Transcript Lesson 2 - Muscular Isotonic

Year 11 GCSE PE
A healthy, active lifestyle and your
muscular system
Starter
Label the diagram provided with the
muscles learnt last lesson.
Learning Objectives
C - I can explain the difference between
isometric and isotonic muscle contractions?
B- I can describe and apply different
movements at joints
A/A* I can apply muscles and movement
and explain it in a sporting situation?
Movements at joints…
Flexion - The bending of a joint so that
the bones forming the joint are brought
closer together.
Extension - The
straightening of a joint so
that the bones forming
the joint are moved
farther apart
Movements at joints…
Abduction - to move away from the
midline plane of the body
Adduction – to bring back
towards the midline plane
of the body
Muscle action table
MUSCLE
MUSCLE ACTION
SPORTING ACTION
Triceps
Extends lower arm at
the elbow
Volleyball player has
arms outstretched to
block the ball
Biceps
Flexes arm at the
elbow
Tennis serve – racket
preparation, when
racket is behind head
Deltoids
Abducts upper arm at
the shoulder
Preparation for a
cartwheel in
gymnastics
Pectorals
Adduction of upper
arm at the shoulder
Arm action in front
crawl (pull)
Trapezius
Adducts and rotates
the scapula, rotation
of head at atlas and
axis
Lifting of the head to
watch the flight of the
shuttle in badminton.
Back crawl swimming
action
Gluteals
Extends the leg at the hip
Running action, one leg is
left stretched back
behind the other
Quadriceps
Extends the leg at the knee
Follow through after kicking
a ball in football
Hamstring
Flexes the leg at the knee
Tacking the leg back in
preparation to strike a
ball in a drop goal
attempt in rugby
gastrocnemius
Plantar flexion of the foot
(pointing your toes)
Going up onto toes prior to
take off in a diving
competition
Latissimus dorsi
Adducts and rotates the
humerus at the shoulder
(draws the arm back
and towards the body)
Pulling the arm back in
archery
Abdominals
Flex, rotate and laterally
bend trunk
Forward action in
sit-ups
Task
• In your pairs, discuss the sporting example
provided on the picture
- What joint is the movement
occurring at?
- What movement has occurred at the
joint?
- Which muscle is contracting?
- Which muscle is relaxing?
Types of Muscle Contractions
There are two types of muscle
contractions you need to know about:
1). Isometric contractions
2). Isotonic Contractions (of which
there are two types)
Muscle Contraction (Isometric)
• Muscles contract in 3 ways
• When muscles are working but stay
the same length this is called
isometric contraction. There is no
movement

The arms can now work effectively
to complete the exercise
Muscle Contraction (Isotonic)
• In Isotonic contractions our muscles
create movement as they contract
• There are two types of Isotonic
contraction
• When a muscle shortens as it
contracts this is called a concentric
contraction
• An example of this would be the
bicep when lifting the weight while
doing a ‘curl’
• When a muscle lengthens while still
being tense this is called an eccentric
contraction
• This happens as you lower the weight
under control while doing a curl
Homework
Complete the exam questions.
Due in Thursday 8th May.
Plenary
• One partner to perform a movement with a
body part – the other partner to identify the
muscle contracting