PE Unit 1 AOS 1

Ligaments connect?

Ligaments connect?

bone to bone

tendons connect?

Muscles to bones

Cartilage is

a protective shock absorbing gel between joints

Superior

Closer to the head

Inferior

Closer to the feet

Anterior

Towards the front of the body

Posterior

Towards the back of the body

Distal

Further away from the point of attachment

Superficial

Closer to the surface of the body

Deep

Internal or further from the surface

Palmar

The palm side of the hand

Plantar

The sole side of the foot

2 Sections of the body

Axial and Appendicular

Axial Section is…

the main supporting bones for the body and includes the skull, vertebral column and rib cage

Appendicular section

Made up of the limb bones and their girdles which connect onto the axial section

The Vertical Column is made of

• The cervical vertebrate

• The thoracic vertebrate

• The lumbar vertebrate

• The sacrum

  • The coccyx

Joints

Occur when two or more bones meet

Joints catergories

• Fixed or Fibrous

• Cartilaginous

• Synovial

Fixed or fibrous joints

Have a strong connection between bones, allowing no movement eg. skull, pelvis

Cartilaginous joints

These bones are connected by cartilage allowing for slight movement eg, ribs attaching to sternum, lumbar vertebrate

Synovial joints

These joints have cavities filled with synovial fluid allowing for free movement eg. hip and knee joints

6 types of synovial joints

• Pivot

• Gliding

• Condyloid

• Saddle

• Hinge

• Ball and socket

Pivot joint

A uniaxial joint that only allows rotation, eg radioulnar joint

Gliding Joint

Occurs when flat bones glide past each other, usually in a biaxial manner, eg carpals/tarsals

Ball and socket joint

occurs where a rounded bone head articulates with a cup shaped cavity, eg shoulder, hip

Hinge joint

A uniaxial joint used for extension and flexion, eg, knee and elbow

Saddle joint

Occurs where concave and convex bone surfaces align, generally biaxial, eg carpometacarpal joint of thumb

Condyloid joint

Very similar to a hinge joint but allows a slight rotation so is biaxial eg, wrist

Joint movement - Flexion

Bending movement

Joint movement - Extension

Straightening movement

Joint movement - Abduction

Movement away from the body

Joint movement - Adduction

Movement towards the body

Joint movement - Rotation

When a bone turns on its own axis within a joint

Joint movement - Circumduction

Movement in a circular fashion

Joint movement - Supination

Turning the palm facing up

Joint movement - Pronation

Turning the palm facing down

Joint movement - Dorsiflexion

Toes are pointing up

Joint movement - Plantarflexion

Toes are pointing down

Joint movement - Inversion

When the sole of the foot is turned inwards

Eversion

When the sole of the foot is turned outwards

3 types of muscles

• Skeletal muscle

• Smooth muscle

• Cardiac muscle

Skeletal muscles

External muscles that are attached to bones and are voluntary muscles controlled by us

Smooth muscles

These are found in blood vessels and the walls of the intestine and are involuntary muscles

Cardiac muscle

These make up the wall of the heart and are involuntary muscles

Agonist

This is the muscle primarily responsible for producing movement

Antagonist

This is the muscle that relaxes as the agonist contracts to allow ease of movement and reduce injury risk

Reciprocal Inhibition

A term used to explain how muscles work in teams to allow efficient movements to occur. It describes how one muscle contracts and its opposite relaxes to allow ease of movement and reduce the risk of muscle tears

Stabilisers

These are muscles that are involved in contractions by holding or stabilising a body part, making it immobile while another body part is moving

Origin Point

The site where a muscle is attached to which the muscle can pull against

Insertion Point

The insertion occurs where the muscle attaches to a bone that is pulled by the action of the muscle

Muscle fibre bundles

Fascicles

5 Muscle shapes

• Circular

• Convergent

• Parallel

• Pennate

• Fusiform

Fibre arrangement - circular

The fascicular pattern is circular, with fibres arranged in rings, eg muscles around the eyes and mouth

Fibre arrangement - Convergent

This muscle has a broad origin and its fascicles converge towards a single tendon of insertion, eg pectoralis major muscle

Fibre arrangement - Parallel

The length of the fascicles runs parallel to the long axis of the muscle, eg sartorius, abdominal muscles

Fibre arrangement - Fusiform

These are sometimes included in the parallel group but have a wider muscle body than the point of insertion and origin, eg biceps brachii

Fibre arrangement - Pennate

These fibres are short and attach obliquely to a central tendon or tendons that run the length of the muscle

3 types of pennate muscles

• Unipennate

• Bipennate

• Multipennate

Pennate muscle - Unipennate

fascicles insert only into one side of the tendon, eg semimembranosus of the leg

Pennate muscles - Bipennate

Fascicles insert into the tendon from opposite sides so the muscle grain resembles a feather, eg rectus femoris of the quads

Pennate muscles - Multipennate

Looks like many feather side by side, eg deltoid muscle

Speed vs Power in muscle fibres

The greater the number of muscle fibres (eg in pennate muscles) the more powerful they are. The longer the muscle fibre (eg parallel and fusiform) the greater the speed

How does the brain send messages to motor neurons

through motor neurons

What is the muscle belly consisting of

Thousands of muscle fibres called fascicles

What makes up fascicles

Lots of muscles fibres surrounded by the Endomysium

What makes up muscle fibres

Lots of myofibrils surrounded by the Perimysium

What makes up myofibrils

Lots of sarcomeres

What are sarcomeres made of

Myosin and Actin

What does the I-band contain?

Only the thin actin filament

What does the A band contain

The crossover of the actin and myosin

What does the H zone contain

Only the thick myosin filament

What is the Z line

The zig-zagging line that separates sarcomeres on a myofibril

Open kinetic chains

These are exercises that allow your limb to move freely eg leg curls and triceps extensions

Closed kinetic chains

These are exercises involving the movement of multiple joints and are weight bearing. They require contact to the ground eg, squats, pushups

What do sensory neurons do

They receive information from the sense receptors and carry this to the brain

What do motor neurons do

They carry impulses from the brain and central nervous system to the muscle and bring about movement

What is a motor unit

The motor neuron and the muscle fibres it stimulates

How do nerves connect to muscles?

They connect to muscles at synapses on the individual myofibrils. The motor neuron gets really close to the myofibrils and release acetylcholine that travels across the synapse. This is repeated rapidly and it stimulates the muscle to move

All or nothing principle - All

When the electrical impulse reaches a certain threshold, all of the fibres of that motor unit will contract at the same time and as forcefully as possible.

All or nothing principle - Nothing

When the electrical impulses don’t reach the threshold, none of the fibres will contract

Muscle fibre recruitment

The nervous system controls muscle forces by varying the number of active motor units it stimulates. Recruitment is the term used to describe the number of active motor units stimulated by the brain.

Fine motor skills - motor units required

Little motor units firing

Gross motor skills - motor units required

A lot of motor units firing

Sliding filament theory

This is a theory of how muscles contract and it involves the myofilaments of actin and myosin, sliding across each other

How does sliding filament theory work

When the muscle wants to contract, the myosin filaments grab onto the actin filaments and slide it closer together. ATP then comes to the myosin head and makes it release the actin filament and this then repeats

3 Muscle Action types

• Isometric

• Isokinetic

• Isoinertial

  • Concentric

  • Eccentric

Isometric actions

Tension is produced but no joint movement or action takes place eg, pushing against a wall

Isokinetic actions

The speed or velocity is held constant

Isoinertial actions

Maintain a contant mass/inertia

Concentric actions

Involves a muscle shortens during an effort, eg, bicep flexion

Eccentric actions

Involves the muscle lengthening during an effort. This occurs in gravity resisting movement, eg bicep extension

2 Muscle fibre types

• Slow twitch fibres

• Fast twitch fibres

  • Type A

  • Type B

Slow twitch fibres

These fibres contract slowly and are able to perform over extended periods of time, producing low forces

Fast twitch fibres

These fibres produce larger force but tire more rapidly

Why do we want to prevent musculoskeletal injuries and illness?

Reduce the strain on the healthcare system and allow participants to benefit from a lifetime of enjoyment of their sporting pursuits

2 types of sport injury classification

• Acute injuries

  • Direct

  • Indirect

• Chronic injuries

Acute injuries

These happen suddenly and usually without warning

Chronic injuries

These are associated with overuse of a particular area of the body over a period of time

Acute direct injury

These are sudden injuries resulting from an external force like a collision with someone or a direct blow from an implement

Indirect acute injuries

These are sudden injuries usually caused by a sudden change in direction or intensity