MUSCULAR SYSTEM

MUSCULAR SYSTEM - UPPER BODY POSTERIOR VIEW

Teres Major

Trapezius- Upper back

Latisimus Dorsi- Lower Back

Erector spinae

MUSCULAR SYSTEM - UPPER BODY ANTERIOR VIEW

Biceps

Triceps

Deltoids

Pectoralis Major

Rectus AbdominusObliques

MUSCULAR SYSTEM - LOWER BODY : ANTERIOR VIEW

Quadriceps:

• Rectus femoris

• Vastus intermedius

• Vastus Lateralis

• Vastus Medialis  • Tibialis anterior

MUSCULAR SYSTEM LOWER BODY : POSTERIOR VIEW

Gluteus Maximus

Hamstrings:

• Biceps Femoris

• Semitendinosus

• Semimembranosus

Soleus

Gastrocnemius

HOW ARE MUSCLES ATTACHED TO BONE?

ORIGIN - ATTACHMENT TO A MOVABLE BONE

INSERTION - ATTACHMENT TO AN IMMOVABLE BONE

MUSCLES ARE ALWAYS ATTACHED TO AT LEAST 2 POINTS

MOVEMENT IS ATTAINED DUE TO A MUSCLE MOVING AN ATTACHED BONE

MUSCLE ATTACHMENTS

Origin

Insertion

MUSCLES

MUSCLES UNDERPIN HUMAN MOVEMENT IN ALL MANNERS FROM PICKING UP A PEN TO STRIKING A BALL.

AN ATHLETES ABILITY TO MOVE MUSCLE EFFICIENTLY AND EFFECTIVELY IN UNISON CAN OFTEN BE THE DIFFERENCE BETWEEN WINNING AND LOSING

TYPES OF SKELETAL MUSCLE

WITHIN OUR SKELETAL MUSCLE WE ACTUALLY HAVE 2 TYPES OF MUSCLE FIBRE CALLED

FAST AND SLOW TWITCH FIBRES, RELATED TO THE SPEED IN WHICH THEY CONTRACT.

Slow Fibres: Walk long distances

Fast fibres: React quickly when needed

RED in colour, as they have a good blood supply

They are suited to endurance work and are slow to fatigue - Due to having a dense network of blood vessels.

TYPE 1 – SLOW TWITCH FIBRES

They also contain many MITOCHONDRIA (Energy producing organelles within cells), making them more efficient at producing energy using OXYGEN (O2).

Type 1 – Slow Twitch Fibres

FAST TWITCH FIBRES CONTRACT TWICE AS QUICKLY AS SLOW TWITCH

FIBRES AND THICKER IN SIZE.

They have a poor blood supply, meaning they are whiter in appearance and will fatigue quicker due to lack of OXYGEN (O2)

Type 2a and type 2b – Fast Twitch Fibres

Their FASTER, HARDER contractions make them suitable for producing fast and powerful contractions. E.G: Sprinting and Weightlifting

Type 2a and type 2b – Fast Twitch Fibres

TYPE 2 (A)

Work at slightly lower intensities, but higher than slow twitch fibres are capable of. For example, a 400m runner would utilise Type 2a fibres.

Type 2 (b)These fibres work when a person is working close to their maximum intensity. For example, a 100m runner would use these type of fibres, or an Olympic lifter performing a fast lift.

MUSCLE FIBRE TYPES

CAN YOU CHANGE FROM ONE TO THE OTHER WITH TRAINING?

TRAINING EFFECTS FOR MUSCLE FIBRES…

Type 1 and Type 2b fibres will always retain their distinctive features. However, Type 2a can take on characteristics of Type 1 and Type 2b depending on the training (they do not change their fibre type).

Bursztyn (1997): well trained middle- distance athletes will have 80% slow twitch fibres and well trained sprinters may have up to 75% fast twitch

fibres

How do muscles work? Muscles can only pull

Muscles are attached to bones by tendons

Muscles pull when they contract

When the muscle contracts it pulls on the bone causing movement

How do muscles work?

• The bone act like levers and the joints are the fulcrum

• Muscles get shorter and fatter when they contract.

• Muscles usually work as pairs pulling in opposite directions – these are called antagonistic muscles.

The biceps and triceps work together as an antagonistic pair to move the elbow joint.

To flex the elbow, the biceps (the flexor) contracts and the triceps (the extensor) relaxes.

To extend the elbow, the actions are reversed so that the triceps contracts and the biceps relaxes.

The muscles of the upper arm

The quadriceps and hamstrings in the legs are another antagonistic pair. Can you answer the following questions?

Which joint do they move?

What types of movement are produced?

Which is the flexor and which is the extensor?

Identify the origin and insertion of each muscle.

quadriceps

hamstrings

Quad & Hamstring movement

SYNERGISTS AND FIXATORS SYNERGISTS AND FIXATORS ARE MUSCLES THAT HELP THE ANTAGONIST PAIR PRODUCE A MORE EFFICIENT MOVEMENT

A SYNERGIST MAY COUNTERACT AN UNWANTED MOVEMENT IN THE AGONIST

A FIXATOR HOLDS THE BONE STILL THAT THE AGONIST IS ATTACHED TO

SYNERGISTS AND FIXATORS

DURING ELBOW FLEXION AND EXTENSION THE SHOULDER MUSCLES HOLD THE SCAPULA (SHOULDER BLADE) STILL (BOTH THE BICEPS AND TRICEPS ATTACH TO THE SCAPULA).

The fixators hold the scapula still by increasing tension, but keeping the same length. In the same way that a guy rope holds a tent up.

WHAT IS MUSCLE MEMORY?"MUSCLE MEMORY" DESCRIBES THE

PHENOMENON OF SKELETAL MUSCLE ACTIVITY THAT IS LEARNED BECOMES ESSENTIALLY AUTOMATIC WITH PRACTICE.

E.g. Walking is automatic takes no real cognitive effort learned & needs concentration for toddlers.

With constant practice:1. Neural networks & motor neuron/muscle pathways

become fast and effortless,2. No conscious thought to achieve the fluid sequence

of motor activity that produces optimal walking behaviour.

Eccentric - Involves controlling the weight on it’s way down

Concentric - Contraction to push weight away from the body

ECCENTRIC AND CONCENTRIC CONTRACTIONS

ISOMETRIC CONTRACTION

WHERE A MUSCLE CONTRACTS, BUT DOES NOT CHANGE IN LENGTH.

THE MUSCLE IS ACTIVE IN HOLDING A STATIC POSITION

THIS IS EASY TO TRAIN, BUT SOON LEADS TO FATIGUE

Give examples of sporting activities using each of the types of contraction

Muscle contraction