Kinesiological Principles - Lecture 1 PDF

What is a Force? KINESIOLOGICAL PRINCIPLES 1 A force is a push or a...

What is a Force? KINESIOLOGICAL PRINCIPLES 1 A force is a push or a pull EXTERNAL PART 1: CLASSIFYING FORCE INTERNAL 2 Forces come in pairs: action and reaction 3 Causes change in movement LEE WALLACE PhD LEE WALLACE PhD Measuring Force Forces Effecting Movement Force (F) is measured in Newtons (N) Gravity Friction Drag Between body and other.. LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD Forces Effecting Movement Non-Contact Force Weight Force (FWT) EXTERNAL The only non contact force in sport/exercise is the force of gravity NON-CONTACT CONTACT FORCE FORCE Acts through Centre of Gravity (COG) GRAVITY 1. NORMAL CONTACT (WEIGHT FORCE) 2. FLUID CONTACT 3. FRICTION LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD 1  Contact Force Classifying Force Contact forces are the forces that occur between objects in contact with each other NORMAL CONTACT FLUID CONTACT FRICTION EXTERNAL INTERNAL NON-CONTACT CONTACT TENSILE COMPRESSIVE FORCE FORCE FORCE FORCE SHEAR FORCE GRAVITY 1. NORMAL CONTACT (WEIGHT FORCE) 2. FLUID CONTACT 3. FRICTION Or Ground Reaction Force Parallel to normal contact LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD Internal Force Tensile Force Mechanical loads of the human body A pulling force which acts on the ends of an internal structure Muscle forces, gravitational forces and bone breaking forces – e.g. Ligaments and tendons have differing effects on the human body. These generate internal forces LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD Tensile Force Compressive Force A pushing force which acts on the ends of an internal structure – e.g. Bones and joints LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD 2 Compressive Force Shear Force A transverse force that acts in parallel to the analysis plane A pushing force which acts on the ends of an internal structure – e.g. Bones and joints LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD Shear Force A transverse force that acts in parallel to the analysis plane Too much tensile/compressive/shear force will cause the structure to deform/break LEE WALLACE PhD LEE WALLACE PhD Torque and Moment Vectors KINESIOLOGICAL Torque: The turning effect PRINCIPLES produced by force – Often referred to as a moment (𝑟) represents moment arm PART 2: LEVER SYSTEMS ↑ 𝑟 = ↑ mechanical advantage LEE WALLACE PhD LEE WALLACE PhD 3 Muscular Torque Muscular Torque Muscles create torque that turns limbs eg. The Biceps Brachii exerts a torque around the axis of the elbow LEE WALLACE PhD LEE WALLACE PhD Components of a Lever System Components of a Lever System Within the lever system there are 3 parts Within the lever system there are 3 parts FULCRUM ORpivot Fulcrum or PIVOT THE LOAD THE EFFORT Load Effort Fulcrum LEE WALLACE PhD LEE WALLACE PhD 1st Class Lever Components of a Lever System Load Effort The fulcrum lies between the load and the effort Load - Fulcrum - Effort Fulcrum Trade-off between Distance and Force LEE WALLACE PhD LEE WALLACE PhD 4 Components of a Lever System Components of a Lever System Less effort to lift load but does not move as great a distance Greater effort to lift load but moves a greater distance Load Effort Load Effort Fulcrum Fulcrum LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD 1st Class Lever 2nd Class Lever The load lies between the fulcrum and the effort Fulcrum - Load - Effort Force Multipliers LEE WALLACE PhD LEE WALLACE PhD 2nd Class Lever 3rd Class Lever The effort lies between the load and the fulcrum Load - Effort - Fulcrum Distance Multipliers LEE WALLACE PhD LEE WALLACE PhD 5 3rd Class Lever LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD 6  LEE WALLACE PhD LEE LEEWALLACE WALLACEPhD PhD 1st Class 2nd Class 3rd Class KINESIOLOGICAL PRINCIPLES The fulcrum lies between The load lies between the The effort lies between PART 3: JOINT ACTIONS, the load and the effort fulcrum and the effort the load and the fulcrum MUSCLE CONTRACTIONS Load - Fulcrum - Effort Fulcrum - Load - Effort Load - Effort - Fulcrum Distance and Force Force Distance LEE LEEWALLACE WALLACEPhD PhD LEE WALLACE PhD LEE WALLACE PhD 7 Muscle Actions Muscle Actions What is the action of the shoulder during the up phase? What type of contraction occurs in the latissimus dorsi? Concentric Eccentric Isometric LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD Muscle Actions Muscle Actions What is the action of What is the action of the shoulder during the shoulder during the down phase? the down phase? What type of What type of contraction occurs contraction occurs in the latissimus in the deltoid? dorsi? LEE WALLACE PhD LEE WALLACE PhD Muscle Actions Muscle Actions What is the action of What is the action of the knee during the the hip during the down phase? down phase? What type of What type of contraction occurs contraction occurs in the quadriceps? in the glutes? LEE WALLACE PhD LEE WALLACE PhD 8 Muscle Actions Readings Nordin and Frankel (2012): Chapter 1 What is the action of the shoulder during the return phase? What type of contraction occurs in the horizontal adductors? Images in this presentation were used with permission: Nordin, M. & Frankel, V. H, (2012), Basic Biomechanics of the Musculoskeletal System (4th ed), Lippincott Williams & Wilkins, Baltimore. LEE WALLACE PhD LEE WALLACE PhD LEE WALLACE PhD 9