QUEEN MARY UNIVERSITY OF
LONDON
TENDON STRUCTURE-FUNCTION
RELATIONSHIPS REPORT
EMS618U – Cell and Tissue Mechanics
, Abstract
Tendons, specialised tissues that connect muscles to bones, are crucial for transmitting force and facilitating
movement. Their functionality hinges on their unique mechanical attributes, which are explored through an
experimental comparison of rat tail tendon explants subjected to di=erent storage methods before testing. The
study hypothesises that storage conditions—specifically, incubation in phosphate-bu=ered saline (PBS) versus
immediate freezing—significantly a=ect tendons' mechanical behaviour, observable in stress relaxation and
stretch-to-failure tests. The experimental methodology involved dissecting tendon explants and storing
them via two distinct methods: incubation in PBS for a week followed by freezing, and immediate freezing.
These samples underwent mechanical testing, including stress relaxation and stretch to failure, using an
Instron Machine. Calculated metrics included tangent modulus, relaxation percentage, relaxation modulus,
and relaxation time, o=ers insights into the tendons' mechanical responses under di=erent conditions.
Results from stress relaxation and stretch-to-failure tests indicated notable di=erences between fresh
and incubated tendons. Fresh tendons demonstrated higher initial stress and maintained greater stress levels
throughout the tests, suggesting superior mechanical integrity compared to their incubated counterparts. This
di=erence implies that the incubation process might alter the tendon's collagen and proteoglycan content,
thereby a=ecting its strength and elasticity. Stress-strain graphs further highlighted that fresh tendons could
sustain higher stress for a given strain before relaxation, indicative of a sti=er material.
Table of Contents
Abstract ................................................................................................................................. 1
Introduction ........................................................................................................................... 2
1. Definition of a Tendon .......................................................................................................... 2
2. Tendon Structure..................................................................................................................... 2
2.1. Composition of Tendon ..................................................................................................... 2
2.2. Hierarchal organisation of Tendon...................................................................................... 2
3. Mechanical Properties of Tendon ............................................................................................. 3
3.1. Tensile Strength ................................................................................................................ 3
3.2. Viscoelasticity .................................................................................................................. 3
3.3. Non – Linear Elasticity ....................................................................................................... 3
4. Hypothesis .......................................................................................................................... 4
Methods................................................................................................................................. 4
Method followed in the laboratory session: .................................................................................. 4
Calculated quantities: ................................................................................................................ 4
Tangent modulus..................................................................................................................... 5
Relaxation percentage ............................................................................................................. 5
Relaxation modulus ................................................................................................................ 5
Relaxation time ....................................................................................................................... 5
Results .................................................................................................................................. 6
Stress Relaxation Graphs ......................................................................................................... 6
Stress to Failure Graphs........................................................................................................... 7
Discussion ............................................................................................................................. 8
Stress Relaxation. ................................................................................................................... 8
Comparing of log graphs: ......................................................................................................... 9
Stretch to failure first graph: ..................................................................................................... 9
LONDON
TENDON STRUCTURE-FUNCTION
RELATIONSHIPS REPORT
EMS618U – Cell and Tissue Mechanics
, Abstract
Tendons, specialised tissues that connect muscles to bones, are crucial for transmitting force and facilitating
movement. Their functionality hinges on their unique mechanical attributes, which are explored through an
experimental comparison of rat tail tendon explants subjected to di=erent storage methods before testing. The
study hypothesises that storage conditions—specifically, incubation in phosphate-bu=ered saline (PBS) versus
immediate freezing—significantly a=ect tendons' mechanical behaviour, observable in stress relaxation and
stretch-to-failure tests. The experimental methodology involved dissecting tendon explants and storing
them via two distinct methods: incubation in PBS for a week followed by freezing, and immediate freezing.
These samples underwent mechanical testing, including stress relaxation and stretch to failure, using an
Instron Machine. Calculated metrics included tangent modulus, relaxation percentage, relaxation modulus,
and relaxation time, o=ers insights into the tendons' mechanical responses under di=erent conditions.
Results from stress relaxation and stretch-to-failure tests indicated notable di=erences between fresh
and incubated tendons. Fresh tendons demonstrated higher initial stress and maintained greater stress levels
throughout the tests, suggesting superior mechanical integrity compared to their incubated counterparts. This
di=erence implies that the incubation process might alter the tendon's collagen and proteoglycan content,
thereby a=ecting its strength and elasticity. Stress-strain graphs further highlighted that fresh tendons could
sustain higher stress for a given strain before relaxation, indicative of a sti=er material.
Table of Contents
Abstract ................................................................................................................................. 1
Introduction ........................................................................................................................... 2
1. Definition of a Tendon .......................................................................................................... 2
2. Tendon Structure..................................................................................................................... 2
2.1. Composition of Tendon ..................................................................................................... 2
2.2. Hierarchal organisation of Tendon...................................................................................... 2
3. Mechanical Properties of Tendon ............................................................................................. 3
3.1. Tensile Strength ................................................................................................................ 3
3.2. Viscoelasticity .................................................................................................................. 3
3.3. Non – Linear Elasticity ....................................................................................................... 3
4. Hypothesis .......................................................................................................................... 4
Methods................................................................................................................................. 4
Method followed in the laboratory session: .................................................................................. 4
Calculated quantities: ................................................................................................................ 4
Tangent modulus..................................................................................................................... 5
Relaxation percentage ............................................................................................................. 5
Relaxation modulus ................................................................................................................ 5
Relaxation time ....................................................................................................................... 5
Results .................................................................................................................................. 6
Stress Relaxation Graphs ......................................................................................................... 6
Stress to Failure Graphs........................................................................................................... 7
Discussion ............................................................................................................................. 8
Stress Relaxation. ................................................................................................................... 8
Comparing of log graphs: ......................................................................................................... 9
Stretch to failure first graph: ..................................................................................................... 9
