Tendons and Ligaments L2: Maturation, ageing, and exercise effects on tendons and ligaments Flashcards
Children _____ do/don’t have same tissue properties as adults. What will that affect?
Don’t
- Need specialized rehab program o Cant be same as adult
Will ageing increase or decrease risk?
Increase
What is maturation of tendons and ligaments?
dramatic increase in mechanical properties of tendon/ligaments (strength, stiffness) (up to skeletal maturity)
What is ageing of tendons and ligaments?
A more gradual decrease in mechanical properties
What is altered mode of failure for tendons and ligaments in children/adolescents?
Avulsion more common in children/adolescents than adults
Asynchronous or synchronous maturation of midsubstance and bone-tendon (or boneligament) junction
Asynchronous
Prior to skeletal maturity, strength of MCL substance > bone-ligament junction failure by _______.
tibial avulsion
After skeletal maturity, what happens?
Maturity failure in ligament substance
What affects maturation of tendon (stiffness)? Tendon stiffness is _____ specific.
- Tendon stiffness is not gender specific
- Tendon stiffness is age specific
- Eg. patella tendon = larger and stiffer than in children o increased collagen fibril diameter o increased cross sectional area
What is Sever’s disease?
- Calcaneal apophysitis – inflammation of growth plate
- Affects children 8-11 years
- Overuse problem – exacerbated by running, jumping (squeeze test)
What is Osgood schlatter disease?
- Tibial tuberosity apophysitis
- Overuse problem – aggravated by jumping or running
- More common in boys (although gender gap reducing with increasing participation by girls in sports)
- Affects boys 13-14 and girls 11-12
There is an imbalance adaptation between muscle and tendon in adolescent athletes. True or false.
True
Non-uniform adaptation of muscle and tendon in young athletes results in inc tendon stress during late adolescence. True or false
True Muscles get stronger but tendon doesn’t get thicker
Which training type helps to even out mismatch between muscle and tendon properties in children? How?
- Increased Tendon stiffness (∼29% )
- Increased Young’s modulus (∼25%)
- Increased electromechanical delay ∼13% for the RT group
Strength training can tendon stiffness in children
What are 3 factors that can affect ageing?
- Diet
- Lifestyle
- Environment
What are 6 effects of age on muscle?
- decreased muscle mass (sarcopenia)
- decreased number and size of muscle fibres –> atrophy
- Conflicting results for proportion of type I &II fibres
- Neuromuscular changes – decreased capacity to detect info (proprioception) and activate muscles (motor units remodel) (eg reflexes)
- Decreased strength can be partly offset by resistance exercise
- In active older adults, biochemical properties of remaining muscle mass are well maintained
80yr trained men have higher peak strength than 20yr untrained men `
Why is there a lack of tissue renewal in Achilles tendons?
- Retained 14C demonstrating very limited tissue turnover
- Tendon core is formed during height growth not renewed thereafter
- Possibly outer tendon may renew and proteins between fibrils may have better turnover
- Muscle 14C levels indicated continuous turnover
self-renewal potential in tendons compared to muscles
What is the effect of age on the Achilles tendon?
Achilles tendon loses stiffness
- Older tendons were 15% more compliant than younger tendons
- decreased contractile force
- decreased rate of force development
- Older adults don’t rupture tendons- don’t reach force required for rupture
What is the effect of age on the Patella tendon?
Exercise training in older adults = increased stiffness of patellar tendons
What is the effect of exercise training on older adults?
- Active participation in exercise tends to lessen the impact of ageing on performance
- decreased age-related loss of muscle mass and bone mineral density
- Neural adaptation (plasticity)
- increased quality of life and health
- decreased falls
- Cannot stop ‘healthy’ biological ageing but can markedly reduce many of the decrements in physical capacity with exercise!
Are there any gender differences for tendon properties (stiffness)?
- Previously thought that males have stiffer tendons than females
- We found that Achilles tendon stiffness is linked to strength but not to gender
- Males tend to be stronger than females
Are there gender differences in ligament properties?
- Female athletes are at a 4 times ↑ risk of sustaining a non-contact ACL injury than males.
Why?
- Increased participation of females in sport (title IX in USA)
- Strength imbalance between quads and hams
- Females have less strength in hamstrings than quads
- Neuromuscular strategy (less hamstrings activation)
- Different mechanical properties (from cadaveric study)
- Males- ↑ elongation
- Female- fail at lower load, less stiff = decreased absorption of energy
Why is it important to be specific with exercise?
No all structures respond the same
Exercise can induce ______ and _____ tendon stiffness
tendon hypertrophy; increase
Effects vary for different _____ and ____ of exercise
types; intensities
- Consider direction of loading
- Consider magnitude of loading
Time course______ for different tissues
varies o Consider de-training effects
What are the 3 effects of load magnitude?
¥ Increase in stiffness, elastic modulus, size of AT only in high magnitude load ¥ Low strain exercise may be insufficient trigger for tendon adaptation ¥ Goldilocks zone o Not too low, high o Adaptation without injury
What are the effects of duration in older adults?
¥ Increase in stiffness, modulus, size of AT only in high magnitude load after 14 weeks ¥ No further improvement after 1.5 years
Achilles tendon _____ (increases/decreases) strain (and force) with added mass from jumping training protocols
Increase Type of exercise matters
Patellar tendon _____ (increases/decreases) strain (and force) with added mass from jumping training protocols
Decrease Type of exercise matters
Tendon stiffness adapts ____ (quicker/slower) to training than muscle strength
slower
Tendon stiffness detrains ____ (quicker/slower) than muscle strength
Quicker
Imbalanced periods of adaptation may contribute to ______.
tendon injury
What are the 3 effects of detraining on tendon?
- Moderate exercise exerts a protective effect on the patellar tendon structure
- Sudden discontinuation of physical activity has a negative effect on tendons
- Detrained group had ‘unhealthier’ tendons than the untrained
- After a period of sudden detraining, physical activity should be restarted with caution and with appropriate rehabilitation programs.
After a period of sudden detraining, physical activity should be restarted with ______ and with __________.
caution; appropriate rehabilitation programs
What are effects of exercise type on tendon?
What is needed for adaptation of tendon mechanical properties?
- High loads
- High tendon strains
- If isometric, be performed at long muscle lengths
- Be performed consistently for at least 8 weeks (up to 12-14 w)
What is mechanotransduction?
Turning movement into tissue healing
How precisely does exercise promote tissue adaptation? (3)
- The mechanical trigger
- Communication throughout the tissue to distribute the loading message
- Tissue factory (produces /assembles tissue)
- Cell signaling at each stage enables this process
