The document discusses the fundamentals of the muscular system, including: - The 3 types of muscle: skeletal, smooth, and cardiac - The 3 main functions of skeletal muscle: movement, posture, and heat production - Key terms like origin, insertion, prime mover, synergists, and antagonists - The differences between isotonic and isometric contractions - Common muscles of the torso, shoulders, hips, and legs that yoga teachers should be familiar with

1. The Muscular System
Yoga Teacher Training

2. Skeletal System Quiz

3. Muscular System Fundamentals
• 3 Types of Muscle:
– Skeletal/ Voluntary muscle: attach to bone, responsible for
voluntary movement, composed of muscle fibers bundled
together
– Smooth/ Involuntary muscle: important part of blood vessel
walls and hollow organs (ex. Bladder, intestines & viscera)
– Cardiac Muscle
• 3 Functions of Skeletal Muscle:
• 1. Movement
• 2. Posture
• 3. Heat Production

4. • Muscle fibers only contract in one
direction.
• Most skeletal muscles attach to 2 bones
with a moveable joint between them.
• Tendons attach muscle to bone.
• The muscle’s attachment to the more
stationary bone is called the origin.
• The muscle’s attachment to the more
moveable bone is called the insertion.
• Knowing the origin & insertion help you
determine the purpose and direction of
movement of a particular muscle.
• The Bursa is a small fluid filled sac that lies
between some tendons and the bones
beneath them making it easier for the
tendon to slide over a bone.
• The Bursa is made from connective tissue
and lined with a synovial membrane that
secretes lubricating synovial fluid.

5. Movement: Muscles pull bones
• Because the length of a skeletal muscle shortens as it’s fibers contract, the
bones to which the muscle attaches move closer together.
• As a rule, only the insertion bone moves (there are exceptions to every
rule). A muscle’s insertion bone moves toward it’s origin bone.
• Muscles work in coordinated groups.
• Prime Mover: the muscle primarily responsible for movement within a
muscle group.
• Synergists: the other muscles that assist in producing a movement
• Antagonists: opposing muscles that relax as the prime mover & synergists
contract. When the antagonists contract they produce a movement
opposite that of the prime mover. Ex. Biceps & Triceps

6. Fatigue & Oxygen Debt
• Fatigue: Loss of muscle power/weakness; when muscle cells are
stimulated repeatedly without adequate rest then the strength of the
contraction decreases. If this continues eventually the muscle loses it’s
ability to contract
• Muscular movement is fueled by the breakdown of ATP stored in muscle
cells. Formation of ATP requires oxygen.
• When oxygen supplies run low the body converts to anaerobic energy
production (doesn’t require oxygen). This results in a build up of Lactic
Acid. (lactic acid causes soreness and pain)
• Oxygen Debt describes the continued increased metabolism that must
occur to remove excess lactic acid and replace depleted energy reserves
(ATP). Hence the labored breathing after strenuous exercise. This is why
we breath deep throughout yoga.

7. Types of Muscle Contractions
• Each muscle fiber contracts completely
when stimulated. However every
muscle is composed of many muscle
fibers, each one with a different
threshold stimulus. (threshold stimulus
is the minimal level of stimulation
required to cause a fiber to contract).
This is how we control the strength of
muscular contraction required for
specific movements.
• Isotonic Contraction: produces
movement at a joint; the muscle
shortens and the insertion moves
toward the origin.
• Repeated Isotonic contractions
increase endurance.
• Isometric Contraction: the muscle does
not shorten and no movement ocurs
but tension is increased within the
muscle.
• Repeated isometric contractions make
a muscle grow larger and stronger.

8. Common Muscles You Should Know
Pectoralis Major Pectoralis Minor

9. Biceps Triceps

11. Muscles of the Rotator Cuff
Supraspinatus Infraspinatus

12. Teres Minor Subscapularis

13. Deltoid Trapezius

14. Latissimus Dorsi Rhomboids

16. Muscles of the core
External Obliques Internal Obliques

17. Transverse Abdominis Rectus Abdominis

18. Pelvic Floor

19. Illiopsoas
Psoas Illiacus

20. Muscles of the Hips & Legs
Pirifomis Gluteus Maximus

23. I.T. Band & T.F.L. Adductors

24. Gastrocnemius Soleus

25. Diaphram