Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy > Tendons > Flashcards

Tendons Flashcards

1
Q

Tissue composition of tendons and ligaments

A

Dense connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Toe region relevant to tendons/ligaments

A

Means that they can be flexible first to allow movement but then stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Tendon function

A
  • Store, absorb and release energy (save energy), Achilles and patella
  • Power amplification (stretch to store then release)
  • Protect the muscle from damage but acting as a shock absorber
  • Transmit force from muscle to bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Energy storage tendons

A

Energy storage tendons have increased elasticity and fatigue resistance (most fail at 8%, Achilles strains at >12). Achilles is the best at this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Energy buffering/amplifying

A

Buffer - Tendon lengths before muscle to precent eccentric damage (walking down hill or landing from jump)

Amplifying - Achilles slowly stores then quickly releases for more power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Achilles’ tendon fascicle alignment

A

Fascicles spiral 90 degrees during decent

  • LG and soleus insert onto calcaneus with strong torsion
  • MG fairly parallel

Important for strain distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Tendon stiffness calculation

A

Stiffness (k) can be calculated from tendon strain and ankle joint torque (strain gauge)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

ITB

A

Important in energy storage, particularly during running (7J). Common overuse injury for running.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the electro-mechanical delay

A

A tendon that has increased compliance will require more muscle contraction before force can be generate around a joint. The tendon is taking the slack before force on bone.

This means there is a delay between muscle activation and production of force which is referred to as the electro-mechanical delay. ⬆️ compliance = greater electro-mechanical delay, less force transmitted for given change in length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Aponeurosis

A

Broad sheet of dense regular connective tissue, attaches muscle to bone or muscle to muscles or muscle to fascia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Enthesis

A
  • Enthesis - insertion region for tendon/ligament onto bone
    • Aids in load transfer between the elastic tendon and the rigid bone (100x stiffer than tendon/ligament)
    • Fibrous - directly onto bone
    • Fibrocartilaginous - 4 zones with a gradual transition
    • Muscular - attachment of muscle without tendon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Muscular tendon junction

A
  • Abrupt rather than gradual transition
  • Collagen fibers and muscle fibers interdigitate, this increases SA for force transmission and therefore decreases stress
  • Less relevant for proximal muscle as they have fleshy attachments meaning their CSA will already be high
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Structures surrounding tendons

A
  • Fibrous sheath/retinacula (hand), assist in joint stability
  • Synovial sheath and peritendinous fluid, reduce friction
  • Bursae, reduce compression on tendon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tendon vs ligament composition

A

Both have similar fibroblast to ECM ratio (10-20%:80-90%)

Ligament mainly collagen type 1 with some 3,4 and 5. Tendon mainly type 1 (stronger) less type 3.

Ligament has varying amounts of elastin while tendons have small amount

Ligaments have varied collagen arrangement (resist force in multiple direction) Tendons have collagen aligned along long axis (anisotropic, loading direct is important)

Tendons can have proteoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Difference in stress strain curves

A
  • Failure mode differs with tendons failing abruptly and ligaments failing progressively, due to fiber orientation.
  • Tendons have a smaller toe region, easier to uncrimp as all in one direction.
  • Tendons have smaller elastic regions (higher gradient) because of lower elastin, results in increased stiffness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Toe region

A

due to crimp of relaxed collagen fibrils, large strain for little stress.

17
Q

Rate and time dependent properties of tendons and ligaments

A

Because they are viscoelastic

  • Creep
    • Fixed force length will gradually increases until unloading (recovery non linear. Bad posture
  • Stress relaxation
    • Strain is constant the stress will decay over time. Change position of splints or boots
  • Hysteresis
    • Tissue loading and unloading will cause some energy to be load through heat. More compliant over time
  • Loading rate
    • Low loading rates - avulsion fracture more common
    • High loading rates - mid substance tear more common
  • Temperature
    • High temperatures increases stress relaxation and creep (heat for more complience)
18
Q

Maturation vs ageing

A

Maturation - occurs quickly, dramatic increases in mechanical properties of tendons and ligaments (strength, stiffness). Stops at skeletal maturity. Altered mode of failure (avulsion in younger)

Ageing - more gradual decrease in mechanical properties

19
Q

Maturation

A

Patella tendon in adults is larger and stiffness than children, due to increased collagen fibril diameter and CSA

Stiffness did not different between gender

Asynchronous maturation of mid substance and bone-tendon/bone-ligament junction

Before skeletal maturity tendon/ligament substance has greater strength than bone-ligament junction which causes avulsion. After mature than failure in substance

20
Q

Severes disease

A

Also referred to as calcaneal apophysitis

Inflammation of growth plate of calcaneus (tendon attachment)

Children 8-11

Overuse problem (running, jump)

21
Q

Osgood Schlatter disease

A

Tibial tuberosity apophysitis

Overuse (jumping running)

More common in boys (could be because of sport participation)

Boys 13-14, girls 11-12

22
Q

Tendon and muscle imbalance for adaptation

A

Non uniform adaptation of muscle and tendon in young athletes leads to increase tendon stress (less CSA tendon, increasing muscle strength) during late adolescence

Muscles get stronger and tendon doesn’t get thicker

Strength training can help to limit this imbalance by increasing tendon stiffness

23
Q

Ageing in tendon

A

Very limited self renewal potential in tendons when compared to muscle

Tendons become less stiff (more compliant) with age. Muscle tend to become more stiff to counter this.

Found that increased exercise for patella tendon increased stiffness in older adults. Cannot stop ageing but can markedly reduce negatives.

24
Q

Exercise effects on tendon

A

Can induce hypertrophy and therefore increased tendon stiffness. Effects vary based on intensity and type of exercise.

Need high magnitude loading (high tendon strain) for increase stiffness, elastic modulus and size

Isometric → Concentric → eccentric

Perform consistently for at least 8 weeks

Type of exercise and specific tendon matter

Counter movement jumps to max height with increasing mass found:

  • Achilles tendon increases strain with mass
  • Patellar tendon decrease strain with mass
25
Q

Detraining

A

Sudden discontinuation of physical activity

Detrain groups have unhealthier tendon than untrained groups.

26
Q

Ligament healing stages

A

Continuous process with 3 overlapping phases:

  • Inflammation (some haemorrhaging)
  • Proliferation - adding new (scar tissue)
  • Remodelling - turning over of scar tissue
27
Q

Ligament healing process

A

10 days - defect filled with vascular inflammatory tissue

3 wks - inflammatory cells subside and active fibroblasts dominated (new tissue generation)

6 wks - decrease in number and size of fibroblast, evidence of longitudinal alignment of nuclei (long axis of ligament)

14 wks - remodelling, increased realignment and decreased cell numbers

14-40 wks - few changes noted, cells re aligned larger and more numerous

Increased CSA throughout to counter weakness (decreased from 3-14), however laxity is actually increased (less effective)

28
Q

Mechanical properties of healed ligament

A

Decreased stiffness, decreased load at failure, altered site of failure (entire ligament is weaken so mid substance failures become more common, not just insertional)

Healed ligaments are more bulky (CSA) but not as strong

29
Q

Tendon injury MOI

A
  • Excessive force (acute)
  • Repeated overload (hysteresis, loading curves change over time)
  • Normal force applied to weaker tendon (after detraining)
  • Stress shielding
    • Even if normal forces applied, some fibres in tendon may be underloaded (stress shielded) while others are overloaded
    • Walking in repetitive supination = more load on lateral fibers
  • Force applied in alternative direction
    • Compression often contributes to tendinopathy (Achilles or glute Medius)
30
Q

Other factors effecting tendon pathology

A

Other factors include ageing, obesity, physical activity levels, disease, medication, alcohol (inhibits fibroblast proliferation)

31
Q

Tendon pathology

A
  • Overuse tendinopathy - Can occur in mid substance, insertion or musculotendon junction
    • Disorganised collagen, more vascularised, more cells, increased proteoglycans and water content
  • Reduced stiffness in Achilles but increased stiffness in patella
  • Paratendinitis - tendon rubs over bony protuberance
    • Inflammatory response (not in tendon), can cause crepitus
  • Tendon rupture - mostly occurs in tendon weakened by pre existing degenerative change (diabetes, alcohol) but can occur in normal tendon in load sufficient
    • Common in rotator cuff and Achilles

Assess pathology through composition, structure (CSA) and function

32
Q

Rehab and immobilisation for tendons

A

Rehab for tendinopathy

Exercise is critical, controlled loading (isometric). Progressive loading to remodel tendon. Avoid compressive loading (especially if insertional)

Healing is slow (hypocellular ect)

Insertion sites more resistant to recovery

Immobilisation

Few weeks can lead to decreased structural properties (weaker, disorganised collagen)

Anatomy (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions