3 Introduction

3.1 Course Introduction

Welcome to ME200: Orthopaedic Biomechanics


3.1.1 Introductions

  • Please provide a brief introduction of yourself
    • Name
    • Degree in progress
    • Ultimate degree goal
    • Research topic and advisor (if grad student)
    • Professional goals
    • Optionally, an item or two of personal interest
  • Note an online class makes it hard to develop relationships
  • Professional networking is critical to job skill and opportunity growth

3.1.2 Objectives

  • The primary objective of this course is to present current methods for analysis of biomechanical systems that include bone, tendon, ligament, cartilage, and other soft tissue.

  • The relevant mechanics that govern biomechanical systems will be presented including elasticity, beam theory, anisotropic materials, viscoelasticity, and contact.

  • Additionally, prosthetics, orthotics, and other medical devices will be discussed.


3.1.3 Project

The assignment is posted on e-learning


3.1.4 Almost-weekly anatomy quiz (Method TBD)

  • Anatomy is an important part of orthopaedics
  • We must be able to converse with medical personnel
  • Thus, we will have an almost-weekly anatomy quiz
  • The mechanism for doing this is still TBD (due to online-learning and Covid)

You will be assigned to watch a series of videos from AnatomyZone.com

http://anatomyzone.com/tutorials/basics/general-skeleton/

You will be assigned to watch those videos outside of the lecture period. Check elearning for more details.

3.2 Conceptual Overview of Orthopaedic Biomechanics

(Reading assignment: [@Bartel2006] Chapter 1.


3.2.1 The human body as a machine

  • The human body is a machine!
    • A combination of rigid and resistant bodies
      • Bones and the soft tissue associated with them
      • Links are joints which have low friction and transfer large forces
    • Large, precise and imprecise motion
    • Performs useful work

Contrasting humans with most machines

  • Most joints have imprecisely defined motion
    • There is flexibility in the soft tissues (ligaments, muscles)
  • This flexibility leads to coupling between loads and motion:
    • i.e. the motion can effect the loads in ways that do not typically occur in “conventional” machines
    • Changes in force will produce changes in joint motion,
    • Changes in relative position between bones (at joint) will change the forces in the joints
    • “sloppy joint”

Joints, range of motion and, precision

  • Hip joint
    • is more rigidly defined by its bony ball and socket
    • widely varying soft tissue restraint… but less reliance


  • Shoulder joint
    • is very imprecisely defined with its ball and socket
    • widely varying soft tissue restraint…
    • requires more soft-tissue control and precision placement


1

“Osteoporosis is the leading cause of age-related kyphosis, with sarcopenia, or age-related muscle loss, being a secondary cause,” Patel explains.2

  • Skeletal loads vary from person to person and over time in a particular person
  • Aging and disease change skeletal response
  • We are not often concerned about precise loads, stresses, etc,
    • rather we compute approximate loads within a level of uncertainty

  • We seek to describe the fundamental behavior of the system
    • Use engineering methods to understand the effect of damage and disease
    • Predict, understand, and influence the methods and techniques used to restore function

  • The skeleton has an amazing ability to repair damage and adapt to physical demands

3

Non-surgical treatment with a brace. Many humerus fractures can be treated without surgery. The humerus shaft fracture above was successfully treated in a “Sarmiento brace”, which wraps around the upper arm and holds the bone aligned while it heals.4