Lecture 13 Flashcards
Best way to measure muscle mass - which technique
Cross sectional cut of the thigh
Which muscles can change faster? Big or small muscles?
Bigger muscles change faster
Why does muscle mass matter? (7 factors)
Strength and functionality
Metabolism
Bone health
Insulin sensitivity
Functional independence
Hormonal balance
Longetivity
Why does having more muscle affect the risk of diabetes?
Having more muscle = reducing the risk because more muscles can utilize glucose
Why does muscle mass impact the functionality in older adult?
Reduces the risk of fall (more stability)
How does muscle mass affect bone density?
Increase in mechanical stress (pulling on the bone from the muscle) done through physical activity
What is cachexia?
Loss of body weight and muscle mass, and weakness.
Rate of cachexia after the age of 45 years old
0.8
Rate of cachexia after the age of 65 years old
1.5
Can we stop cachexia?
No, maybe slow it down
Muscle mass matters… (6 things)
- Reduced severity of Alzheimer’s disease
- Reduced ventilation time and length of stay in ICU
- Reduced risk of complications for patients after surgery
- Better response to cancer tx
- Better respiratory parameters in COPD
- Higher survival rate for patients after trauma
True or false? Muscle hypertrophy is much faster than muscle atrophy?
FALSE
Takes 3 days of bedrest to start loosing muscle mass vs 6-8 weeks to gain
How much time does it take to start loosing muscle mass if you are in bedrest?
3 days
Relationship between MPB and MPS
Inverse
What is MPB
Muscle protein breakdown
What is MPS
Muscle protein synthesis
Skeletal muscle serves many purposes: name 6
- Producing movement
- Sustaining body posture and position
- Maintaining body temperature
- Storing nutrients
- Stabilizing joints
Skeletal muscle is to contract in response to what
To contract in response to a stimulus
Most skeletal muscle contraction are under _____ control
Voluntary control, receiving neural inputs allowing conscious control of muscles
What happens when you roll your ankle because you thought there were only 3 steps in the stairs so you miss the last one?
Need to send a specific muscle to contract the muscle so if there is none, you fall
3 types of muscle
Cardiac muscle
Skeletal muscle
Smooth muscle
Which type of sports have the biggest hypertrophied heart?
Explosive sports, because of the overwork from the heart
Skeletal muscle contains ___ to ___ of all body proteins
50-75%
Skeletal muscle comprises approximately ___ of the human bodyweight
40%
When do micro tears in the muscle happen?
When the actin-myosin are detached but we still contract (example: eccentric)
What is DOMS
Delayed onset muscle soreness
What type of contraction is responsible for DOMS?
Eccentric - creates more damage to the muscles
Which creates more pain - going up or down the hill? Why
When going DOWNHILL - because it is eccentric contractions that hold the movement = more damage
In terms of energy cost, which is more demanding? Going up or down the hill?
GOING UP - double the energy cost to get to the top
Oxidative stress is a balance between what 2 things?
Antioxidants and free radicals
What happens when there is oxidative damage?
More free radicals than antioxidants
Oxidative damage leads to 2 things
Tissue injury and inflammation
Are DOMS actually bad?
No correct answer
Is inflammation good or bad?
It may be needed for the recovery process but not proved to be good or bad
How does a patient with DOMS presents in clinical setting? (3)
More swelling
More soreness
Less ROM
How do I measure recovery?
Swelling - circumference
Soreness - questionnaires/scale
ROM - testing
What is the problem with circumference?
Hard to get the exact same spot every time - reproductibilité
What is the Algometer?
Records how much pressure you used to determine the level of pain (to measure deep pressure pain thresholds or tenderness resistance)
True or false? Muscle mass is equal to more muscle strength?
FALSE - muscle mass is not functional
Does muscle strength change the same way as muscle mass when having a bedrest?
No, but it correlates more in younger population than older
How to measure specific muscles?
Machines/hand grip dynamometer/muscle endurance
What food can be used to decrease the DOMS following eccentric exercise?
Curcuma
What food can be used to decrease muscle swelling?
Quercetin
Are curcuma and quercetin proven to be effective?
Not with a final answer
DOMS - indirect markers
Decrease muscle strength
1RM
Handgrip strength and endurance
DOMS - indirect markers
Increase muscle pain
Algometer pressure pain threshold
DOMS - indirect markers
Increase stiffness
Goniometer ROM
DOMS - indirect markers
increase swelling
Muscle circumference
DOMS - indirect markers
decrease perception of wellness
Questionnaire on wellness (sleep, fatigue, soreness)
Soreness can also come from very basic movements, why?
Co-contraction from new and complex movements so other muscles contract = higher demand on the body
