Scientific Method of Problem Solving by 815MfXx

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									   Scientific Method of Problem Solving
• Develop (define and delimit) the problem
• Formulate the general hypothesis:
   – Overload training improves strength
   – (e.g., 3 sets of bp 3 d/w will improve bp strength)
• Formulate the specific hypothesis:
   – If A (general) is true, then B (specific) will be true
   – (e.g., if the general hyp is true, then posttest > pretest)
• Gather , analyze, and interpret the data
   – If B is true (significant difference), what about A?
   – If B is not true (no sig diff), what about A?
• Discuss the results
   – Is B without A very unlikely, or are there alternative
     explanations?
  Sport biomechanics – outline
• Reading assignments:
  – Kreighbaum & Barthels – Module J (pp 335-
    353, Ch 11 (pp 370-384), esp pp 372-375 on
    baseball pitch
  – Adrian – Ch 17, esp pp 333-339, Ch 18, esp
    365-369
   Biomechanical correlates of participation in
       sports: areas of interest and effort
• Evaluate process – technique – optimize efficiency, or
  outcome
• Injury potential/prevention
• How to enhance acquisition of sport skills– motor learning
• Design appropriate conditioning programs to enhance
  performance
• Equipment Design and Selection
   –   ground-foot interfaces
   –   protective equipment (pads, gloves, head gear)
   –   striking implements
   –   balls
   –   Sports playing surfaces
      Exercise and Sport Biom Prof Org
•   American College of Sports Medicine
•   International Society of Biomechanics in Sports
•   Biomechanics academy of AAHPERD
•   North American Society of Biomechanics
•   International Association for Sports Surface Sciences
•   International Society of Biomechanics
•   American society of Biomechanics
•   Canadian Society of Biomechanics
•   European Society of Biomechanics
•   Formosan Society of Biomechanics
•   International Sports Engineering Association
•   International Shoulder Group
•   ISB Technical Group on the 3-D Analysis of Human Movement.
•   European Society for Movement Analysis in Adults and Children
           Sport biomechanics journals
•   Research quarterly for exercise and sport
•   Medicine and science in sport and exercise
•   Journal of applied biomechanics
•   Sports biomechanics
•   International journal of sport and health science
•   Journal of sports sciences
•   Sports engineering
•   Pediatric exercise science
•   Journal of orthpaedic and sport physical therapy
•   Journal of biomechanics
•   Journal of athletic training
•   Journal of strength and conditioning research
•   Journal of electromyographic kinesiology
•   Sports medicine
      Throwlike and Pushlike Movement Patterns
• Usual objectives of throw and push patterns
      • projection of objects for greatest horiz or vert dist
          – ex : javelin, discus, shotput
      • projection of objects for accuracy with speed a factor
          – ex: volleyball, tennis, racquetball, baseball pitch
• Movement pattern terminology review
      • Throwing patterns are further defined as underarm, sidearm, or overarm
        Skills listed under each pattern differ because of constraints
          – ex: rules governing implement or ball, rules governing target.

• Open and Closed chain movements
      • Open kinetic chain - sequential segmental action, end segment is free to
        move (e.g., baseball pitch)
      • Closed kinetic chain - simultaneous end segment movement, end segment
        meets with “considerable resistance “ (e.g., shot put)
Common movement patterns
       Throwlike and Pushlike Movement Patterns
• Characteristics of throw-like patterns
   – can be a strike or a kick
   – high end-point velocity is critical
   – sequential segmental action, object lags behind elbow and/or shoulder
• Open kinetic link model - Figure J.1, p 338; J.2, p 339
• Linear motion of a point on a rotating segment: V = r
• Sequencing segmental rotations - kinetic link principle
   –   system has a base and a free open end
   –   segmental masses progressively decrease
   –   an external torque is applied at the base to initiate the movement
   –   segmental rotational acceleration is timed sequentially
• A model of an open kinetic link system - Fig J.4, p 343
• Throwlike movements performed while in the air - Fig J.5, p 345
Three-segment kinetic link model
 Three-
segment
 model:
(Fig j.2,
 p 339)
Whip-like action of segmental system
Three-segment model when
         airborne:
Throwing motion (sequential)
Segmental sequence when throwing
Phases of pitching:
1.   Windup (a-k)
2.   Early Preparation (l-m)
3.   Late preparation (n-p)
4.   Release (r-u)

From: Feltner, M. & Dapena,
J. (1986) Dynamics of
shoulder and elbow joints of
the throwing arm during a
baseball pitch. Int J Biomech
235-259.
Javelin – similar
To baseball pitch
Shotput – some throw
        & some push
American
 Sports
Medicine
Institute
analyzes
pitching
(www.asmi.org)
The kinetic chain illustrated in
        baseball pitch
Poor technique can cause both
 injury and poor performance
       Throwlike and Pushlike Movements
• Pushlike patterns - Simultaneous segmental actions
   – Objective is accuracy, or large motive force
   – Distal segments move simultaneously, resulting in rectilinear
     movement of distal segment
   – Four differences in throw and push. In throws:
      • distal segment “lags back”, segments move sequentially, object moves
        curvilinearly, wheel-axle movements (shoulder and hip rotation) involved
• Movements lie on a throw-push continuum, the location
  depending on constraints of performer and object:
   – performer strength and skill
   – object mass, size, and shape
Pushing Motions
Development of throwing motion
Developmental stages of throwing

• Stage 1- ball thrown primarily with elbow
  extension – no rotation of thorax or arm
• Stage 2 - Thoracic rotation accompanies backward
  motion of the arm. The throw is initiated by the
  arm swing forward. Some arm rotation as well as
  forearm extension at various times
• Stage 3 - step is taken with same side foot to
  initiate throw
• Stage 4 – step is taken with contralateral foot,
  thoracic rotation, arm rotation, elbow extension
  Side arm striking pattern: The
         baseball swing

Stance          Stride
                                         Swing


   Lift front foot   Bat begins moving forward



             Follow-through



  Ball-bat impact
Description of
the baseball
swing

								
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