Support and Movement
Unit 14: Biomechanics
Learning Objectives
At the end of this unit, you should be able to:
I. Describe how muscles attach to bones to produce movement.
II. Describe the principle of muscular antagonism in movement, using the forearm as an example.
III. Define the following terms: lever, fulcrum, resistance, effort.
IV. Describe three types of levers and give an example of each type in the human body.
V. Explain the biomechanical principles and functioning of a lever system.
Learning Objectives and Guiding Questions
At the end of this unit, you should be able to complete all the following tasks, including answering the guiding questions associated with each task.
I. Describe how muscles attach to bones to produce movement.
- Use one complete sentence to describe the function of a tendon (See Unit 6).
- State the specific tissue type of which tendons are composed (See Unit 6).
- Describe the location of and relationship between the origin and the insertion of a muscle, to explain how muscles move bones.
II. Describe the principle of muscular antagonism in movement, using the forearm as an example.
- Define the terms ‘agonist’ and ‘antagonist’ as they pertain to specific movements and muscles.
- Using the elbow joint as a specific example, explain how antagonistic pairs of muscles produce a movement about a joint.
III. Define the following terms: lever, fulcrum, resistance, effort.
- Draw an annotated diagram of a lever system. Your diagram should show where along a lever each major component acts, along with single-sentence definitions for each of these terms:
- Lever
- Fulcrum
- Resistance
- Effort
IV. Describe three types of levers and give an example of each type in the human body.
- Draw annotated diagrams of each of the three classes of levers, showing the major components of a lever system as well as the location where the effort and resistance are applied. Provide one specific example of each class of lever found in the human body.
- Draw an annotated diagram of each of the following movements, describing each as a lever system. Each diagram should include labels identifying the main components (bone, muscle, joint, force), both as part of a lever system (using the terms lever, fulcrum, resistance, effort) and by their correct anatomical name (for bones and muscles).
- Bending the elbow (flexion at the elbow).
- Starting with the head tilted forward, tilt the head upwards (extension of the head).
- Standing on your toes (extension at the ankle).
- Clearly indicate the following on each diagram from the question above:
- The exact location where the resistance is applied to the lever
- The exact location where the effort is applied to the lever
- The resistance arm
- The effort arm
- Draw annotated diagrams to demonstrate whether each of the three classes of levers can be a power lever, a speed lever, both, or neither.
V. Explain the biomechanical principles and functioning of a lever system.
- Using the flexion of the for