WJEC GCSE in Physical Education Biomechanics Movement analysis

WJEC GCSE in Physical Education Biomechanics: Movement analysis

Background • This Power. Point resource covers four biomechanics topics for the WJEC GCSE in Physical Education. • It relates to the third key area – Movement analysis.

Content • This topic ‘Movement analysis’ includes the following content. – Muscular contractions – Lever system – Planes and axes of movement – Sports technology • There is also a Task section at the end containing questions and answers related to information within this presentation.

Overview Biomechanics is often thought as the science underlying technique. Sports performers and coaches use biomechanical analysis to help improve performance, technically and tactically, as well as to help understand how and why the body moves the way it does.

Muscular contractions

Muscular contractions Muscles contract across joints to cause movement. Muscles work in pairs and when one muscle contracts the opposite muscle relaxes (antagonistic muscle action).

Muscular contractions Muscles contract in different ways to produce movement. • Isotonic contraction: the muscle producing the tension controls the speed of contraction. – Concentric contraction – shortening of muscle. – Eccentric contraction – lengthening of muscle. • Isometric contraction: the muscle producing the tension but staying the same length.

Lever system

Levers • Knowledge of levers develops an understanding of how the body moves and explains the interaction of the skeletal system to create movement. • Levers allow us to create movement that is greater than the force applied.

Components of a lever system Levers are made up of the following three components. • Fulcrum (pivot): the point at which the lever rotates (pivots) around. • Effort (force): the location where the force (effort) is applied. • Load (resistance): the location of the load/weight that is being moved/lifted. There are three classifications of lever. • Class 1 lever. • Class 2 lever. • Class 3 lever.

Class 1 lever Load Fulcrum Load Effort Fulcrum Examples: • Neck extension. • Heading a ball. • Rowing. Effort Load

Class 2 lever Load Fulcrum Effort Examples: • Standing heel lift. • Ankle plantarflexion, e. g. marking in netball. Effort Fulcrum Load

Class 3 lever Effort Load Fulcrum This is the lever most commonly used in sport and movement. Effort Load Examples: • Bicep curl. • Knee flexion, e. g. kicking. Fulcrum

Joints and articulations Knowledge of the skeletal system and how it works helps us to understand movement and explain how skills are performed. Knowledge of the possible movements at each joint can help coaches to understand skill development and performance improvement. Tennis elbow

Joints Skeletal joints are classified according to their structural and functional (range and type of movement) characteristics. There are three structural classifications of joints: • fixed (fibrous) • cartilaginous • synovial.

Synovial joints The characteristics of synovial joints are: • the most common joint in the human skeletal system • have a joint cavity • articulating bones held together by ligaments • highly moveable. Examples: • Shoulder. • Knee.

Structure of synovial joints Synovial joints are made up of the following. • Synovial cavity – a fluid-filled space that separates the articulating bones. • Synovial fluid – fluid that lubricates the joint and nourishes the articular cartilage. • Articular cartilage – hyaline cartilage covers the articulating surfaces, reduces friction and acts as a shock absorber. • Ligaments – connect bone to bone and stabilise the joint. • Tendons – connect bone to muscle and enable movement.

hinge gliding pivot Types of synovial joint ball and socket saddle condyloid The ‘hinge’ and ‘ball and socket’ joints are the most commonly used in sport, e. g. shoulder and knee.

Hinge joint • A hinge joint is uni-axial (like a door hinge) – flexion and extension. • It allows movement in one plane. Examples: • Ulno-humeral. • Inter-phalangeal.

Ball and socket joint • A ball and socket joint is tri-axial. • It allows movement in three planes, e. g. flexion/extension, abduction/adduction, rotation. • It is the most mobile type of joint. Examples: • Hip. • Shoulder.

Planes and axes of movement

Planes and axes of movement Why is it important to be able to describe movement? • Understand technique. • Develop ideal technical model of performance. • Understand injury mechanisms. • Understand the movements that contribute to successful performance. • Communication of technique: coach–performer.

Planes of movement Plane: a flat surface; any two points on the plane can be joined with a straight line without intersecting the plane. Plane of motion: there are three imaginary anatomical planes that intersect at the body’s centre of gravity dividing the body into equal portions.

Anatomical planes of motion Sagittal plane Frontal plane Transverse (horizontal) plane

Frontal plane An imaginary vertical plane that divides the body into equal front and back (anterior and posterior) portions. Example: • Cartwheel. Frontal plane

Sagittal plane An imaginary vertical plane that divides the body into equal left and right portions. Example: • Back flip. Sagittal plane

Horizontal/transverse plane An imaginary horizontal plane that divides the body into equal upper and lower portions. Example: • Discus throw. Horizontal plane

Planes of motion Most movements in sport occur in multiple planes. However some movements are more planar (in one plane) than others. When movement is in one plane it means that no part of the body crosses from one side of the plane to the other during the movement.

Axes of motion • There are three imaginary anatomical axes that intersect at the Longitudinal axis body’s centre of gravity. • Motion happens around these axes. • In most sporting actions, movement is about Transverse axis more than one axis. Frontal axis

Longitudinal axis An imaginary pole that runs vertically through the body from top to bottom and is perpendicular to the ground. Example: • Full twist.

Transverse axis An imaginary pole that runs horizontally through the body from side to side (laterally). Example: • Somersault.

Frontal axis An imaginary pole that runs horizontally through the body from front to back. Example: • Cartwheel.

Movement patterns In order to understand sporting performance we need to be able to describe the movement of the human body. Using the planes and axes of movement and joint actions we can describe performance and understand the way people move.

Flexion/extension Flexion and extension happen in the sagittal plane. • Flexion: the ‘closing’ of a joint. • Extension: the ‘opening’ of a joint. Flexion Extension

Abduction/adduction Abduction and adduction involve moving limbs away from and towards the midline of the body in the frontal plane. • Abduction: moving limbs away from the body. • Adduction: moving limbs towards the body. Adduction Abduction

Circumduction describes circular motion and is a combination of flexion, extension, abduction and adduction.

Rotation describes ‘twisting’ movement in the transverse plane, usually about the longitudinal axis.

Sports technology

Sports technology Technology affects almost every aspect of sport from performance on and off the field to spectating and public profile. Increasingly advances in technology influence grass roots sport as well as elite sport.

Technological developments Technology applied to physical activity has played an important role both in training and competition. This is evident in a variety of ways including the creation of new sports facilities, the equipment used, officiating, spectating, coaching and performing (analysis and training). Materials technology Clothing Equipment Materials Officiating Facilities Coaching Technological developments ICT Safety features Performance analysis Training technology

Analysis of performance There a number of methods which can be used by the coach or athlete to analyse performance which include the following. Technique • Video analysis. • Movement patterns and phases. • Technical aspects. Physical attributes • Time/motion analysis. • Distance covered. • Testing/training. Tactics • Notational analysis. • Monitoring trends in performance. • Systems. Behaviour • Psychological profiling. • Predicting behaviour. • Motivation, stress, arousal.

Tasks: Questions and answers

Task: Question 1. How would you describe this movement in terms of planes and axes of motion? Back handspring

Task: Answer 1. During a back handspring, movement is in the sagittal plane about the transverse axis. Back handspring

Task: Question 1. What is the joint action during these movements? – At the elbow during a tennis forehand. – At the knee when kicking a football.

Task: Answer 1. The joint action at the elbow during a tennis forehand = Flexion. The joint action at the knee when kicking a football = Extension.

Task: Questions What is the movement in the following skills? 1. Cricket bowling. – What plane is the movement mainly in? – What is the joint action at the shoulder? 2. Hammer throw. – What plane is the movement mainly in? – Around what axis is the performer rotating? 3. Bicep curl. – What is the joint action at the elbow?

Task: Answers 1. Cricket bowling. – Movement is mostly in the frontal plane. – The joint action at the shoulder is circumduction. 2. Hammer throw. – Movement is mostly in the transverse plane. – The performer is rotating about their longitudinal axis. 3. Bicep curl. – The joint action at the elbow is flexion.

Task: Question 1. What classification of lever is an elbow?

Task: Answer 1. An elbow is a Class 3 type lever. This is the most commonly used lever in sport and movement.