L.E. Muscles Actions, O's & I's (Class #1)

Question 1

Psoas Major*

Muscle #42
TG pg. 332
ACB pg. 48

(No Palpation)

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

Answer 1

ORIGIN(S):
- The lumbar vertebrae (Bodies, discs and transverse processes of L1-L5)

INSERTION(S):
- Lesser trochanter of the Femur

ACTION(S):
1- Flexion of the trunk at the waist;
2- Flexion of the thigh at the hip,
3- Lateral rotation of “ “ “ “ “

Question 2

Iliacus

Muscle #41
TG pg. 332
ACB pg. 48

(No Palpation)

> > > Action(s) Only

Answer 2

ACTION(S):
1- Flexion of the thigh at the hip
2- lateral rotation of “ “ “ “ “

================================

> > > No Asterisk * means that memorizing O’s & I’s is not required. They are added below just for fun «<

ORIGIN(S):
1- Iliac crest and
2- Iliac fossa of the Ilium

INSERTION(S):
- Lesser trochanter of the Femur (via the tendon of Psoas Major)

Question 3

Gluteus Maximus*

Muscle #40
TG pg. 315
ACB pg. 59

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

Answer 3

ORIGIN(S):
1- PSIS
2- Sacrum, and
3- Coccyx

INSERTION(S):
1- Gluteal Tuberosity of the Femur
2- Lateral Condyle of the Tibia (via the Iliotibial Band)

ACTION(S):
1- Forceful Extension of the thigh at the hip
2- Lateral rotation of the “ “ “ “

Question 4

Gluteus Medius*

Muscle #37
TG pg. 315
ACB pg. 59

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

Answer 4

ORIGIN(S):
- Exterior surface of the Ilium (between Iliac crest and superior Gluteal lines)

INSERTION(S):
- Greater trochanter of the Femur
(posterior border)

ACTION(S):
1- ABduction of the thigh at the hip
2- MEDIAL rotation of the “ “ “ “

Question 5

Gluteus Minimus*

Muscle #36
TG pg. 316
ACB pg. 59

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

Answer 5

ORIGIN(S):
- Exterior surface of the Ilium (between superior and inferior Gluteal lines)

INSERTION(S):
- Greater trochanter of the Femur
(anterior border)

ACTION(S):
1- ABduction of the thigh at the hip
2- MEDIAL Rotation of the “ “ “ “

Question 6

Tensor Fascia Latae*

Muscle #39
TG pg. 324
ACB 66

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

Answer 6

ORIGIN(S):
1- ASIS, and
2- Iliac crest (of the Ilium)

INSERTION(S):
- Lateral condyle of the Tibia
via the Iliotibial Band

ACTION(S):
1- Flexion of the thigh at the hip
2- ABduction of “ “ “ “
3- MEDIAL Rotation of “ “ “ “

(Also, maintains tension on the ITB)

Question 7

Piriformis*

Muscle #35
TG pg. 328
ACB pg. 59

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

(**See also: flash card for Lateral Rotators, aka “deep six”)

Answer 7

ORIGIN(S):
- Anterior surface of the Sacrum

INSERTION(S):
- Greater trochanter of the Femur

ACTION(S):
- Lateral rotation of the thigh at the hip

Question 8

The Adductor Group

Muscles #60, 61, 62 & 63
TG pg. 320

> > > Name Action(s) Only (no asterisk *)

*** For this class, we are considering all the ADDuctors as one group.
> Bonus points if you can NAME ALL FOUR ADDuctor muscles in order from superior to inferior.

Answer 8

ACTION(S):
- ADDuction of the thigh at the hip
============================

*** The four adductors, in order, are:
1- Pectineus
2- Adductor Brevis
3- Adductor Longus
4- Adductor Magnus

Question 9

Bonus question:
The lateral rotators, aka “The Deep Six”

***We are focusing on the Piriformis only in Kinesiology, but for funsies:
»> NAME ALL THE DEEP SIX
in order, from superior to inferior.

Answer 9

1- Piriformis,
2- Superior Gemellus,
3- Obturator Internus,
4- Inferior Gemellus,
5- Obturator Externus,
6- Quadratus Femoris

Question 10

Gracilis*

Muscle #64
TG pg. 320
ACB pg. 61

> Name the Origin(s), Insertion(s) and Action(s) of this muscle.

Answer 10

ORIGIN(S):
- Inferior Ramus of the Pubis

INSERTION(S):
- Medial condyle of the Tibia
(part of Pes Anserinus)

ACTION(S):
1- ADDuction of the thigh at the hip;
2- Flexion of the leg at the knee

Question 11

Bonus Questions:
- What 3 muscles have their insertions at the Pes Anserinus?

• Is the Pes Anserinus Medial or Lateral to the patellar region?

Answer 11

1- Sartorius (say it like you mean it!!!)
2- Gracilis
3- Semitendinosus

(In order, as the tendons appear from anterior to posterior)

• The Pes Anserinus is on the MEDIAL side of the leg/knee.