Activity Analysis of the Upper Extremity and Trunk

Kinesiology Laboratory 6:

1. Presentation of Lower Extremity Exercises

2. Vectors

3. Activity Analysisa. Baseball Swing [Leading Arm]

Today’s Activities

Remember to pay attention and TAKE NOTES

These exercises will be on the FINAL PRACTICAL

Presentations

Force vectors give the magnitude and direction of muscle and joint force needed to move a load. They also have two key components, a point of application and line of action.

• Magnitude (how much force) is designated by the length of the vector

• Direction (of force) is designated by the direction of the arrow

• Point of application is where the force is applied (typically the center of the muscle’s attachment)

• Line of action is the infinite line at which the force is acting.

Vector Analysis

Vector Components

Hamill & Knutzen, 2009

When looking at muscle vectors in two dimensions (i.e. on one plane) it is the result of two components• Horizontal Component:• Stabilizing component: degree of parallel forces

generated on the lever (bone and joint) when the muscles angle of pull is less than 90 degrees.

• Dislocating component: degree of parallel forces generated on the lever (bone and joint) when the muscle's angle of pull is greater than 90 degrees.

• Vertical Component/ Rotary Component: • Force of a muscle contributing to bone's movement

around a joint axis; greatest when muscles angle of pull is perpendicular to bone (i.e. 90 degrees).

2-Dimensional Vectors

1. Begin at the axis

2. Draw the Horizontal component

- Parallel to Lever

- Start at muscle insertion

90˚ all rotary (movement force)

> 90˚ Dislocating (force generated away form joint)

< 90˚ Stabilizing (force generated towards joint)

3. Draw Vertical Component

- Perpendicular to Horizontal Component

- Start at muscle insertion

4. Draw vectors ONLY long enough to make a perpendicular angle to the resultant vector.

Drawing Muscle Vector Components

Start With Resultant Vector

Mark the length of Horizontal Component

Draw Horizontal Component

Draw Vertical Component

Example of Vectors at Different Points of a Bicep Curl

Example of Vectors at Different Points of a Bicep Curl

Lever Review

Lever Review

Lever Review

Lever Review

Lever Review

Lever Review

Break the Baseball Bat Swing into 3 Phases:

1. Wind Up

2. Swing

3. Deceleration

http://www.youtube.com/watch?v=7JSMEOv4dXQ&feature=fvwrel

Activity Analysis

Baseball Swing

Lab Report 6

Readings: TG: pp 311-321, 326-329, 332 (not palpation)

For Next Week