Neck & Torso Muscles Actions, O's & I's (Class # 4-B)

Question 1

84. Sternocleidomastoid*

TG pg. 244-245

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

Answer 1

Origin:
1- Manubrium
2- Medial third of the clavicle

Insertion:
1- Mastoid process
2- Superior nuchal line

Action:
1- Flexion of the head at the neck (bilaterally)
2- Lateral flexion of the head at the neck (unilaterally)
3- Rotation (to opp. side) of the head at the neck (unilaterally)

Question 2

• 82. Splenius Capitis

TG pg. 203-204

> Name the Action(s) of this muscle.

(Note: Often injured in whiplash accidents. Commonly involved in morning stiffness.)

Answer 2

Action:
1- Extension of the head at the neck (bilaterally)
2- Lateral flexion, (unilaterally)
3- Rotation of the head at the neck (unilaterally)

Question 3

79, 80, 81. Scalenes
(anterior, middle, and posterior)

TG Pg. 246-249

> Name the Action(s) of this muscle.

Answer 3

Action:
1- Elevation of the ribs (bilaterally)
2- Lateral flexion of the head at the neck (unilaterally)

Question 4

• 78a, b, c. Erector Spinae Group (Erectors)

TG pgs. 196-199

> Name the Action(s) of these muscles.

Answer 4

Action:
1- Extension of the head at the neck**
2- Extension torso at the waist**
3- Maintenance of upright posture**
**(bilaterally)

4- Lateral flexion of head at neck
5- Lateral flexion of torso at waist
6- Rotation of the torso at the waist
*(unilaterally)

Question 5

89. Rectus Abdominis*

TG pg. 209-212

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

(Note: See diagrams for fiber direction)

Answer 5

Origin:
1- Xiphoid process
2- Ribs 5-7

Insertion:
1- Pubic symphysis
2- Pubic crest

Action:
1- Compression of the abdominal contents
2- Flexion of the torso at the waist

Question 6

• 88. Transverse Abdominis

TG Pg. 211

> Name the Action(s) of this muscle.

(Note: See diagrams for fiber direction)

Answer 6

Action:
1- Compression of the abdominal contents

Question 7

• 90. Internal Obliques

TG pg. 211

> Name the Action(s) of this muscle.

(Note: See diagrams for fiber direction)

Answer 7

Action:
1- Compression of the abdominal contents
2- Flexion of the torso at the waist (bilaterally)
3- Lateral flexion of the torso at the waist (unilaterally)
4- Rotation of the torso at the waist (unilaterally)

Question 8

91. External Obliques

TG pg. 209-212

> Name the Action(s) of this muscle.

(Note: See diagrams for fiber direction)

Answer 8

Action:
1- Compression of the abdominal contents
2- Flexion of the torso at the waist (bilaterally)
3- Lateral flexion of the torso at the waist (unilaterally)
4- Rotation of the torso at the waist (unilaterally)

Question 9

68. Quadratus Lumborum*
    “QL”

TG pg. 207-208

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

(Note: “Hip Hiker” muscle. Also, “Waddle walk” could be a sign of QL issues)

Answer 9

Origin:
1- Iliac crest

Insertion:
1- 12th rib
2- Transverse processes of the lumbar vertebrae

Action:
1- Extension of the torso at the waist (bilaterally)
2- Lateral flexion of the torso at the waist (unilaterally)