force plates

Week Ten Overview

  • Approaching semester end, currently in week ten.

  • Completed sessions on kinematic analysis:

    • Focused on calculating displacement, velocity, and acceleration.

    • Utilized video analysis and software for digitization.

  • Biomechanics projects:

    • Submission deadlines have passed; some extensions granted.

Upcoming Content

  • New focus: Kinetic analysis (forces assessment).

  • Planned sessions:

    • Theoretical session on force measurement.

    • Practical session to collect data.

  • Revision session next week; will cover data processing from the practical session.

  • Importance of understanding forces in sports science.

Key Readings

  • Interesting readings and an essential article from 2001 to be reviewed.

  • Emphasis on identifying different phases of a vertical jump for data collection.

Practical Session Details

  • Discussing system requirements in the mechanics lab.

  • Understanding of sampling frequency (measures collected per second, in Hz).

  • Differentiating between internal and external forces:

    • Internal forces: generated by muscle contractions.

    • External forces: applied forces interacting with the environment.

Measurement Equipment

  • Usage of force platforms in the biomechanics lab:

    • Several types; essential for measuring forces.

    • Fixed and portable options available:

      • Fixed platforms are used for standard lab measurements.

      • Portable platforms can collect data outside the lab.

  • Notable brands include Kistler, Vertex, and MTI.

Force Platform Types

  • Two main types of force platforms:

    1. Piezoelectric platforms:

      • Use sensitive crystals to detect changes in electric charge.

      • Advantages: high sensitivity to force application changes.

      • Disadvantages: performance can be affected by temperature and humidity; more expensive; may introduce drift in prolonged measurements.

    2. Strain gauge platforms:

      • Measure deformities with pressure for force assessment.

      • Advantages: stable recordings over longer periods, cost-effective.

      • Disadvantages: may less accurately capture sudden force changes.

Recording Frequency Considerations

  • Crisis of measurement recording frequency as a requirement in various activities.

  • Standard frequency for capturing human movements: 1000Hz sufficient for most activities.

Output Data Handling

  • Data output from force platforms:

    • Separate reads for vertical, anterior-posterior, and medial-lateral axes.

    • Calculations such as rate of force development (force/magnitude over time).

    • Impulse calculated as: Force × Time.

Applications in Biomechanics

  • Evaluating force during various physical activities:

    • High-intensity scenarios such as sprinting or gymnastics can produce forces exceeding five body weights.

  • Research applications include:

    • Gait analysis, balance testing, vertical jump assessments, and the implications of different types of footwear on force impacts.

Planning for Data Collection

  • Preparation for data collection and processing in the coming week.

  • Recommendations to review relevant studies and emphasize understanding data processing basics.