0:00

Okay, we're all set to go for the, uh, final lectures

0:04

of this course and one final case presentation.

0:07

And Minnie Patria is up again

0:10

and she's gonna talk about muscle disorders.

0:12

Now Minnie is good in, in everything,

0:14

but this is her real specialty, so

0:18

I am sure this will be a terrific, terrific, uh, lecture.

0:22

So many muscle disorders, all yours.

0:25

Thank you, Don. And thank you again for having me.

0:28

I'm sure everybody's getting tired.

0:30

It's Friday, it's been a long week.

0:33

So let's, uh, get started

0:35

and we'll talk, uh,

0:36

for the next 40, 45 minutes about muscle trauma.

0:40

I'm gonna focus on the acute muscle injuries,

0:42

particularly on muscle strain and contusion,

0:46

but I will show you some of these other abnormalities

0:49

because they also fall under the spectrum of muscle trauma,

0:52

including some of the more subacute

0:54

and chronic conditions that you may see

0:57

less, uh, frequently.

1:00

So let's start first by understanding the anatomy

1:02

of what we're dealing with.

1:04

I always like to think about injuries involving muscle

1:08

as being part of this muscle tendon emphasis bone unit.

1:12

So the muscle doesn't act alone.

1:15

The muscle acts to move our skeleton via the tendons

1:20

and those tendons insert the bone as an emphasis.

1:24

And when we look at this complex, we'll see

1:27

that injuries take place in different locations

1:29

depending on the age of the patient.

1:31

Uh, as I showed with the apophyseal injuries earlier

1:34

around the hip, childhood failure is often bony perote

1:39

or ATIs.

1:41

We've seen many times during this course

1:43

how failure in adults predominates in the area

1:47

of the tendon, which degenerates.

1:49

What I'm gonna be talking about today are the muscle

1:52

injuries involving the muscle and myo tendonous junction.

1:55

And those tend to predominate more in the younger

1:58

and middle aged adult, particularly those that, uh,

2:01

participate in athletic uh, activities.

2:05

Now in terms of muscle function, the muscle can function by

2:09

contracting and shortening, contracting

2:12

and lengthening, which is somewhat paradoxical,

2:14

but this is what happens when you are lowering the weight

2:18

and the muscle is firing,

2:19

but getting longer at the same time.

2:21

And muscle can also contract without changing length.

2:25

These are associated with different patterns of injury.

2:28

And interestingly, it's these eccentric injuries

2:32

where the muscle is being lengthened that lead to many

2:35

of the problems that we're gonna be looking at, uh, today.

2:39

So during muscle lengthening, the contraction is slower,

2:43

but it has a higher force than a concentric contraction.

2:47

And this is where we tend to see damage, both sort

2:50

of the slow chronic damage of delayed onset muscle soreness,

2:54

and also the damage of muscle strain,

2:57

which is essentially a tensile injury involving the myo

3:01

tendonous, uh, junction.

3:02

So keep that in mind.

3:04

Um, and uh, you just remember

3:07

that it's these eccentric lengthening movements

3:09

that are more important in terms of muscle injury.