Biomechanical engineers investigated how the initial knee flexion angle affects the peak vertical ground reaction force generated by athletes during a countermovement jump on a stationary force plate. In the experiment, athletes performed jumps starting from pre-determined knee flexion angles (30°, 45°, 60°, and 75°), while force plate sensors continuously recorded the maximum force exerted against the platform during takeoff. All trials were conducted using the same athlete cohort wearing identical athletic footwear under standardized indoor temperature and humidity conditions. Based on this experimental design, match each experimental component to its corresponding variable classification.
- Initial knee flexion angle (30°, 45°, 60°, 75°)Independent Variable
- Peak vertical ground reaction force recorded by the force plateDependent Variable
- Athletic footwear and indoor environment parametersControlled Variable
Answer
The initial knee flexion angle is the independent variable, the peak vertical ground reaction force is the dependent variable, and the athletic footwear and indoor environment parameters are controlled variables.
The initial knee flexion angle is the independent variable because researchers systematically set it to specific angles (30°, 45°, 60°, 75°). The peak vertical ground reaction force is the dependent variable because it is the outcome measured by the force plate. The athletic footwear and environment parameters are controlled variables because they are held constant across all trials to isolate the relationship between knee angle and force production.
Step-by-Step Solution
Key Concept
Identifying Independent, Dependent, and Controlled Variables
Estimated Time:1m 30s