Activity Analysis of the Upper Extremity and Trunk
1.Presentation of Lower Extremity Exercises 2.Vectors 3.Activity Analysis a.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
Lever Review
Break the Baseball Bat Swing into 3 Phases: 1.Wind Up 2.Swing 3.Deceleration MEOv4dXQ&feature=fvwrel Activity Analysis
Baseball Swing
Lab Report 6 Readings: TG: pp , , 332 (not palpation ) For Next Week