which is very unusual on our axial images.
2:31
As we follow this inferiorly,
2:33
let's follow the fibular collateral ligament.
2:35
As we move more inferiorly, we can follow it.
2:37
There it is, and we follow it
2:39
to its attachment naturally inserts on the fibula.
2:42
But what is missing The bicep s fems tendon
2:45
and that seen more superiorly here.
2:49
So again, these, in these isolated f um, biceps fems,
2:52
this should say biceps femoris, uh, injuries are very rare,
2:57
uncommon, seen, almost exclusively in males, usually
3:00
during heavy lifting activities.
Donald Resnick, MD
Professor Emeritus, Department of Radiology
University of California, San Diego
Mini N. Pathria, MD, FRCP(C)
Division Chief, Musculoskeletal Imaging
University of California San Diego
Eric Y. Chang, MD
Adjunct Professor, Radiology
University of California, San Diego
Brady K. Huang, MD
Clinical Professor of Radiology
UC San Diego Medical Center
© 2026 Medality. All Rights Reserved.
