PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION KEY WORDS IN PDHPE DESCRIBE Provide characteristics and features IDENTIFY Recognise and name DISCUSS Means to present the pros and cons of an issue. A discussion presents arguments for and or against an issue. DEFINE State meaning and identify (recognise and name) essential qualities. EXPLAIN Relate cause and effect; make the relationships between things evident; provide why and/or how. EVALUATE Make a judgement based on criteria; determine the value of JUSTIFY Means to defend a point of view or conclusion. It is about giving examples to support your viewpoint. Firstly, you must take a side or make a conclusion. Secondly, you provide factual evidence to demonstrate why your viewpoint is correct. You are attempting to defend the stance that you have taken. Superior background knowledge of subject content is vital for a good justification. The more ideas you can put forward to support your view, the better your answer will be. However, more general discussion or description about the concept won’t be enough. The statements you make must all work toward defending your viewpoint, not just describing what it is. You must say why your viewpoint is correct. OUTLINE Sketch in general terms; indicate the main features of PROPOSE Put forward (for example a point of view, idea, argument or suggestion) for consideration or action Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION CRITICAL QUESTION 1 Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION ANATOMICAL POSITION AND TERMS Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION NAME DIAGRAM DESCRIPTION Anatomical position Stand upright, arms by side, palms facing forward and looking straight ahead Superior Towards the head or above (of where you are looking) Inferior Towards the feet or below (of where you are looking) Anterior Front or in front of (where you are looking) Posterior (p after a, behind a in alphabet) Back of at the back of (where you are looking) Medial Towards the midline of the body Lateral Away from midline of the body Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Proximal Closer to the top of a limb Distal Closer towards the bottom or end of a limb Supine Lying face upwards Prone Lying face downwards PLANES OF THE BODY Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION MUSCULOSKELETAL AND CARDIORESPIRATORY SYSTEM Students learn about • Skeletal system – major bones involved in movement – structure and function of synovial joints – joint actions, e.g. extension and flexion Students learn to • Identify the location and type of major bones involved in movement, e.g. long bones articulate at hinge joints for flexion and extension FUNCTION OF THE SKELETAL SYSTEM Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION TYPES OF BONES Long Bones - These are long in length and elongated in shape. Femur, humerus, radius ulna Short Bones - These are cube like shapes Carpals, Metacarpals, Tarsals Flat Bones - These are flat, thin bones that usually protect organs. Skull and sternum Irregular Bones - These are bones that do not fall into one of the above categories they are usually complicated in shape. Vertebrae and pelvis. Sesamoid Bones - These are bones found in the body where tendons pass over a joint. Foot, knee, and hand Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION AXIAL SKELETON The axial skeleton provides the supportive structure of the skeleton. It is made up of the: - skull, - vertebral column, - sternum and - ribs. APPENDICULAR SKELETON The appendicular skeleton is made up of: - the upper limbs, - shoulder girdle, - lower limbs and - hip girdle. It provides the framework for movement. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION JOINTS A joint is a place where two or more bones meet. Just about every bone in the body forms at least one joint with another bone. Joints can allow movement, but they can also provide stability. There are 3 types of joints: - Fibrous (Fixed) Cartilaginous (Slightly moveable) Synovial (Freely moveable) Joints are further classified depending on - The shape of the articulating bones - The types of tissue that connect the bones together. Type of Joint Description Examples Fibrous These joints are firmly held together by a thin layer of strong connective tissue. Sutures of the skull Teeth in their sockets. There is no movement between the bones. Cartilaginous The surfaces of the bones forming the joints are attached to each other by means of discs and ligaments. The vertebrae joint between the sacrum and the hip bones These joints allow only a limited amount of movement. Synovial These joints are freely moveable. They are characterised by the presence of a closed space or cavity between the bones Types of synovial Joints - Hinge Ball and socket Condyloid Gliding Saddle Pivot Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION SYNOVIAL JOINTS Hinge Description Example Allows movement in only one direction due to the shape of the bones and the strong ligaments which prevent side to side movement Knee, elbow, ankle Bending your arm Ball and socket One bone is ball shaped and fits into a Humorous fits into shoulder socket cup shaped depression. These joints are the most freely moving of all synovial joints. Condyloid The condyloid joint is basically a hinge joint which allows some sideways movement. The dome shaped surface of one bone fits into the hollow formed by one or more other bones forming the joint. Joint between the radius and carpal bones in the wrist Gliding The gliding joint occurs where two bones with flat surfaces slide on each other but are restricted to limited movement by the ligaments. Joints between the carpals in the hand Saddle Convex and concave surfaces are placed against each other. This allows movement in two directions. One bone is shaped like a saddle, and the other is shaped like its rider. Trapeziometacarpal joint at base of thumb Pivot Only allows rotation. Joint which allows us to turn our heads from side to side Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION FEATURES OF SYNOVIAL JOINTS Performance in most sporting activities relies heavily on the stability and function of synovial joints. Their stability and functions are provided by a number of important structures. These include: Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION JOINT ACTIONS Flexion - - Is the bending of a body part or decreasing the angle between the parts. Bending your elbow Extension - Is the straightening of a body part to increase the angle between the parts. Straightening the leg at the knee Abduction - Is the moving of a part of the body AWAY from the midline. Raising the leg or arm to the side Adduction - Is the moving of a part of the body TOWARDS the midline. Lowering the arm or leg towards the midline Pronation - Is the turning of the hand so the palm faces downwards Supination - Is the turning of the hand so the palm faces upwards. Rotation - Rotation is turning the body part on the axis. Turning head from side to side Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Circumduction - - Circumduction is a combination of movement which result in a cone-like movement. Arm circles Plantar Flexion - Is the movement of the foot at the ankle The toes and foot point down. Dorsi Flexion - Is the ability to bend at the ankle, Moving the front of the foot upward. Inversion - Is turning the foot so that the sole faces inwards. Eversion - Is turning the foot so that the sole faces outwards. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LEARN TO ACTIVITY Location Bones Joint Movement Action Arms Long Bones: Hinge joint Flexion - Netball shot Legs - - Humerus Radius Ulna Long Bones AFL Kick - Femur Tibia Fibula Extension Hinge Joint Flexion Extension Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION MUSCULOSKELETAL AND CARDIORESPIRATORY SYSTEM Students learn about • Muscular system – major muscles involved in movement – – muscle relationship (agonist, antagonist) Students learn to • Identify the location of the major muscles involved in movement and related joint actions • Perform and analyse movements, e.g. overarm throw, by examining: types of muscle contraction (Concentric, eccentric, isometric) – bones involved and the joint action – muscles involved and the type of contraction MUSCULAR SYSTEM - Muscles enable us to move, breathe and communicate; provide stability so we can stand upright and serve many internal bodily functions. There are approximately 640 muscles in the body, their ability to convert energy and enable us to function is crucial to our everyday lives. MAJOR MUSCLES INVOLVED IN MOVEMENT Arms: Biceps, Triceps, Deltoid, Latissimus Dorsi, trapezius Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Legs: Hamstrings, Quadriceps, gastrocnemius, obliques TYPES OF MUSCLES CARDIAC MUSCLES - These are only found in the heart. The muscle is striated in texture but works involuntarily, so we have little control over the number of times our heart beats. SMOOTH MUSCLES - These are found in the walls of organs such as the stomach and bladder and in arteries and veins. SKELETAL MUSCLES - These are the most common types of muscle on the body. They are named because of their location: they are attached to the bones of the skeletal system. Skeletal muscles are voluntary and therefore can be controlled to contract and relax. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION ORIGIN, INSERTION AND ACTION ORIGIN - The origin of the muscle is usually attached directly or indirectly to the bone via a tendon INSERTION - The insertion of the muscle is the point of attachment at the movable end, which tends to be away from the body’s main mass. ACTION - When the muscle contracts it causes movement. This is called muscle action. Muscle Deltoid Origin Scapula Insertion Action Humerus Abduction of arm Radius Flexion of arm Clavicle Biceps Humerus Scapula Triceps Scapula Supination of forearm Ulna Extension of arm Femur Extension of thigh Humerus Gluteus Maximus Pelvis Sacrum Hamstrings Quadriceps Femur Femur Abduction of thigh Tibia Extension of thigh Fibula Flexion of leg Tibia Flexion of hip Patella Extension of leg Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION AGONIST, ANTAGOINIST AND STABILISER AGONISTS - Prime Movers the agonists muscle provides the main force that causes the desired movement. ANTAGONISTS - Muscle that reacts the muscle that opposes or reverses a particular movement. STABILISERS - Fixators the muscle that aids agonist by promoting the same movement or by reducing unnecessary movement or undesired action. TYPES OF MUSCLE CONTRACTIONS Type Description Example Photo Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Isometric contraction - - Isotonic contraction - - This is the process where the muscle contracts and no movement is produced. The length of the muscle stays the same. The Triceps and pectoral muscle when holding a starting position for a push up This is the process where the muscle contracts, producing enough force to move an object. The muscle shortens and maintains its tension throughout the whole movement. There are two types of isotonic contraction: 1. Concentric Contraction 2. Eccentric Contraction Concentric contraction - When the muscles shortens as it contracts. The pectoral muscles when completing the pushing up phase of a push up. Eccentric contraction - When the muscle lengthens as it contracts. The pectoral muscles when completing the lowering phase of the push up Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LEARN TO Movement Bones Involved Muscles and their Roles Joint Action Type of Contraction Arm Action Humerus, Ulna, radius, carpals, metacarpals Triceps, bicep, deltoid Flexion and extension Concentric and eccentric Flexion and extension Concentric and eccentric - Basketball Shot Wrist action - Netball shot Arm Action - Overarm throw Knee Action - Vertical jump Foot Action - Long jumps take off Carpal, metacarpals Scapula, humerus Pectorals, latissimus dorsi, deltoid, triceps, biceps Rotation, flexion, and extension Concentric and eccentric Femur, tibia, and fibula Quadriceps, hamstrings Flexion and extension Concentric and eccentric Tarsals, metatarsals Gastrocnemius, soleus Plantar flexion and dorsi flexion Concentric and eccentric RESPIRATORY SYSTEM Students learn about • Respiratory system – structure and function – lung function (inspiration, expiration) – exchange of gases (internal, external) Students learn to • Analyse the various aspects of lung function through participation in a range of physical activities Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION THE RESPIRATORY SYSTEM - - The respiratory system is responsible for the transfer of oxygen from the air to the blood and for the disposal of the waste product carbon dioxide. A vital element of life, the respiratory system works in conjunction with the cardiovascular system to transport oxygen and carbon dioxide around the body. While the body can do without food for a few days, the body cannot survive after a few minutes without oxygen. The availability of oxygen, its delivery to working muscles and the removal of waste products are essential for enabling repeated movements. STRUCTURE AND FUNCTION - The respiratory system is made of various structures that enable the exchange of gases both within and outside the body. Supplying all body cells with oxygen and removing carbon dioxide is the overall function of the respiratory system. Respiration in humans can be thought of in terms of external respiration & internal respiration. - External respiration refers to ventilation/breathing, i.e. gaseous exchange between an organism and its environment. Internal/cellular respiration refers to the use of oxygen & production of carbon dioxide by mitochondria in the cytoplasm of cells. It produces energy in the form of ATP MAJOR FUNCTION OF THE RESPIRATORY SYSTEM - - Providing an extensive surface area for gas exchange between air and circulating blood. Moving air to and from the exchange surfaces of the lungs along the respiratory passageways. Protecting respiratory surfaces from dehydration, temperature changes or other environmental variations and defending the respiratory system and other tissues from invasion by pathogens Producing sounds involved in speaking, singing and other forms of communication. Facilitating the detection of olfactory stimuli by olfactory receptors in the superior portions of the nasal cavity. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION INSPIRATION Air movement from the atmosphere into the lungs breathing in. The diaphragm contracts, the ribs move up and out a little which enlarges the chest cavity. Because the chest is bigger, the pressure within the lungs decreases. The air moves from an area of high pressure to low pressure, so the air is drawn into the lungs. EXPIRATION Air movement from the lungs to the atmosphere breathing out. The diaphragm and ribs return to their at-rest state which decreases the size of the chest cavity. Thus the pressure inside the lungs is now high, so air is forced out of the lungs. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION THE EXCHANGE OF GASES - - The amount and type of gases at any one place, both in the atmosphere and body, varies. Gases in the atmosphere consists mostly of oxygen and nitrogen, whereas gases in the lungs consist of carbon dioxide and water vapour. As a result of the variance in gas types, oxygen exchange occurs in the lungs because of the high levels of carbon dioxide and low levels of oxygen. EXTERNAL RESPIRATION The transfer of gas between respiratory organs such as lungs and the outer environment. - It takes place prior to internal respiration. External respiration also known as breathing refers to a process of inhaling oxygen from the air into the lungs and expelling carbon dioxide from the lungs to the air. Exchange of gases both in and out of the blood occurs simultaneously. External respiration is a physical process during which oxygen is taken up by capillaries of lung alveoli and carbon dioxide is released from blood. INTERNAL RESPIRATION The transfer of gas between the blood and cells. - Internal respiration or tissue respiration/cellular respiration refers to a metabolic process in which oxygen is released to tissues or living cells and carbon dioxide is absorbed by the blood. Once inside the cell the oxygen is used for producing energy in the form of ATP or adenosine triphosphate. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION EFFECT OF PHYSICAL ACTIVITY ON RESPIRATION - - During physical activity, the body’s higher demand for oxygen triggers a response from our respiratory system. Increased rates of breathing combine with increased volumes of air moving in and out of the lungs, to deliver more oxygen to the blood and remove wastes. At the same time, blood flow to the lungs has been increased as a result of the circulatory system’s own response to the exercise (discussed in Circulatory System). The increases in the rate (frequency) and depth (tidal volume or TV) of breathing provide greater ventilation and occur, generally, in proportion to increases in the exercise effort (workload on the body). Effect is determined by which type of exercise you are doing (anaerobic, aerobic) Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION CIRCULATORY SYSTEM Students learn about • Circulatory system – components of blood – structure and function of the heart, – arteries, veins, capillaries – pulmonary and systemic circulation – blood pressure. Students learn to • Analyse the movement of blood through the body and the influence of the circulatory and respiratory systems on movement efficiency and performance. THE CIRCULATORY SYSTEM The circulatory system, which includes the cardiovascular system, is made up of three main parts: 1. the heart 2. blood vessels 3. blood Its role is to transport materials such as nutrients, blood, hormones and waste products to muscles and organs around the body via the blood stream, and convert lactic acid into pyruvic acid. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION COMPONENTS OF BLOOD Blood plays a vital role in the body’s ability to breathe, break down nutrients for energy, eliminate waste, and maintain the body’s temperature and water balance. RED = OXYGENATED BLOOD (the brighter the shade, the more oxygen present) blood is red due to the presence of haemoglobin BLUE = DEOXYGENATED BLOOD FUCNTION OF BLOOD Function Description Distribution - of gases such as oxygen and carbon dioxide around the body transportation of waste products from cells to excretory sites transportation of hormones around the body Regulation - maintaining core body temperature maintaining normal acidity or alkaline (pH) in body tissue maintaining adequate fluid levels in the blood Protection - preventing blood loss through clot formation preventing infection through antibodies and white blood cells COMPONENTS OF BLOOD Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Component Features Plasma Plasma is a straw-coloured liquid mainly consisting of water (about 90%). Function - - White blood cells (leukocytes) It is the liquid part of blood that transports materials such as blood cells, nutrients, hormones and gases around the body. It is predominately water and contains mainly oxygen. They are formed in the bone marrow and lymph nodes. They can change shape and move against the flow of blood to the area of infection. - Platelets Tiny structures made from bone marrow cells that have no nucleus - Are the blood-clotting agencies that help stop bleeding. When we cut ourselves or break a blood vessel, platelets stick to the damaged blood vessel to block the blood flow. Red blood cells (erythrocytes) They are formed in the bone marrow and contain iron and haemoglobin. They are a flat disc shaped cell that provides a large surface area for taking up oxygen. About two million red blood cells are destroyed and replaced every second, they only live for around four months. - Are responsible for transporting oxygen and carbon dioxide around the body. They pick up oxygen from the lungs and transport it around the body to muscles, tissues and organs, where it is exchanged for carbon dioxide. They then transport the carbon dioxide back to the lungs and the exchange occurs again. - - - To provide the body with a mobile protection system against disease Responsible for fighting infection They attack and destroy germs and infections as they enter the body. When the body has an infection, the number of white blood cells increases in order to fight it. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION STRUCTURE AND FUNCTION OF THE HEART The heart is a muscular pump that contracts provide the force to keep blood circulating throughout the body. - - Slightly larger than a clanged fist and a shape of a large pear The heart lies in the chest cavity between the lungs and above the diaphragm and is protected by the ribs and sternum. Beats average 70 times per minute STRUCTURE OF HEART Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION FUNCTION OF HEART Structure Function Superior Vena Cava The large vein which returns blood to the heart from the head, neck and both upper limbs Inferior Vena Cava Returns blood to the heart from the lower part of the body Right Atrium Receives deoxygenated blood from the body through the vena cava and pumps it into the right ventricle which then sends it to the lungs to be oxygenated Right Ventricle Responsible for pumping oxygen- depleted blood to the lungs Pulmonary Artery Is the vessel transporting de-oxygenated blood from the right ventricle to the lungs Pulmonary Vein Are large blood vessels that receive oxygenated blood from the lungs and drain into the left atrium of the heart Left Atrium Plays the vital role of receiving blood from the lungs via the pulmonary veins and pumping it to the left ventricle Left Ventricle Receives oxygenated blood from the left atrium via the mitral valve and pumps it through the aorta via the aortic valve, into the systemic circulation Aorta The largest artery in the body. It arises from the left ventricle of the heart and forms and arch, then extends down to the abdomen, where it branches off into two smaller arteries Pulmonary, Mitral, Tricuspid, Aortic Valve The valves through which blood passes before leaving each chamber of the heart. The valves prevent the backward flow of blood Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION ACTION OF THE HEART The heart is able to receive blood from the veins and pump it to the lungs and the body through a rhythmic contraction and relaxation process called the cardiac cycle. The cardiac cycle consists of: Phase Description Diastole (relaxation or filling) The muscles of both the atria and ventricles relax. Blood returning from the lungs and all parts of the body flows in to fill both the atria and ventricles in preparation for systole (contraction). Systole (contraction or pumping) The atria contract first to further fill the ventricles. The ventricles then contract and push blood under pressure to the lungs and all parts of the body. As they contract, the rising pressure in the ventricles closes the atrioventricular valves (between the atrium and the ventricle) and opens the valves in the arteries leaving the heart (the aorta and the pulmonary artery). HEARTBEAT The heart is made to contract or beat regularly by small impulses of electricity that are initiated and sent out from a natural pacemaker in the wall of the right atrium. Unusual heart sounds can mean that the valves may not be working properly. Sounds Cause Low pressure By the atrioventricular valves closing - High pressure Occurs at beginning of ventricular contraction (systole) By the valves closing at the exits to the heart - Occurs after blood has been pushed from the ventricles at the end of the systole phase. Every time the heart beats, wave of blood under pressure travels through arteries, expanding and contracting arterial walls called a pulse. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION STRUCTURE AND FUNCTION OF BLOOD VESSELS For blood to flow around the body, blood is transported through blood vessels. The vessels need to be not blocked (eating healthy etc). Type of blood vessel Description Arteries These are large vessels with thick, muscular walls; they transport oxygen-rich blood away from the heart. Veins Slightly thinner walls than arteries, veins are responsible for transporting carbon dioxide (deoxygenated blood) back to the heart via the lungs. Capillaries The smallest blood vessels in the body; they have thin walls that allow the exchange of materials between blood and tissue fluid. Capillaries connect arteries to veins. Photo Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION PULMONARY AND SYSTEMIC CIRCULATION Both sides of the heart work together like two pumps with overlapping circuits. Circulation Definition Function Pulmonary circulation The flow of blood from the heart to the lungs and back to the heart. Deoxygenated blood from the body enters the right atrium via the vena cava. From here the blood flows into the right ventricle, which pumps it to the lungs via the left and right pulmonary arteries. In the lungs, carbon dioxide is released and oxygen is picked up. This process is known as pulmonary circulation. Systemic circulation The flow of blood from the heart to body tissue and back to the heart The oxygenated blood then enters the left atrium via four pulmonary veins. The blood then flows into the left ventricle. From here it is pumped up through the aorta and out to the upper and lower extremities via a number of arteries. This process is known as systemic circulation. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION HOW THE HEART PUMPS BLOOD AROUND THE BODY CIRCULATION OF BLOOD THROUGH HEART Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION BLOOD PRESSURE Blood flows through blood vessels along a pressure gradient from areas of higher pressure to areas of lower pressure. Blood pressure (BP) is the force that blood exerts on the walls of blood vessels. The flow and pressure of blood in the arteries rises with each contraction of the heart and falls when it relaxes and refills. Blood pressure has two phases — systolic and diastolic. Phase Description Systolic The highest (peak) pressure recorded when blood is forced into the arteries during contraction of the left ventricle (systole). Diastolic The minimum or lowest pressure recorded when the heart is relaxing and filling (diastole). WHAT IS BLOOD PRESSURE DETERMINED BY? Blood pressure generally reflects the quantity of blood being pushed out of the heart (cardiac output) and the ease or difficulty that blood encounters in passing through the arteries (resistance to flow). Determined by Description Cardiac output Any increase in cardiac output results in an increase in blood pressure. Volume of blood in circulation If blood volume increases because of increased water retention, such as when salt intake is high, blood pressure increases. During blood loss, such as during a haemorrhage, blood pressure falls. Resistance to blood flow Resistance to blood flow such as: - Venous return Increase of viscosity (stickiness) of blood Diameter of blood vessels As deposits build-up on walls, arteries become less elastic Since this affects cardiac output, it also affects blood pressure. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION WHAT IMPACTS BLOOD PRESSURE AND HOW IS IT MEASURED? - Blood pressure varies in response to posture (lying or standing), breathing, emotion, exercise and sleep. Temporary rises due to excitement, stress or physical exertion are quite natural and blood pressure returns to normal with rest. Under normal conditions, it provides valuable information about how well the circulatory system is operating. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION CRITICAL QUESTION 2 Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION HEALTH RELATED COMPONENTS OF PHYSICAL FITNESS Students learn about • Health-related components of physical fitness – Cardiorespiratory endurance – Muscular strength – Muscular endurance – Flexibility – Body composition Students learn to • Analyse the relationship between physical fitness and movement efficiency. Students should consider the question ‘to what degree is fitness a predictor of performance?’ WHAT ARE THEY? - Aspects of fitness that enable us to maintain our health, perform daily tasks and jobs, perform well in sporting activities and help protect us from sickness. They are the physical factors that, if we neglect them, may cause us to become unhealthy or perform poorly; for example, a gymnast with poor flexibility or a marathon runner with below-average aerobic endurance. The health-related components of physical fitness are: - cardiorespiratory endurance muscular strength muscular endurance flexibility body composition CARDIOVASCULAR ENDURANCE Fitness of heart, blood vessels and lungs (circulatory and respiratory systems) - sporting examples: swimming, cross-country, running MUSCULAR STRENGTH The force or tension a muscle or muscle group can exert against a resistance in one maximal contraction - sporting examples: weight lifting Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION MUSCULAR ENDURANCE The ability of a particular muscle group to keep working at the desired level of effort for as long as the situation demands. Often is controlled by the tolerance of the muscle group to increasing levels of lactic acid - sporting examples: muscular endurance FLEXIBILITY The body’s ability to gain the range of movement that is demanded by a particular sport or activity. Interaction between the skeletal and muscular systems - sporting examples: gymnastics, dance BODY COMPOSITION The ratio of fat-free mass to fat-mass and essentially a person’s body “shape” or somatotype - sporting examples: jockey (small), sumo- wrestler (large) MEASURING COMPONENTS OF FITNESS The measurement of physical fitness usually involves the use of laboratory or field tests to measure particular components. No one test will measure all health-related components or all skill-related components, so often a battery of tests is required for each. PURPOSE FOR TESTING There are many reasons for measuring physical fitness. They include to: - evaluate progress make comparisons with others develop accurate training programs set realistic, achievable fitness goals identify baseline and follow-up fitness levels assess individual strengths and weaknesses identify medical problems motivate to improve results Testing fitness components is a key to any training program. Providing a choice of tests is appropriate and if they are administered correctly, benefits include: - identifying strengths and weaknesses identifying any imbalances in flexibility or strength monitoring progression Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LEARN TO - TO WHAT DEGREE IS FITNESS A PREDICTOR OF PERFORMANCE? Muscular strength example: Muscular strength relates to movement efficiency because a greater strength means less “effort” is needed in order to produce particular movements and to produce a given amount of force. For example, a stronger person will find it easier to lift an 80 Kg barbell than a weaker person, even if they both can lift it. This rate of perceived effort correlated highly to fatigue, which can clearly affect performance, as technique becomes poorer. Furthermore, a stronger person can focus more on their technique in order to produce the same force or power than a weaker person. this helps in sports such as cricket, baseball, or golf, where the distance a ball is hit can have a great impact on the performance. An athlete with greater muscular strength will be able to hit the ball further, with a lower effort level and greater focus being given to technique. Body composition example: Body composition relates to movement efficiency but is generally quite specific to the sport. Generally, people with lower percentages of fat and higher percentages of muscle are able to move for longer periods of time at at greater speeds. This is partly due to the fact that they are carrying less non-movement producing weight. What I mean by this, is that the athlete is carrying as little fat as possible above and beyond what is required for their performance. This gives them a better force to mass ratio allowing them to produce faster movements or require less force to continually move themselves. This results in them saving energy over longer performances, such as marathons, or to move faster over short performances, such as 100m sprinting. However, low body fat percentage is not always advantageous. Sports such as Sumo Wrestling provide benefit to the athlete who is able to produce the most force and require more force to move. Hence why so many Sumo wrestlers are so large. This is not a matter of body fat to muscle ratio, it is simply a matter of how big can I get and still move efficiently. Other sports that benefit from simply being larger, and enabling greater overall force to be produced are sports such as shot put, discus, hammer throwing, weight lifting and even to some degree specific positions in sports, such as the front rower in rugby or the blocker in NFL. LEARN TO – RELATIONSHIP BETWEEN FITNESS AND MOVEMENT EFFICIENCY Component Definition Relationship to movement efficiency Cardiorespiratory endurance Fitness of the heart, blood vessels and lungs Having good cardiorespiratory endurance it allows body to work hard for longer and be able to maintain pace Muscular strength The force or tension a muscle or muscle group can exert against a resistance in one maximal contraction Muscular strength allows movements to be strong and powerful. Muscular strength means that all movements you do will be stronger, have more balance, stability and flexibility. Muscular strength also allows for stronger bones and muscles, meaning injuries are less likely to occur Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Muscular endurance Is the ability of a particular muscle group to keep working at the desired level of effort for as long as the situation demands. Having healthy muscular endurance allows for long periods of activity. t helps in maintaining a steady state of physical activity which in turn helps to minimize the risk of injury. Flexibility It is the body’s ability to gain the range of movement that is demanded by a particular sport or activity. Flexibility helps to prevent injury, improve posture, decrease back pain, maintain healthy joints and improve balance during movement. It is the last of these that particularly helps movement efficiency as it allows the body to perform better, with better technique while moving. Body composition The ratio of fat-free mass and essentially a person’s body “shape” or somatotype Body composition relates to movement efficiency, but is generally quite specific to the sport. Generally, people with lower percentages of fat and higher percentages of muscle are able to move for longer periods of time at at greater speeds. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION SKILL RELATED COMPONENTS OF PHYSCIAL FITNESS Students learn about • Students learn to Skill-related components of physical fitness • Measure and analyse a range of both health-related and skillrelated components of physical fitness - • Think critically about the purpose and benefits of testing physical fitness Power Speed Agility Coordination Balance Reaction time WHAT ARE THEY? The skill-related components of physical fitness are related to the performance aspect of an activity. They are the functional capacities that enable us to perform physical activities with greater skill. For example, a swimmer with a fast reaction time or a volleyball player with explosive leg power. Elite athletes will have very high levels of skill-related physical fitness compared to the levels possessed by non-elite athletes. The skill-related components of physical fitness are: POWER Muscular power is the combination of strength and speed. A powerful movement is achieved by imparting as much strength as possible, as quickly as possible. - Sporting example: jumping SPEED The ability to move the whole body or part of the body from one point to the next in the shortest possible time. - Sporting example: sprints Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION AGILITY Agility combines speed with flexibility and dynamic balance, allowing the athlete to change direction with maximal control and speed. - Sporting example: netball, tennis COORDINATION Coordination is the ability to link together a series of muscular movements, so they appear to be well controlled and efficiently executed - Sporting example: golf swing, cricket bowl BALANCE Balance is the ability of the body to remain in a state of equilibrium while performing a desired task - Sporting example: everything, gymnastics REACTION TIME Reaction time is the speed with which an individual can react to an external stimulus. Average reaction time is 0.2 seconds. It is the ability of the senses to detect a stimulus, the brain to process it and the nervous system to send the message to the muscles to respond to it. - Sporting example: sprint starts PURPOSE FOR TESTING There are many reasons for measuring physical fitness. They include to: - evaluate progress make comparisons with others develop accurate training programs set realistic, achievable fitness goals identify baseline and follow-up fitness levels assess individual strengths and weaknesses identify medical problems motivate to improve results Testing fitness components is a key to any training program. Providing a choice of tests is appropriate and if they are administered correctly, benefits include: - identifying strengths and weaknesses identifying any imbalances in flexibility or strength monitoring progression Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LEARN TO – RELATIONSHIP BETWEEN FITNESS AND MOVEMENT EFFICIENCY Component Definition Relationship to movement efficiency Power Muscular power is the combination of strength and speed. A powerful movement is achieved by imparting as much strength as possible, as quickly as possible. A powerful movement allows the body to move with less effort and more force. It allows the body to put more energy into movement and move more efficiently Speed The ability to move the whole body or part of the body from one point to the next in the shortest possible time. Speed allows the athlete to be faster, which makes them better to perform. High speed will frequently require high energy consumption. Agility Agility combines speed with flexibility and dynamic balance, allowing the athlete to change direction with maximal control and speed. Agility allows the body to be able to move in different directions. It allows the body to remain in proper alignment with good posture. Agility training can improve dynamic balance, which is the ability to maintain control of a moving centre of mass over a changing base of support. Reactivity and quickness drills can enhance natural reflexes, helping you to move faster in almost everything you do. Coordination Coordination is the ability to link together a series of muscular movements so they appear to be well controlled and efficiently executed The more coordinated a person is, the more efficient their movement will be. Coordination allows for better performance, as the individual is able to save energy with their movements and therefore can last longer at higher workloads than less coordinated people. Balance Balance is the ability of the body to remain in a state of equilibrium while performing a desired task Improved balance and muscle group coordination will naturally increase your body's ability to control itself during challenging tasks. For athletes, this means improved agility, quicker reaction times, and improved overall performance. Reaction time Reaction time is the speed with which an individual can react to an external stimulus. Average reaction time is 0.2 seconds. It is the ability of the senses to detect a stimulus, the brain to process it and the nervous system to send the message to the muscles to respond to it. Reaction time affects performance, and the better your reaction time, the better you will perform in certain situations. For example, a football player who has a faster reaction time will be able to respond faster when his opponent tries to beat him. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LEARN TO – DIFFERENT SPORTING EXAMPLES Health: Cardiorespiratory endurance Muscular strength Muscular endurance Flexibility Body Composition Skill: Power Speed Agility Coordination Balance Reaction time Surfing Flexibility is needed when surfing because the movement from lying flat onto the surfboard to standing requires a range of flexibility as well as coordination. Balance is also needed when standing on the surfboard as the water underneath the board is moving. Marathon running Cardiorespiratory endurance: improves oxygen uptake in the lungs and heart and can help a person sustain physical activity for longer. Muscular strength: Having the muscular strength and stability to absorb that force each step will minimize the load through your joints and reduce your risk of pain or injury. Weightlifting Muscular Strength and endurance is required to build their Strength to be able to hold and lift large amount of weight. Sprinting Muscular strength will ensure that you have more stability, balance, and flexibility, making injuries and falls less likely. While Building up the body power and muscle. High jump Power is required in the legs when doing high jump as the individual must be able propel themselves high enough to go over the bar. Coordination is required when doing high jump as the individual must be able to effectively run, jump and propel over the bar in a swift sequence. Body Composition is required when doing high jump AEROBIC AND ANAEROBIC TRAINING Students learn about • Aerobic and anaerobic training – FITT principle Students learn to • Design an aerobic training session based on the FITT principle • Compare the relative importance of aerobic and anaerobic training for different sports, e.g. gymnastics versus soccer Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION ENERGY SYSTEMS The three common energy-yielding processes for the replenishment and recycling of ATP (Adenosine 5'triphosphate) are the: 1. Alactacid system 2. Lactic acid system 3. Aerobic system The major difference between the systems is that the alactacid and lactic acid systems both resynthesise ATP anaerobically (without oxygen present), Whereas the aerobic system resynthesises ATP aerobically (with oxygen present). The energy system used by the body is dependent on: - How long the activity will take place The intensity of the activity How quickly the activity is performed. Creatine phosphate molecule stored in body AEROBIC TRAINING If movements are sustained and of moderate intensity, the aerobic pathway (with oxygen) supplies the bulk of energy needs. - Means with oxygen Continues for 90 seconds or more oxygen becomes available to the cells E.g. walking, marathon running, 1500-meter races To improve aerobic fitness: - Engage in long duration activities Use FITT principle to provide a beneficial training program Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION ANAEROBIC TRAINING If we perform short sharp movements as in jumping and lifting, the body uses the anaerobic pathway (oxygen is absent) to supply energy. - - Means without oxygen muscular work takes places without oxygen being present Level intensity is much higher than aerobic and effort period is much shorter Lasts for two minutes or less Our increased breathing rate delivers more oxygen to this area, but it is some time before it arrives as there is a limit to the speed of blood flow and therefore oxygen transport. o these muscles are able to use a restricted amount of stored and other fuel until oxygen becomes available. E.g. sprinting (muscles respond quickly and exhaust any fuel reserves To improve anaerobic training: - Specialised training to generate adaptations necessary for muscular work without oxygen Generally requires an aerobic foundation (swimming, sprints) but also doesn’t necessarily (diving) Work hard on specific anaerobic movements (weight lifting, jumping) Use interval training with short rests Train body’s ability to recharge and tolerate higher levels of lactic acid DIFFERENCE BETWEEN AEROBIC AND ANAEROBIC TRAINING Features Aerobic Anaerobic Goals Improved stamina, endurance, Development of force, power, lung capacity, cardiorespiratory Development of force, power, body mass and speed Warm- up General, short, low intensity exercise. Cool down essential Sustained (20 minutes or more), gradual increase in intensity, must be specific to muscles required in activity Activities Targets endurance type activities: marathon running, cycling, 1500 metre swimming, Targets explosive type activities: track events 100, 200 and 400 metre, swimming 50 Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION power walking, kayaking, triathlon together with the sustained phases of games and 100 metre, diving, weightlifting, discus, javelin, shot- put and the sprint phases in games Targeted fitness components Cardio respiratory endurance, muscular endurance, body composition Speed, power, agility Resistance training High repetition, weights with low resistance, circuits Low repetition weights, high resistance, fast plyometrics Physical benefits Improved cardiovascular system and ability to endure performance Strength, power, and speed gains, increased local muscle recover ability Health benefits High Low to medium Liabilities Possibly decrease muscle mass, speed, and power Possibly decreased cardiorespiratory function unless supported by an aerobic program Foundation Does not require anaerobic foundation Requires aerobic foundation but varies according to sport. FITT PRINCIPLE FREQUENCY – REFERS TO HOW OFTEN AEROBIC TRAINING SHOULD OCCUR - Suggested 3-5 days per week is optimal This can change as participants progressively overload their cardiovascular systems, or it may vary according to the time of the season E.g. rugby player trains aerobic during off season and tries to maintain it during season INTENSITY – REFERS TO LEVEL OF EXERCISE - Individuals should exercise at a rate sufficient to tax the aerobic system Varies between individuals general rule is heart rate between 60 per cent and 85 per cent of max heart rate TIME – REFERS TO HOW LONG TRAINING LASTS FOR Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - Once the correct intensity is reached, this should be maintained for a period of not less than 20 minutes Best results are obtained from sessions of 30–60 minutes in duration, over about 6–8 weeks Can also be for anaerobic training and how long movements should last TYPE – REFERS TO FORM OF EXERCISE THAT IS UNDERTAKEN - To improve aerobic capacity, the exercises or activities should be aerobic in nature; for example, jogging, swimming, cycling or walking. This aspect of FITT relates to the principle of specificity. LEARN TO: DESIGN AN AEROBIC TRAINING SESSION BASED ON THE FITT PRINCIPLE Training Session Plan Aerobic Activity Sport: Netball Warm up activities - Drills and games Arm, leg and full body Drill one: stretches - Passing (shoulder and chest) 100 meter slow jog - Shoulder passes: have the ball in your Dynamic stretching dominant hand and throw it from up High knees, butt kicks near the same shoulder as hand you and grapevine are using. Use only one hand when passing. Aim for the other persons chest and continue this for 30 passes - Chest passes: hold the ball with two hands in front of chest. Have hands facing the person you are passing too as if you were about to give them a high five. Grip onto the ball and aim for their chest when passing. Cool Down activities - A slow jog around the court Into a brisk walk around the court Into a stretching circle where everyone goes around the circle and does a stationary stretch Drill two: - Catching When catching hold hands in an upright position. Place thumbs together so you can see the shape of a W forming. When catching, concentrate on the ball that is being thrown to you. Have hands at the bottom of your neck and then catch the ball. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - When catching make sure you are using soft hands. Drill three: - Run a lap of the court, and then when you get next to the hoop, run in to receive a pass from a passer The catcher will then pass back, and sprint back to hoop, to then receive another pass and shoot a shot. Drill four: - Half court With eight players, everyone will get into positions, and then play a halfcourt game of netball, which is just a normal game but only using half the court FITT Justification Frequency: - Before every training session to decrease the chance of injury occurring FITT Justification Frequency - Intensity: - Low intensity - Type: - Time: - FITT Justification Frequency: Training sessions should be done at - After every training least three times a week in the session to allow the preseason to allow for aerobic fitness body to cool down to to improve, however during prevent injury competition season, sessions should Intensity: be repeated at least four times. Drill three and four: for these drills, - Low intensity the frequency in which they are performed increases as the time gets Type: shorter. I chose the stretches and Intensity: activities because they allow the body to warm - The drills need to be done at a high up to prevent injury. The intensity to allow cardiovascular stretches are done over improvement. Drill one and two are a long period of time, so done at the same intensity for a they are aerobic. month, and then intensity increases. Each week, for drill three and four, intensity increases as times get faster and harder to achieve. This allows for Time: It is done over a time optimal improvement. period of about 15 I chose the stretches and activities because they allow the body to cool down to prevent injury. The stretches are done over a long period of time, so they are aerobic. minutes to allow the Type: body to warm up properly - It is done over a time period of about 15 minutes to allow the body to cool down properly - The reason why these drills have been chosen is because they allow all the aspects of netball to be improved. The Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION first two drills are anaerobic activities when done once, but due to the nature of netball, when done over a period of time, like the drills are done, they become anaerobic training. I chose these drills because they improve both cardiovascular and muscular endurance. Drill three and four have been chosen because they allow for anaerobic improvement in all aspects. They improve cardiovascular endurance, which is vital for aerobic fitness. Time: - - Drill one and two: the first week it is done for five minutes, but as the weeks increase, the time of this drill gets longer, as cardiovascular and muscular endurance improve. By the end of the season, players should be able to do 10-13 minutes of passing and catching. Drill three and four: for these drills, as the weeks go on, the time it should take to complete the drill gets shorter. This shows that aerobic and cardiovascular fitness has improved. LEARN TO: COMPARE THE RELATIVE IMPORTANCE OF AEROBIC AND ANAEROBIC TRAINING FOR DIFFERENT SPORTS, E.G. GYMNASTICS VERSUS SOCCER Gymnastics versus soccer Aerobic training relative to soccer cardiovascular endurance needed, long and continuous Anaerobic training relative to gymnastics explosive movements needed, short, sharp movements produced Aerobic training = increase cardio, endurance, recovery from anaerobic efforts, decrease fat, fatigue Anaerobic training = increase cardio, power strength, muscle, decrease fat, Increased base aerobic fitness = increased peak fitness e.g. Aerobic = distance running, cross country skiing e.g. Anaerobic = gym, boxing field events Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION IMMEDIATE PHYSIOLOGICAL RESPONSES TO TRAINING Students learn about • Immediate physiological responses to training - Heart rate Ventilation rate Stroke volume Cardiac output Lactate levels. Students learn to • Examine the reasons for the changing patterns of respiration and heart rate during and after submaximal physical activity. IMMERDIATE PHYSIOLOGICAL RESPONSES Immediate physiological responses are the changes that take place within specific body organs and tissue during exercise. These changes are particularly observable in capacities directly related to performance, including: - Heart rate Ventilation rate Stroke volume Cardiac Output Lactate Levels CHRONIC ADAPTATIONS Chronic adaptations to training vary greatly and are dependent upon: - the type and method of training undertaken — whether it be aerobic, anaerobic or resistance training. Chronic training responses are very specific to the type of training performed. This is known as the SAID principle: ‘Specific Adaptation to Imposed Demands’. - the frequency, duration/time and intensity of the training undertaken — the greater the frequency, duration and intensity of training, the more pronounced the adaptations. However, factors such as overtraining and the principle of diminishing returns need to be considered in relation to this. - the individual’s capacities and hereditary factors (genetic make-up or potential), such as VO2 max. and muscle fibre-type distribution (fast-twitch as opposed to slow-twitch fibres). According to some research, 97 per cent of fibre types are genetically determined. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Chronic training adaptations may occur at both the system level, particularly the cardiovascular and respiratory systems, and/or within the neuromuscular system. HEART RATE Heart rate is the number of times the heart beats per minute (bpm) Resting heart rate is our heart rate when we are completely at rest. Steady State Heart rate is a period of time during which oxygen uptake remains at a uniform level, such as swimming at a constant period. Heart rate increases with exercise. This is our working heart rate. Our heart rate increases according to the intensity of our exercise effort. Maximal heart rates are observed during exhaustive exercise. A low resting heart rate is indicative of a very efficient cardiovascular system. HOW TO MEASURE HEART RATE You can measure how fast your heart is beating by taking your pulse This can be done at the wrist or the neck. VENTILATION RATE Refers to our depth and rate of breathing and is expressed in breaths per minute. When we begin to exercise, the demand for more oxygen by the muscle cells causes a ventilation response. Ventilation has two phases — inspiration, or breathing air into the lungs, and expiration, or the expulsion of air from the lungs. Ventilation rates are measured over a time period, usually one minute. A term commonly used is minute ventilation — that is, the amount of air that can be breathed in one minute. For most people this is around six litres. WHEN DOES VENTILATION RATE CHANGE? Exercise causes many immediate adjustments in the workings of the respiratory system. The rate and depth of breathing increases moderately, even before exercise begins, as the body's nervous activity heightens in anticipation of exercise. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - - Once exercise starts, the rate and depth of breathing intensifies. This is matched by an increase in oxygen consumption and carbon dioxide production, triggering elevated respiratory activity. At the end of exercise, breathing remains rapid for a short period of time, then gradually abates, finally returning to resting levels STROKE VOLUME Stroke volume is the amount of blood ejected by the left ventricle of the heart during a contraction. It is measured in mL/beat. When exercise increases, the amount of blood that the heart discharges increase considerably. Much of this is due to an increase in stroke volume. Stroke volume is determined by: - the ability to fill the ventricles by blood volume the ability to empty the ventricles as a result of ventricular contractions WHEN DOES IT CHANGE? Stroke volume increases during exercise, with most of the increase being evident as the person progresses from rest to moderate exercise intensity. As intensity increases to a high level, there is less change in stroke volume. CARDIAC OUTPUT Cardiac output is the amount of blood pumped by the heart per minute. Cardiac output increases with exercise in the same way as stroke volume. Cardiac output is a product of heart rate and stroke volume. It can be calculated in the following way: Cardiac output (CO) = heart rate (HR) × stroke volume (SV). WHAT IS CARDIAC OUTP UT? During exercise, the working muscles' demand for additional oxygen causes blood flow to be redistributed within the body. While at rest, cardiac output is directed to physically inactive muscles. However, the demands of exercise mean that the body's blood must be redirected to the muscles that are now active. - Cardiac output increases in response to physical demands being made on the body. CO for untrained people is approximately 5 litres per minute. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION • - While untrained people are able to increase cardiac output to around 20 to 22 litres per minute during exercise, highly trained endurance athletes will have an increase in the vicinity of 35 to 40 litres per minute. In addition, this increase is achieved at a slightly lower maximal heart rate. High cardiac output is better Sufficient cardiac output helps keep blood pressure at the levels needed to supply oxygen-rich blood to your brain and other vital organs. LACTATE LEVELS Lactate is a salt formed from lactic acid that accumulates during intense anaerobic activity. Lactate is a chemical formed during the breakdown of carbohydrates in the absence of sufficient oxygen. There is always a small amount of lactate circulating in the blood — about 1–2 millimoles/litre. This lactate is continually being resynthesised by the liver to form glycogen and so is of benefit in providing the body with energy. HOW DOES EXERCISE IMPACT LACTATE LEVELS? Vigorous physical exercise causes increase in levels of lactate. Lactate levels relate to the pH value of blood, which is affected by physical activity. - As exercise intensity increases, the pH level drops and acidification of muscles increases. High levels of lactate make it increasingly difficult for muscle fibres to contract. Once the lactate infliction point (LIP) is reached, further exercise results in fatigue and the subsequent inability to maintain the higher work output. If intensity is increased beyond the LIP, such as by a sprint finish at the end of an endurance event, the onset of fatigue will be even more rapid LEARN TO- REASONS FOR CHANGING PATTERNS OF RESPIRATION AND HEART RATE DURING AND AFTER SUBMAXIMAL PHYSICAL ACTIVITY Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION The reason for many of the immediate physiological responses to training is the increased amount of carbon dioxide produced by the working muscles, stimulating an increase in heart rate, ventilation, stroke volume and cardiac output. Lactate levels increase in response to an increased use of the lactic acid energy system, and the muscle’s need to remove lactate to delay fatigue. CRITICAL QUESTION 3 Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION GENERAL NOTES FOR CQ3 WHAT ARE BIOMECHANICS? Biomechanics is a science concerned with forces and the effect of these forces on and within the human body. Bio means life. Mechanics is a branch of science that explores the effects of forces applied to solids, liquids and gases. Biomechanics is very important to understanding techniques used in sport. It is of value to both coach and player because it is concerned with the efficiency of movement. A KNOWLEDGE OF BIOMECHANICS HELPS US TO: - - choose the best technique to achieve our best performance with consideration to our body shape. For instance, an understanding of the biomechanical principles that affect athletic movements, such as the high jump, discus throw, golf swing and netball shot, improve the efficiency with which these movements are made. This improves how well we perform the skill. reduce the risk of injury by improving the way we move design and use equipment that contributes to improved performance. MOTION Students learn about • Motion – The application of linear motion, velocity, speed, acceleration, momentum in movement and performance contexts Students learn to • Apply principles of motion to enhance performance through participation in practical workshops WHAT IS MOTION? Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Motion is the movement of a body (thing) from one position to another. Some bodies may be animate (living), such as golfers and footballers. Other bodies may be inanimate (nonliving), such as basketballs and footballs. We see motion in all forms of physical activity. Part of a person’s body (for example, the arm) may be moved from one position to another. The entire body may be moved from one place to another as in cycling, running and playing basketball. There are a number of types of motion: - linear angular general motion How motion is classified depends on the path followed by the moving object. LINEAR MOTION Linear motion occurs when the human body, a human limb or an object propelled by a human move in the same direction at the same speed over the same distance; for example, when running. - It is moving in a straight line ANGULAR MOTION Motion can also be classified as angular. This type of motion occurs when the human body, a human limb or an object is propelled by a human movement along a circular path about some fixed point at the same time, in the same direction and at the same angle. - It is movement along a circular path Common angular movements in sport include rotation around the high bar in gymnastics, bowling a cricket ball or the leg action in the eggbeater kick performed by water polo players. GENERAL MOTION Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Sports movements are most commonly referred to as general motion and reflect a combination of both linear and angular motion. - For example bike riding is a general motion the upper body shows Linear Motion, whilst the legs show Angular Motion, therefore a combination of motion = general motion. - E.g. swimming and sprinting events such as running - Most sports are general motion VELOCITY Velocity is equal to displacement divided by time. Displacement is the movement of a body from one location to another in a particular direction, or an ‘as the crow flies’ measurement. Velocity is used for calculations where the object or person does not move in a straight line. SPEED Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Speed is equal to the distance covered divided by the time taken to cover the distance. - Speed is important in most sports and team games. The player who can move quickly has a distinct advantage in games such as touch football, rugby and soccer because not only is that player difficult to catch, but he/she can use their speed to gather opponents quickly in defence. ACCELERATION Acceleration is the rate at which velocity changes in a given amount of time. When a person or object is stationary, the velocity is zero. An increase in velocity is referred to as positive acceleration, whereas a decrease in velocity is called negative acceleration. - E.g. a long jumper would have zero velocity in preparation for a jump. The jumper would experience positive acceleration during the approach and until contact with the pit, when acceleration would be negative. MOMENTUM Momentum refers to the quantity of motion that a body possesses. - - Momentum is a term commonly used in sport. For instance, we sometimes refer to the way in which momentum carried a player over the line in a game of football. E.g. a truck travelling at 50 kilometres per hour that collides with an oncoming car going at the same speed would have a devastating effect on the car because the mass of the truck is much greater than that of the car. The car would be taken in the direction that the truck was moving FACTORS IMPACTING COLLISIONS The mass differences of the players: Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - in most sports, we do not see the huge variations in mass that we find between cars, bicycles and similar objects Elasticity: - The soft tissue of the body, which includes muscle, tendons and ligaments, absorbs much of the impact. It acts as a cushion. Evasive skills of players: - Often result in the collision not being ‘head-on’. In some cases there may be some entanglement just prior to collision, such as a palm-off or fend. This lessens the force of impact. EXAMPLE OF CHANGE IN MOMENTUM LINEAR MOMENTUM Linear momentum is a property of a body that is moving. It is equal to (or a product of) it's mass × velocity. - Linear momentum of bodies is of little importance in sports unless the bodies collide. The result of the collision relies largely on the momentum of each body before the collision. Momentum can be transferred between bodies. ANGULAR MOMENTUM Angular momentum is the quantity of angular motion in a body or part of a body. There are numerous instances in sport where bodies generate momentum, but they do not travel in a straight line. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - For example, a diver performing a somersault with a full twist, a tennis serve, football kick, discus throw and golf swing. In each of these cases, the body, part of it, or an attachment to it such as a golf club or tennis racquet, is rotating. FACTORS THAT AFFECT ANGULAR MOMENTUM Angular momentum is affected by: - - - Angular velocity o For example, the distance we can hit a golf ball is determined by the speed at which we can move the club head. The mass of the object. o The greater the mass of the object, the more effort we need to make to increase the angular velocity. It is relatively easy to swing a small object such as a whistle on the end of a cord. Imagine the effort that would be needed to swing a shotput on a cord. The location of the mass in respect to the axis of rotation. o With most sport equipment, the centre of mass is located at a point where the player is able to have control and impart considerable speed. Take baseball bats and golf clubs for example. Here, the centre of mass is well down the shaft on both pieces of equipment. This location enables the player to deliver force by combining the mass of the implement at speed in a controlled manner, thereby maximising distance. BALANCE AND STABILITY Students learn about Students learn to Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION • Balance and stability - Centre of gravity Line of gravity Base of support • Apply principles of balance and stability to enhance performance through participation in practical workshops STABILITY Stability is concerned with the resistance of a body to changes in its equilibrium; that is, changes in its linear or angular acceleration. When an individual can assume a stable position and then control that position, he or she is said to be in a state of balance. There are two types of balance: - If the body is at rest (not moving) it has static balance. If the body is moving, it has dynamic balance. THE CENTER OF GRAVITY The centre of gravity of an object is the point at which all the weight is evenly distributed and about which the object is balanced. Knowing the position of the centre of gravity is very important to improving sport performance. In a igid object such as a cricket ball or billiard ball, the centre of gravity is in the centre of the object. This means that the mass is equally distributed around this point; that is, the weight is equally balanced in all directions. If the object has a hollow centre, such as a tennis ball or basketball, the centre of gravity is located in the hollow centre of the ball Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION The centre of gravity is different in different bodies. - E.g. tenpin bowling balls when the object is rolled on a flat surface, it gradually moves in the direction of the side with the greater mass. STATIC BALANCE Static balance activities such as headstands and handstands require precise manipulation of the centre of gravity. - To balance on your hands as in a handstand, or on your head and hands as in a headstand, the centre of gravity must be controlled by the base of support. If it moves away from a perpendicular position directly over the base, the gymnast falls. DYNAMIC BALANCE Dynamic balance activities also require skilful control of the centre of gravity. In many moving activities, such as skiing and surfing, there is a fine line between the balance necessary for control and loss of balance resulting in a fall. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LINE OF GRAVITY The line of gravity is an imaginary vertical line passing through the centre of gravity and extending to the ground. It indicates the direction that gravity is acting on the body. When we are standing erect the line of gravity dissects the centre of gravity so that we are perfectly balanced over our base of support. MOVEMENT IN RELATION TO LINE OF GRAVITY Movement occurs when the line of gravity changes relative to the base of support. Movement results in a momentary state of imbalance being created, causing the body to move in the direction of the imbalance. - In specialised sporting movements, such as the start in athletics, diving and rhythmic gymnastics, the precision with which the line of gravity moves in relation to the base of support directly affects the quantity and quality of movement. During practice of specialised skills, athletes progressively develop a feel for the line of gravity relative to the base of support, enabling the controlled instability required for movement. This means that less force is required to initiate the desired movement. THE BASE OF SUPPORT Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION The base of support refers to an imaginary area that surrounds the outside edge of the body when it is in contact with a surface. It affects our stability or our ability to control equilibrium. - - A narrow base of support allows the centre of gravity to fall close to the edge of the base of support. Only a small force is needed to make the person lose their balance. A wide base of support is essential for stability because the centre of gravity is located well within the boundaries. EXAMPLE INCORPORATING ALL OF BALANCE AND STABILITY FACTORS HOW DO ATHLETES USE THEIR BASE OF SUPPOR T? Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - Gymnasts performing a pirouette have a very narrow base of support and must work hard to ensure that their centre of gravity remains within the base. Wrestlers widen their base of support to prevent their opponents from moving them into a disadvantageous position. Tennis players lower the centre of gravity and widen the base of support in preparation to receive a fast serve. This enhances balance and enables the centre of gravity to be moved in the desired direction more readily. Swimmers on the blocks widen their feet and move the centre of gravity forward to improve their acceleration. Golfers spread their feet to at least the width of their shoulders to enhance balance when they rotate their body during the swing. - - FLUID MECHANICS Students learn about • Fluid mechanics – Flotation, centre of buoyancy – Fluid resistance Students learn to • Apply principles of fluid mechanics to enhance performance through participation in practical workshops • Describe how principles of fluid mechanics have influenced changes in movement and performance, e.g. technique modification, clothing/suits, equipment/apparatus WHAT ARE FLUID MECHANICS? Fluid mechanics refers to forces that operate in water and air environments. These forces will affect how well we can move through the water (either in a vessel or as a swimmer) or how we can move ourselves or projectiles through the air. - Two important forces influence our ability to perform effectively in a water environment: buoyant force and drag force. The type of fluid environment we experience impacts on performance. - For example, when we throw a javelin, hit a golf ball or swim in a pool, forces are exerted on the body or object and the body or object exerts forces on the surrounding fluid. BOYANCY Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Buoyancy an upward force on the body experienced when the body is immersed in water. The effect of buoyancy is to reduce the apparent weight of the body by opposing gravity. The principles of flotation were described more than 2000 years ago by a Greek mathematician named Archimedes. Archimedes’ Principle states that when a body is immersed in water, the body experiences an upwards force equal to the weight of water displaced by the body. - Someone who weighs less than the water they displace will be able to float easier CENTER OF BOYANCY Centre of buoyancy is the centre of gravity of a volume of water displaced by an object when it is immersed in that water. The centre of buoyancy is at the centre of gravity of the water that the swimmer displaces. When the body is fully submerged, the centre of buoyancy of the swimmer will fall directly above the swimmer’s centre of gravity. The centre of buoyancy and centre of mass will also change as a result of the movement changes, particularly the legs. Lift force occurs perpendicular to the flow of water/air FLUID RESISTANCE When we move through a fluid (air or water), we have to push that fluid aside as we move through it. This creates resistance on the body that tends to slow our movements. This is often called a drag force. - Drag is the force that opposes the forward motion of a body or object, reducing its speed or velocity. FACTORS THAT AFFECT AMOUNT OF DRAG THE Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION - Fluid density because water is denser than air, forward motion in this fluid is more difficult. Shape if a body or object is streamlined at the front and tapered towards the tail, the fluid through which it is moving experiences less turbulence and this results in less resistance. Surface a smooth surface causes less turbulence, resulting in less drag. Size of frontal area if the front of a person or object (area making initial contact with the fluid) is large, resistance to forward motion is increased. SURFACE DRAG Surface drag is caused by friction between the surface of an object and the fluid surrounding it. - A larger surface area or a rougher surface will increase the amount of surface drag present. E.g. rowing boats, are highly polished, creating a smooth surface that water can flow past easily. PROFILE DRAG (ALSO CALLED FORM OR PRESSURE DRAG) Refers to drag created by the shape and size of a body or object. - - Bodies or objects cause the medium to separate when moving through fluids, resulting in pressure differences at their front and rear. The separation causes pockets of high and low pressure to form, resulting in the development of a wake or turbulent region behind the body or object. Pressure drag is a component of the total drag, all of which combine to slow down the object. E.g. cyclists try to reduce form drag by reducing the size of their frontal area (bending forward) and by ‘drafting’ or following closely behind other cyclists to reap the benefits of being in the low pressure area. LEARN TO - THE EFFECTS OF DRAG ON PERFORMANCE IDENTIFY TYPES OF DRAG Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Profile drag (bent over action reduces profile and increases speed) Surface drag (lycra, helmets to increase speed) and profile drag (hunched body shape to reduce drag and increase speed) WHAT HAS BEEN DONE TO MINIMISE RESISTANCE FORCES? Much has been done to try to minimise resistance forces that oppose movement in fluid mediums. Most developments have taken place in regard to technique, tactics, clothing and equipment design. For example: - Technique cyclists, speed skaters and downhill skiers all bend forward at the trunk. Tactics distance runners and cyclists follow one another closely where possible. Clothing tight bodysuits made of special friction-reducing fabrics are worn by runners, cyclists and swimmers. Equipment design designs of equipment such as golf balls, golf clubs, cricket bats, bicycle helmets, footballs and surfboards are continually being modified to make them more aerodynamically efficient. LEARN TO – WHAT HAS BEEN DONE TO REDUCE DRAG? Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Profile drag: When we swim, for example, fluid pressure at the front of our body is greater than fluid pressure behind our feet. Objects with bigger cross-sectional areas produce more form drag Profile drag: Streamlined objects which, because of their shape and smoothness, cause less drag. Surface drag: wearing swim suits, swim caps, and shave their bodies to reduce the resistance caused by drag THE MAGNUS EFFECT The Magnus effect explains why spinning objects such as cricket and golf balls deviate from their normal flight paths. When an object such as a cricket ball or golf ball is bowled or hit into the air, its spinning motion causes a whirlpool of fluid around it that attaches to the object. According to the direction of spin, the object’s movement is affected. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION LEARN TO- HOW THE MAGNUS EFFECT AFFECTS THE FLIGHT OF DIMPLED AND NONDIMPLED GOLF BALLS The Magnus effect is the aerodynamic force generated by the spin of the axis of the golf ball that is perpendicular to the flight path of the ball. The dimples add to this effect, adding energy to your hook or slice. Dimples on a golf ball help promote a symmetrical flow pattern, which increases lift. Dimpled golf balls have reduced drag. The dimples keep the layered air around the ball longer, creating a smaller vortex and thus more turbulent energy, which equals less drag. FORCE Students learn about • Force - How the body applies force How the body absorbs force Applying force to an object. Students learn to • Apply principles of force to enhance performance through participation in practical workshops. WHAT IS FORCE? Force (biomechanics) is the push or pull acting on a body. Forces can be considered as a push or a pull, a blow or an impact, friction when two surfaces rub together or gravity. - Players are able to apply forces (biomechanics) to objects such as the ground to enable them to run faster, or to a tennis racquet to enable them to hit the ball harder. In doing this, the players are confronted with opposing forces such as gravity, air resistance and friction. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION INTERNAL FORCES Internal forces are those that develop within the body; that is, by the contraction of a muscle group causing a joint angle to decrease. - For example, the contraction of the quadriceps when kicking a football. EXTERNAL FORCES External forces come from outside the body and act on it in one way or another. - For example, gravity is an external force that acts to prevent objects from leaving the ground. PROPERTIES OF FORCES All forces have four common properties. - Magnitude an amount; how much is applied Direction the angle at which the force is applied Point of application the specific point at which the force is applied to a body Line of action represents a straight line through the point of application in the direction that the force is acting HOW DOES THE BODY APPLY FORCE? Newton’s First Law of Motion - - Everybody continues in its state of rest or motion in a straight line unless compelled to change that state by external forces exerted upon it. Basically, no force means there is no movement Inertia: Inertia resists change in motion. Objects want to stay in rest or motion unless an outside force causes a change. For example, if you roll a ball, it will continue rolling unless friction or something else stops it by force. Newton’s Second Law of Motion - The rate of change in motion of a body is proportional to the force causing it, and the change takes place in the direction in which the force acts. This law means that a body will experience a change in its motion in proportion to the force applied to it, and in the direction of the force. For example, a golf ball putted on a green moves in the direction in which it is hit and according to how hard it is hit. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION Newton’s Third Law of Motion - - For every force that is exerted by one body on another, there is an equal and opposite force exerted by the second body on the first. You may have heard the saying ‘For every action there is an equal and opposite reaction’. This is another way of saying Newton’s Third Law. This law illustrates that forces act in pairs and are equal and in opposite directions. However, the result is not always the same. For instance, when you land after performing a long jump, you apply a force to the ground, and it applies one back to you. The effect on you is much greater than your effect on the ground because the earth is much bigger and heavier. In this way, Newton’s Third Law relates to the Second Law. COMPARING FORCES APPLIED AND REACTION FORCES Applied forces are forces applied to surfaces such as a running track or to equipment such as a barbell. When this happens, a similar force opposes it from outside the body. This is called a reaction force. - - The result is that the runner is able to propel his or her body along the track surface because the applied force generated by the legs is being matched equally by the reaction force coming from the track surface. The greater the force the runner can produce, the greater is the resistance from the track. The result is a faster time for the distance. This is explained by Newton’s third law: ‘For every action, there is an equal and opposite reaction’. In other words, both the runner and the track each exert a force equal to whatever force is being applied. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION HOW DOES THE BODY ABSORB FORCE? Forces exerted on the body are absorbed through the joints, which bend or flex in response to the impact. When the body lands on a floor or similar surface, it exerts a force on the surface. In response, the surface exerts a force on the body. If we did not bend the knees and allow a slow, controlled dissipation of the forces by the muscles, the risk of injury to the joint would be increased. - In an activity such as the landing phase of a long jump, the muscles in the front of the thigh (quadriceps) lengthen while absorbing the force. Joint flexion helps prevent injury to surrounding tissue. The body also absorbs forces while catching balls or similar objects. In the process of catching, a force is exerted by the ball on the hand and a force is exerted by the hand on the ball. To increase the catching distance and thereby absorb the force more effectively, we can use a number of techniques, including: - the catching arm can be outstretched. When the ball meets the hand, the arm can be drawn quickly to the body. Lucy Warren PDHPE STUDY NOTES – UNIT 2 – THE BODY IN MOTION APPLICATION OF FORCE ON AN OBJECT A range of techniques can be employed to make the body increase the force it exerts in physical activity or make the play harder to return or intercept. LEARN TO - HOW TO INCREASE FORCE IN A SPORT (TENNIS SERVE) The tennis player can increase acceleration (racquet speed) and power to the serve to generate more force. An effective leg drive will increase hitting height by allowing impact to occur off the court. LEARN TO – WHY IS DEVELOPMENT OF FORCE AN ADVANTAGE? Development of force is an advantage, as most sports involve an action that changes or tends to change the motion of an object. Lucy Warren
