Chapter 17: Moving Objects: Throwing, Striking, and Kicking

Outline

• Sequential Movements

  Joint Action Patterns

  Nature of Force Application

• Principles Relating to Throwing, Striking, and Kicking

  Anatomical Principles

  Mechanical Principles

• Examples of Throwing and Striking

  Analysis of the Overarm Throw

  Analysis of the Forehand Drive in Tennis

• Laboratory Experiences

Objectives

At the conclusion of this chapter, the student should be able to:

1. Classify activities involving sequential throwing, kicking, or striking patterns according to the nature of the force application.

2. Name and discuss anatomical and mechanical factors that apply to representative throwing, kicking, or striking activities.

3. Perform a kinesiological analysis of someone engaging in a sequential throwing, kicking, or striking skill under each of these force application conditions: momentary contact, projection, continuous application.

Sequential Movements

A baseball pitcher throws a baseball across the plate and the batter hits it to center field, an elderly man pitches horseshoes, a young person spikes a volleyball, a student practices driving a golf ball while a college athlete practices punting a football. Once more, as is the case with pushing and pulling, a widely diverse set of activities has a common denominator. Each of these activities involves sequential movement of the body segments resulting in the production of a summated velocity at the end of the chain of segments used. During the summation of velocity, it is important to note that changes are the result of an acceleration imparted through an unbalanced force. The magnitude of the unbalanced force as well as the time over which this force acts will determine the final velocity. This concept of the force and the time over which it acts effecting final velocity is called impulse (Chapter 12). Recall that the change in momentum is equivalent to the product of the force and time over which that force acts. The path produced by the end point of this chain of segments is curvilinear in nature.

Sequential segmental motions are most frequently used to produce high velocities in external objects. Depending on the objective of the skill, speed, distance, or some combination, modifications in the sequential pattern may be made. Greater or fewer numbers of segments may be involved, larger or smaller ranges of motion might be used, and longer or shorter lever lengths may be chosen. Regardless of the modifications, the basic nature of the sequential throwing, striking, or kicking pattern remains the same.

Joint Action Patterns

Broer was the first to call attention to the similarity of movement patterns used in seemingly dissimilar activities such as the baseball pitch, the badminton clear, and the tennis serve (Broer & Zernicke, 1979). Objective evidence of such similarities between throwing and striking activities within each of the three major upper extremity patterns (overarm, sidearm, and underarm) was originally revealed by the Broer and Houtz EMG investigations (1967) and confirmed by Moynes and colleagues (1986).