Muscles of the Upper Body & Core

Question 1

What muscle flexes the trunk & aids in expiration?

Answer 1

Rectus Abdominus

The rectus abdominis is a pair of long, flat muscles located on either side of the midline of the abdomen, running from the lower ribs to the pubic bone, and are primarily responsible for flexing the spine, creating the visible “six-pack” appearance when well-defined; they also help maintain abdominal pressure and stabilize the body during movement by holding internal organs in place

Question 2

What muscle stabilizes spine and hips before movement?

Answer 2

Transversus Abdominis

Question 3

This muscle flexes the trunk to the sides and rotates torso

Answer 3

Obliques

Obliques also help with protection of organs. There are two types of obliques; internal & external.

Internal obliques rotate ipsilateral (same side)

External obliques rotate contralateral (opposite side)

Question 4

This muscle extends the lumbar spine and allows ipsilateral flexation to the sides.

Answer 4

Quadratus Lumborum

This muscle is one of the more commonly injured muscles. This happens when surrounding muscles such as the glutes or rectus abdominus are weak and put excess load on the muscle. Known as the Q.L.

Question 5

These muscles extend the vertebral column and cause ipsilateral flexation of the vertebral column

Answer 5

Erector Spinae

There are three muscles in this grouping.
• Iliocostalis
• Longissimus
• Spinalis
These muscles are also known to be the first line of protection for the spine.

Question 6

What causes the extension, adduction, internal rotation, and horizontal abduction at the shoulder?

Answer 6

Latissimus Dorsi “Lats”

Latissimus Dorsi is latin for the widest back. It is the muscle best for having a wide back

Question 7

This muscle retracts and elevates the scapula

Answer 7

Trapezius “Traps”

This kite shaped muscle connects up the neck and is a major cause of many headaches due to looking down for prolonged periods

Question 8

What muscles retract, rotate, and stabilize the scapula?

Answer 8

Rhomboid Minor & Rhomboid Major

They are found deep to the traps

Question 9

This muscle elevates the scapula and supports scapula rotation as you reach up

Answer 9

Levator Scapula

When your neck is stiff this muscle is typically to blame

Question 10

What muscle protracts the scapula?

Answer 10

Serratus Anterior

Also stabilizes the scapula

Question 11

What muscle adducts, medially rotates, flexes, & extends the humerus?

Answer 11

Pectoralis Major “Pecs”

This is the main upper body pushing mechanism. Superficial to the pectoralis minor

Question 12

These muscles abduct, flex, & extend the shoulders

Answer 12

Deltoids

There are three heads to the deltoid
• Anterior (frontal)
• Lateral (middle)
• Posterior (rear)

The posterior deltoid is one of the most difficult muscles to grow

Question 13

This muscle internally rotates the humerus

Answer 13

Teres Major

This muscle assists the lats (synergist). It is not a part of the rotator cuff

Question 14

What muscle rotates the shoulder?

Answer 14

The Rotator Cuff

Rotator cuff injuries are often & problematic. There are four muscles to the rotator cuff
• Supraspinatus
• Infraspinatus
• Teres Minor
• Subscapularis “S.I.T.S.”

Question 15

What muscle flexes the elbow and supinates the forearm?

Answer 15

Biceps Brachii

There are two heads to a bicep.
The short head (caput breve) and long head (caput longum)

Question 16

This muscle flexes the elbow

Answer 16

Brachialis

This muscle is deeper than the bicep. It connects past the elbow into the forearm