Kinesiology/Biomechanics - Final Exam

Deterministic Model

A model that breaks a skill into mechanical cause-and-effect relationships to explain performance.

(Let’s figure out exactly what helps you jump higher, step by step.)

Purpose of a Deterministic Model

To identify which mechanical factors most influence successful performance of a skill.

(The goal is to get your body high enough to go over the bar. That’s it. Jump high.)

Step 1 of Creating a Deterministic Model

Determine the primary purpose of the skill in mechanical terms.

Primary Mechanical Purpose of the High Jump

Maximize center of gravity (CoG) height to clear the bar.

(What smaller things help with jumping high?

There are three big helpers)

Step 2 of Creating a Deterministic Model

Analyze cause-and-effect mechanical relationships to identify subgoals.

(The harder and longer you push, the higher you go.)

Step 3 of Creating a Deterministic Model

Identify mechanical and technique contributions to each subgoal.

Subgoal 1 of High Jump Deterministic Model

Maximize CoG position at takeoff.

(Start the jump as tall as possible - Stand up straight, Stretch your leg, Reach your arms up, Lift your free leg, Be super tall

Mechanical Contributors to Subgoal 1

Upright posture, full extension of takeoff leg, arms raised, free leg raised, tall body position.

(Run fast before the jump, Take a quick last step, Bend a little, then push up, Swing your arms and leg up

Subgoal 2 of High Jump Deterministic Model

Maximize vertical velocity of CoG at takeoff.

(Lean back, Curve your body, Let your arms and legs hang over)

Mechanical Contributors to Subgoal 2

Fast run-up, quick last step, low CoG at start of takeoff, long takeoff contact time, strong upward arm and free leg acceleration.

Subgoal 3 of High Jump Deterministic Model

Minimize the difference between maximum CoG height and bar height.

Mechanical Contributors to Subgoal 3

Lying back over the bar, arched/draped body position, long limbs clearing the bar.

The big idea

A deterministic model just: figures out the main goal, breaks it into smaller goals, explains what your body should do to help each one

Rapid Accelerations in Movement Analysis

Very fast changes in speed or direction during a movement.

Extreme Range of Motion (ROM)

When a joint moves close to its maximum possible angle.

Why Are Rapid Accelerations Important to Identify?

They increase forces on the body and raise the risk of injury.

Why Are Extreme ROMs Important to Identify?

They place high stress on joints, muscles, and connective tissue.

Importance of Identifying Rapid Accelerations and Extreme ROMs

They show where the highest forces and injury risks occur in a movement.

What Do Rapid Accelerations and Extreme ROMs Indicate in Analysis?

Critical moments where technique, performance, and injury risk are most affected.

Practical Use of Identifying Rapid Accelerations and ROM

Helps improve technique, prevent injury, and target coaching or training corrections

Plane of Movement

The direction a movement happens in (sagittal, frontal, or transverse).

Observation Line of Sight

The direction the observer views the movement from.

Relationship Between Line of Sight and Plane of Movement

The observer's line of sight should be perpendicular to the plane of movement.

Why Must Line of Sight Be Perpendicular to the Plane of Movement?

To accurately see joint motion, angles, and timing without distortion.

What Happens If Line of Sight Is Parallel to the Plane of Movement?

Movement appears distorted and important motion may be missed.

Example of Correct Line of Sight

To analyze sagittal plane motion, observe from the side.

Importance in Movement Analysis

Proper line of sight allows accurate assessment of technique and mechanics.