Introduction to Biomechanics

INTRODUCTION TO BIOMECHANICS

Course Information

  • Course Code: HES 346
  • Instructor: Garcia

LECTURE OUTLINE

  1. Kinesiology
  2. Biomechanics and its sub-branches
  3. Ways to describe and study movement
  4. Anatomical Position and Reference Terms
  5. Planes and Axes
  6. Joint Motions
  7. Mechanics
  8. Quantities
  9. Application

KINESIOLOGY

  • Definition: Study of human movement
  • Related disciplines:
    • Anatomy and Physiology
    • Biomechanics
    • Exercise Physiology
    • Motor Control

BIOMECHANICS

Definition

  • Combination of biology and mechanics
  • Study of actions of forces
  • Focuses on internal muscle forces and external forces acting on the body

Detailed Definition

  • “The study of forces acting on and generated within a body and of the effects of these forces on the tissues, fluids or materials used for diagnosis, treatment or research purposes.” (Source: European Society of Biomechanics)

WHY STUDY BIOMECHANICS?

  • Reasons for studying biomechanics include:
    • Performance Improvement
    • Technique Improvement
    • Equipment Improvement
    • Training Improvement
    • Injury Prevention and Rehabilitation

Movement Characteristics

  • Effective movement should be:
    1. Safe
    2. Effective
    3. Efficient

APPLICATION OF BIOMECHANICS

  • Understanding movement is essential for teaching it.
  • One must explain the WHY and HOW, not just the WHAT.
  • Importance in foundational courses leading to Applied Biomechanics and graduate studies.

INTRODUCTION TO ANATOMICAL POSITION

Anatomical Position

  • Standard reference position used in anatomical terminology.

Anatomical Reference Points

  • Terms include:
    • Superior: above another structure
    • Inferior: below another structure
    • Anterior: front aspect of the body
    • Posterior: back aspect of the body
    • Medial: closer to the midline of the body
    • Lateral: farther from the midline of the body
    • Proximal: closer to the trunk of the body
    • Distal: farther from the trunk of the body
    • Superficial: near the surface of the body
    • Deep: away from the surface of the body
    • Contralateral: opposite side of the body
    • Ipsilateral: same side of the body

CARDINAL PLANES AND AXES OF MOVEMENT

Axes of Movement

  1. Mediolateral Axis
  2. Vertical/Longitudinal Axis
  3. Anteroposterior Axis

Planes of Movement

  1. Transverse Plane
  2. Sagittal Plane
  3. Frontal/Coronal Plane

JOINT MOTIONS

Basic Movements

  • Flexion and Extension
  • Abduction and Adduction
  • Internal and External Rotation

Specialized Movements

  • Lateral Flexion
  • Elevation and Depression
  • Protraction and Retraction
  • Upward and Downward Rotation
  • Horizontal Abduction and Adduction
  • Plantar Flexion and Dorsiflexion
  • Inversion and Eversion
  • Supination and Pronation
  • Radial and Ulnar Deviation
  • Circumduction

JOINT ACTIONS

Flexion and Extension

Abduction and Adduction

Internal and External Rotation

  • Medial Rotation: rotation towards the midline
  • Lateral Rotation: rotation away from the midline

Lateral Flexion

  • Lateral Flexion (Right)
  • Lateral Flexion (Left)

Elevation and Depression

Protraction and Retraction

  • Protraction: moving forward
  • Retraction: moving backward

Upward and Downward Rotation

  • Downward Rotation: returning to anatomical position
  • Upward Rotation: moving away from anatomical position

Horizontal Abduction and Adduction

Dorsiflexion and Plantar Flexion

Inversion and Eversion

Supination and Pronation

Radial and Ulnar Deviation

Circumduction

MECHANICS

Types of Mechanics

  1. Rigid Body Mechanics
  2. Deformable Body Mechanics
  3. Fluid Mechanics

Rigid Body Mechanics

  • Subfields:
    • Statics: study of bodies at rest
    • Dynamics: study of bodies in motion
    • Kinetics: study of forces causing motion
    • Kinematics: study of motion without regard to forces

QUALITATIVE VS QUANTITATIVE STUDY OF MOVEMENT

Qualitative

  • Describing movement in non-numerical terms

Quantitative

  • Describing movement in numerical terms
    • Example: Describing a vertical jump
  • Qualitative vs Quantitative Comparison

QUANTITIES USED TO DESCRIBE MOVEMENT

Scalar vs Vector Quantities

  • Scalar: A single quantity described purely by magnitude (e.g. mass)
  • Vector: A double quantity possessing both magnitude and direction (e.g. force)

Base vs Derived Quantities

  • Base Quantities: Fundamental units (e.g. length, mass) that cannot be expressed in terms of other quantities
  • Derived Quantities: Quantities calculated from combinations of base quantities (e.g. velocity = distance/time)

MINI CHECK

Identify Qualitative vs Quantitative Statements

  • Qualitative:
    • “Throwing involves glenohumeral abduction and external rotation.”
  • Quantitative:
    • “The ideal range of motion for cervical rotation is 80 degrees.”
    • “Gravity acts in a downward direction.”
    • “Top speed for an elite sprinter is 27.78 mph.”

Identify Scalar vs Vector Quantities

  • Scalar:
    • Mass
    • Volume
  • Vector:
    • Weight
    • Force