Biomechanics of Ice Hockey Slap Shot

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Biomechanics of Ice Hockey Slap Shot

• Chantelle Frechette
• Kathy Palmer
• Megan Suyematsu
• Raven Ladon
• Essy Sosa
• Sean Griffin
• StevieG.
• Matt Barrett

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Introduction

• The slap shot is one of several scoring skills
  used in hockey.
• Most commonly used by a defenseman, especially
  during a power play. In certain circumstances
  forwards do use the shot, and it can be very
  beneficial.

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Methods BU Ice Hockey Training Center

• Goal
• Hockey stick
• Puck
• Athlete

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6 Phases of Slap shot

• Backswing
• Downswing
• Pre-loading
• Loading
• Release
• Follow through

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Phase 1- Backswing
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Phase 2-4
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Phase 5 and 6
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Muscles Involved

• Shoulder Adduction
• Pectoralis Major
• Latissimus Dorsi
• Teres Major
• Shoulder Flexion
• Anterior Deltoid
• Shoulder Internal Rotation
• Pectoralis Major
• Subscapularis
• (Emmert, 1984)

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Muscles Involved

• Trunk Rotation
• Internal/External Obliques
• Hip Flexion
• Psoas
• Iliacus
• Pectineus
• Elbow Extension
• Triceps Brachii
• Forearm Pronation
• Pronator Quadratus
• Wrist Flexion
• Flexor Carpi Radialis Ulnaris
• (Emmert, 1984)

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Agonist, Antagonist, Synergist, Stabilizer, and
Neutralizer

• Neutralizers
• Deep back muscles
• Stabilizers
• muscles of the lower extremities mainly the
  front leg
• Agonists
• Right External Oblique and Left Internal Oblique
• Antagonists
• Left External Oblique and Right Internal Oblique
• Synergists
• Abs assisting (Transverse and Rectus)Peri
  Spinals and Quadratus Lumborum

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Types of Muscle Contractions

• Trunk Rotation
• Eccentric stabilizers
• - Internal obliques
• -External obliques
• -Rectus abdominis
• -Transverse abdominis
• The lumbar region produces the major
  flexion/extension pivot point for the trunk.
• (Neumann, D.A., 2002)

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Rotation

• Pelvic on Femoral Rotation
• Only 5 degrees of horizontal plane rotation
  occurs to each side of the lumbar region.
• 1.1 degrees of unilateral axial rotation measured
  in the lumbar region. This is limited due the
  apophyseal joints located controlateral to the
  side of the rotation.
• Backswing
• Internal Obliques cause ipsilateral rotation of
  the trunk
• Downswing, Pre-loading, loading, release and
  follow through
• External Obliques cause contralateral rotation
  of the trunk
• Axis of Rotation
• Lumbar Spine
• (Neumann, D.A., 2002)

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Major External/Internal Forces

• Summation of forces
• More than just muscle action
• Car wreck analogy

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Radius of Gyration

• Radius of Gyration is the average distance
  between the Axis of rotation and the center of
  mass of the body.
• The greater the radius of rotation of the upper
  body about the longitudinal axis of the trunk,
  the greater the inertia, or resistance to
  rotation, of the trunk and the slower the
  movement.
• The weight of the stick and upper limbs remains
  constant, therefore, any increase in the radius
  of gyration results in an increase in inertia, or
  the resistance of a body to rotate.
• (Hall, 1999)

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Lever Systems

• It is possible that the more the player takes
  advantage of the first class lever, the greater
  the height of the shot as the lever projects the
  blade of the stick rapidly in the vertical
  direction. Whether the player is executing a high
  or low shot, it appears the stick serves as both
  a 1st and 3rd class lever throughout the
  movement. The head should be rotated towards the
  target and the eyes should be looking for an
  opening on the goaltender throughout this
  movement.

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Torque Velocity

• Torque Force x moment arm (rotational force
  applied to the axis of rotation, through a moment
  arm).
• The rotation produces torque on the puck. Hip
  rotation causes the torque force to change the
  angular velocity of the stick.
• -the angle in which the force is applied is
  directly related to the distance.
• During the follow-through phase, the further out
  on the blade, the more torque, or twisting force,
  there is.
• -The faster your stick is going at the bottom
  of your swing, the greater the amount of kinetic
  energy transferred from stick to puck.
• (Falconer, 1994)

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Newtons First Law

• A force is needed to change the direction of the
  object, and time force must act in the direction
  of the change.
• - Force is generated by the rotation of the
  trunk to move the stick in the direction the puck
  wants to go.

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Trajectory and Speed of Puck

• Determined by
• Impulse on puck
• Acceleration of puck
• Contact time with the puck
• Forces exerted by player
• Stiffness of stick
• (Villasenor, 2006)

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Deflection of Stick Shaft
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Power and Work

• The slap shot is mostly technique and power comes
  from the weight transfer from the players back
  leg, right through to the stick in his hands.

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Things to Consider When Designing a Conditioning
Program

• Flexibility and eccentric strength in the hips,
  core and shoulder complex are needed to properly
  rotate through the hips and alleviate stress on
  the lumbar spine to transfer forces through the
  core and produce optimal angular velocity at the
  shoulder.
• Pivoting or rotating on a fixed foot requires
  optimal internal and external rotation at the
  hips as well as stabilization and strength in the
  transverse plane.
• Increased forces placed on the lower extremities
  during stopping, starting and pivoting require
  high levels of stabilization and eccentric
  strength in the ankle, knee, and hip
• Focus on increasing aerobic endurance, anaerobic
  power and endurance, muscle strength and skating
  speed.
• (In Pro-Form)

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Conditioning ProgramDay 1-2
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Conditioning Program Day 3-4
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Questions

• 1. Of the 6 phases of the slap shot, which of one
  of the four dont belong?
• a. follow thru
• b. preload
• c. impact
• d. load
• 2. The main stabilizers in the slap shot action
  take place in the upper extremities?
• True or False
• 3. What is the major action of the rotation of a
  slap shot?
• a. pelvic on femoral
• b. femoral on pelvic
• c. in the knees
• d. in the wrist

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Questions

• 4. which factors determine the trajectory or
  speed of the puck when struck?
• a. impulse on puck
• b. contact time
• c. stiffness of stick
• d. all the above
• 5. what lever system (s) are used during the slap
  shot action
• a. 1st class lever system
• b. 2nd class lever system
• c. 1st and 3rd class lever systems
• d. all the above

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References

• Villanseñor, A., Turcotte, R.A., Pearsall, D.J.
  (2006). Recoil effect of the ice hockey stick
  during a slap shot
• Pearsall, D.J., Montgomery, N., Turcotte,
  R.A.(1999). The influence of stick stiffness on
  the performance of ice hockey slap shots
• Emmert, W. (1984). The slap shot- strength and
  conditioning program for hockey at Boston
  College. National College of Sports Medicine
  Journal, 64-73.
• Montgomery, DL.(1998) Physiology of Hockey.
  Sports Medicine, February 5(2) 99-126
• Falconer, T.(1994) How Hockey Works. Equinox.
• In Pro-Form
• Mike Boyle
• Ed Perkins