Lesson 1, Topic 1
In Progress

Biomechanics based coaching

Competence of the coach to make informed decisions/ability to know/understand the basic cause(s) for technical efficiency.

Newton’s Third Law of Motion

  • “For every action there is an equal and opposite reaction.”

Breaking forces

  • To be Minimised at touch down Every running & sprinting stride
  • Hurdle & Steeple Clearance
  • Hop & Step (TJ)

To be Maximize at blocking action of delivery phase

Javelin ,Discus ,Shot Put  

Competence of coach to make informed decisions / ability to

  • Apply / Identify basic biomechanics of Technical Model
  • Evaluate the athletes actual technic vs. Technical Model
  • Identify technical mistake(s) and understand their cause(s)
  • Choose appropriate corrections/drills
  • Identify / train performance determining factors of the event

For example Jumps (Take Off)

  • Limited Contact time – Speed Strength / Max Strength
  • Transferable Vhor”    – Speed Strength / Max Strength

What is the correct technique ?

To copy the technique of current champions?

Consider that world’s best athletes have:?

World Champions have different techniques, some “good” parts, some “bad” parts how do you tell the good from the bad: biomechanics

Techniques that suit their individual:

  • Strengths
  • Weaknesses
  • Fitness
  • Flexibility

Biomechanical language

Force   – simply a pull or a push

Types of Motion

  • linear motion
  • rotational motion
  • general motion

Velocity   – how fast and which direction

Acceleration   – how fast velocity is increasing

Deceleration   – how fast velocity is decreasing

100m Sprint velocity

Look at the speed-time graph for the 100m sprinter:

  • How many seconds is the sprinter accelerating?
  • What is the sprinter’s velocity after 2 seconds?
  • What is the sprinter’s velocity after 6 seconds?
  • After how many seconds does the sprinter start decelerating?

Momentum

  • Momentum – is the quantity of motion a body has:
  • Momentum = Weight x Velocity
  • Angular Momentum – is the quantity rotational motion:
  • Angular Momentum = Moment of Inertia x Rotational Velocity

Moment of Inertia – is simply related to size or length

  • Reducing the size will  increase rotational velocity (arms in sprinting; legs in hammer throw)
  • Increasing the size will reduce rotational velocity(flight in the long Jump).

Summation of forces

  • Use all the joints that can be used
  • Coaches’ Eye Take Off: “Full Extension
  • Use every joint in order.

Laws of motion

Newton’s First Law of Motion

“All bodies continue in a state of rest or uniform motion in a straight line unless acted upon by some external force”

Newton’s Second Law of Motion

  – Law of Acceleration

“The acceleration of a body is proportional to the force causing it and takes place in the direction the force acts”

Newton’s Third Law of Motion

  – Law of Reaction

“To every action there is an equal and opposite reaction.”

Law of reaction (Runners creating equal and opposite reactions)

Center of gravity

The athlete passes over the bar while his center of gravity passes through or beneath it.

Athletes or implements flying in the air

The parabolic flight path depends on:

  • Speed of take-off or release V0
  • Angle of take-off or release
  • Height of the Centre of Gravity at release
The parabolic flight path for various release angles