What Is Biomechanics in IB SEHS?
Biomechanics in SEHS is the study of human movement through mechanical principles. It examines how forces interact with the body to influence performance, posture, and injury.
👉 Get a detailed breakdown with RevisionDojo’s SEHS Topic 4 Notes.
1. Understanding Force and Motion
- Force is a vector quantity—meaning it has both magnitude and direction.
- Contact forces include friction and tension; non-contact forces include gravity.
- These forces initiate or change motion in the body.
Learn how forces act in motion with RevisionDojo’s Biomechanics Practice Tools.
2. Centre of Mass and Stability
The centre of mass (COM) is the average point of mass distribution in the body.
- A wider base of support = more stability.
- A lower COM = more balance.
- When the line of gravity falls outside the base, instability increases.
👉 Test your understanding using RevisionDojo's Topic 4.3 Injury Question Bank.
3. Levers in Human Movement
Levers in the body are formed by bones (bars), joints (fulcrums), and muscles (effort).
- First-class lever: Neck – fulcrum in the middle
- Second-class lever: Ankle – load in the middle
- Third-class lever: Elbow – effort in the middle (most common)
💪 Practice with RevisionDojo’s Lever Flashcards.
4. Motion Types in Sports
- Linear motion: movement in a straight line (e.g., running)
- Angular motion: rotation around a fixed axis (e.g., high jump)
- General motion: a combination of both (e.g., gymnastics)
Explore examples in RevisionDojo’s SEHS New Syllabus Hub.
5. Biomechanics in Performance and Injury
Biomechanics helps:
- Identify risky movement patterns
- Correct form for efficient training
- Reduce stress on joints and muscles
📘 Check the RevisionDojo blog for biomechanics applications in sports science.
Summary Table: Core Concepts
Concept Description Force Push/pull influencing acceleration Centre of Mass Balance point in the body Lever Mechanics Fulcrum-effort-load systems in movement Types of Motion Linear, angular, and general movement Stability Factors Base width, COM height, line of gravity
Frequently Asked Questions (FAQs)
Q1: What makes biomechanics important in sports?
A: It improves technique, power output, and reduces injury risk.
Q2: How does the COM affect gymnastics or dance?
A: Shifting COM enables balance in mid-air or during turns.
Q3: Which lever type gives athletes more range?
A: Third-class levers increase speed and motion range—key in sprinting.
Q4: Why use diagrams when learning biomechanics?
A: Diagrams clarify motion, joint angles, and force application visually.
Q5: Where can I practice biomechanics exam questions?
A: Use RevisionDojo’s Questionbanks for structured revision.
Q6: Can poor biomechanics cause injuries?
A: Yes—misaligned forces and posture lead to joint and muscle strain.
Conclusion and Call to Action
Understanding biomechanics is crucial to interpreting how the body moves in sport. It connects anatomy to motion and provides tools for training smartly and safely.
🎯 Ready to master IB SEHS biomechanics?
Click here to explore RevisionDojo’s Full SEHS Revision Toolkit, with diagrams, flashcards, and exam tips designed just for you.
