What is it? Why do we study it? Sports Biomechanics What is it? Why do we study it?

What is Biomechanics Sub-discipline of Kinesiology- study of human movement Study of the movement of living things using the science of mechanics Branch of physics that is concerned with the description of motion and how force creates motion

Why study Biomechanics? Improve Performance Preventing and Treating Injury Qualitative and Quantitative Analysis

Improve Performance Most useful in sports where technique is the dominant factor Physical stature and physiological capacity are a more dominant factor in many sports Example: Running Equipment design Exercise movements and training devices

Preventing and Treating Injury Medical property of tissue Mechanical loadings during movement Preventative or rehabilitation therapies Shoes Helmets Prosthetics Orthotics Support objects or braces that correct deformities or joint positioning

Qualitative and Quantitative Analysis Systematic observation and introspective judgement of the quality of movement Easier, more commonly used Quantitative Numerical Measurement of biomechanical variables Accuracy, consistency, and precision

Mechanics Rigid-body Deformable-body Fluids Small deformations in shape so small they can be ignored Reasonable assumption for Biomechanics Most used Deformable-body How forces are distributed within a material Fluids Concerned with forces in fluids Liquids and gasses Air resistance

Rigid-Body Statics- study of objects at rest or in uniform motion Dynamics- study of objects being accelerated by the actions of force Kinematics Motion description Measured in linear or angular terms Kinetics Determining the cause of motion Forces and air resistance

9 Fundamentals of Biomechanics Force-Motion Force-Time Inertia Range of Motion Balance Coordination Continuum Segmental Interaction Optimal Projection Spin

Force-Motion Says that unbalanced forces are acting on our bodies or objects when we either create or modify movement Quiet standing- what forces are equal in this? No change in motion, since there is no unbalanced force acting on the individual

Force-Time The amount of time over which force can be applied affects motion Examples: Bowling, javelin, throwing Impulse-momentum relationship Increasing time to apply force to slow down objects in motion Newton’s Second Law

Inertia Property of all objects to resist changes in their state of motion Newton’s First Law At rest, or in motion, unless acted on by an outside force

Range of Motion Overall motion used in a movement Increasing range of motion can increase speed or gradually slow down Related to force-time

Balance Person’s ability to control their body position relative to base of support Stability and mobility of body postures are inversely related Less stable=more mobile Mores stable=less mobile

Coordination Continuum Muscle actions and body segment motions are timed Determining the optimal timing of muscle actions or segmental motions depends on the goal of the movement High forces- more simultaneous actions Low-force and high-speed- more sequential actions

Segmental Interaction Forces acting in a system of linked rigid bodies can be transferred throughout the links and joints Muscles coordinate to complement the effects of torques created at joints

Optimal Projection Most human movements involving projectiles have an optimal range of projectile angles for specific goals Optimal angles proved the right compromise between vertical velocity and horizontal velocity

Spin Rotations imparted to projectiles Spin is desirable for stabilization and fluid force called lift Lift force is used to create a curve or counteract gravity

4 Steps of Qualitative Analysis Preparation Gather relevant knowledge Select observational strategy Observation Executes the observational strategy to gather relevant sensory information Evaluation/Diagnosis Evaluation- identify strengths and weaknesses Diagnosis- prioritizing of the potential interventions Intervention Executes some action on behalf of the performer