Short answer

Incorporate age-specific material properties of bone, acknowledging its plastic behavior, when designing medical devices or protective structures.

Field: Final Production
Source: SAE technical papers on CD-ROM/SAE technical paper series (2005)
Method: Experimental Testing
Sample: 117 tests from 6 cadavers
Evidence: Strong effect

Human rib cortical bone demonstrates substantial plastic deformation before failure, with a notable increase in brittleness and reduced strain tolerance as age progresses. This final production research insight is drawn from a 2005 study published in SAE technical papers on CD-ROM/SAE technical paper series. Using Experimental testing with 117 tests from 6 cadavers, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Incorporate age-specific material properties of bone, acknowledging its plastic behavior, when designing medical devices or protective structures.

Study

Final ProductionHigh ImpactStrong effect

Human Rib Cortical Bone Exhibits Significant Plasticity and Age-Related Brittleness

Human rib cortical bone demonstrates substantial plastic deformation before failure, with a notable increase in brittleness and reduced strain tolerance as age progresses.

SAE technical papers on CD-ROM/SAE technical paper series · 2005

Key Findings

01Human rib cortical bone exhibits significant plastic deformation, contributing substantially to its strain energy absorption.
02Bone becomes more brittle with increasing age, characterized by a higher elastic modulus and lower peak strain.
03No significant differences in material properties were found based on rib region or rib level in this study.

Application

Design takeaway

Incorporate age-specific material properties of bone, acknowledging its plastic behavior, when designing medical devices or protective structures.

How to apply

When designing orthopedic implants or bone-anchored prosthetics, consider using materials that can accommodate bone's plastic deformation or select designs that mitigate stress concentrations, especially for older patient populations.

Project actions

01When researching materials for a design project, look for data that reflects the actual behavior of the material under stress, including plastic deformation.
02Consider how material properties might change over the lifespan of a product or user.

Method & Evidence

AimTo characterize the dynamic tensile material properties of human rib cortical bone across different ages and anatomical regions.

MethodExperimental Testing

ProcedureCortical bone coupons were precisely milled from human rib sections and subjected to dynamic tensile loading at a controlled strain rate. Stress-strain curves were generated to determine key material properties such as elastic modulus, yield stress, ultimate stress, and strain energy density.

Sample117 tests from 6 cadavers

ContextBiomedical Engineering, Materials Science, Orthopedics

Variables

IVAge of cadaver, anatomical region of rib, rib level

DVElastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, strain energy density

CVStrain rate, specimen preparation method, testing equipment

Strengths & Limitations

Strengths

+Utilized a controlled dynamic tensile testing method.
+Investigated a range of ages and anatomical locations within the rib cage.

Limitations

The cadavers were from a specific population, and the testing was done under controlled laboratory conditions which may not fully represent real-world scenarios.

Reliability & validity

The study's validity is supported by the use of standardized coupon preparation and controlled testing conditions. Reliability is enhanced by testing a significant number of samples across multiple cadavers.

Think critically

How might the observed age-related changes in bone brittleness influence the design of surgical tools or rehabilitation equipment?

Design Principles

"Material behavior is not static; it varies with age and can exhibit significant non-linear (plastic) characteristics that must be accounted for in design."

Understanding the mechanical properties of bone, particularly its capacity for plastic deformation and how it changes with age, is crucial for designing medical implants, prosthetics, and protective equipment. This knowledge informs material selection and structural design to ensure safety, efficacy, and longevity in biomedical applications.

What This Means for Your Design

This study found that bone in your ribs can bend a lot before it breaks, and it gets stiffer but breaks easier as you get older.

How to use in your project

1.Reference this study when discussing the material properties of bone or similar biological tissues, particularly when justifying material choices or analyzing failure modes in your design project.

Add to My Project

Quick Cite

Paragraph starter

Research indicates that human rib cortical bone exhibits significant plastic deformation, absorbing substantial strain energy before failure. Furthermore, material properties are age-dependent, with older bone becoming more brittle, characterized by increased stiffness and reduced strain tolerance. This understanding is critical for designing biomedical devices that interact with bone, ensuring appropriate mechanical compatibility and safety across diverse patient demographics.

Source

SAE technical papers on CD-ROM/SAE technical paper series

Material Properties of Human Rib Cortical Bone from Dynamic Tension Coupon Testing

journal · 2005

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Questions About This Research

What does the research say about human rib cortical bone exhibits significant plasticity and age-related brittleness?: Incorporate age-specific material properties of bone, acknowledging its plastic behavior, when designing medical devices or protective structures. Evidence: SAE technical papers on CD-ROM/SAE technical paper series (2005).
Why does "Human Rib Cortical Bone Exhibits Significant Plasticity and Age-Related Brittleness" matter for design?: Understanding the mechanical properties of bone, particularly its capacity for plastic deformation and how it changes with age, is crucial for designing medical implants, prosthetics, and protective equipment. This knowledge informs material selection and structural design to ensure safety, efficacy, and longevity in biomedical applications.
How can designers apply this research?: Incorporate age-specific material properties of bone, acknowledging its plastic behavior, when designing medical devices or protective structures.
What were the main findings?: Human rib cortical bone exhibits significant plastic deformation, contributing substantially to its strain energy absorption.. Bone becomes more brittle with increasing age, characterized by a higher elastic modulus and lower peak strain.. No significant differences in material properties were found based on rib region or rib level in this study.
What research method was used?: Experimental Testing with 117 tests from 6 cadavers.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2005 journal from SAE technical papers on CD-ROM/SAE technical paper series.
What should I do differently in my next project?: When designing orthopedic implants or bone-anchored prosthetics, consider using materials that can accommodate bone's plastic deformation or select designs that mitigate stress concentrations, especially for older patient populations.
What are the limitations?: Testing was conducted at a single strain rate, and the study did not explore variations due to sex or specific anatomical locations beyond broad regions.