Strength and Flexibility

Question 1

What are strenfght and flexibilty?

Answer 1

Constraints to skilled performacne and everydady activity
Strength is a rate limiting constrain for infants standing
Flexibility is a constraint for many activities
Athletes are best when strong and supple
Training should emphasize a balance

Question 2

What is strength?

Answer 2

The ability to exert force

Depends on number and size of fibres that are neurologically activated

Question 3

How is strength assessed?

Answer 3

Force exerted against resistance
-Isotonic
-Isokinetic
-Isometric
Must specify muscle group, movement, speed and joint angle
1RM
Dynamometer

Question 4

What is taken into consideration during assessment?

Answer 4

The mechanical advantage the fibres gain based on where the force is applied in relation to axis of rotation
Neurologically, strength depends on degree of coordination in activating the fibres
Cannot assume that strength changes as muscle mass changes
Growth follows a sigmoid pattern
Force exertion depends on
-cross sectional area
-neurological factors

Question 5

What are functional strength tests?

Answer 5

Chin up
flexed arm hang
Rope climbing
Body weight is used as resistance
Often require skill which affects test performance

Question 6

What are developmental changes in strength for preadolescents?

Answer 6

Strength increases as children grow
boys and girls are similar until 13
Wood measured muscular strength and determined largest constributer was cross-sectional area
Strength increases steadily with growth

Question 7

What was Asmussen and Heeboll-Nielson’s study?

Answer 7

Boys of same height into 2 age groups
Older group showed greater arm and leg strength (5-10% /yr)
Strength is not related to muscle size alone, there are neurological factors at play
Measured vertical jump and sprint
Practice aided performance

Question 8

What are the neural factors that likely exert influence?

Answer 8

Myelination of nerve fibres
Muscle coordination
Relaxation of opposite muscles
Increase motor unit activation

Question 9

What were the conclusions of Asmussen and Heebol-Nieson’s study?

Answer 9

FUnctional strength increases at faster rate than anticipated by muscle growth which emphasizes neurological growth
Peak strength increase follow peak muscle increase
Among same-size children of different ages, more mature children are stronger

Question 10

What does strength look like in adolescence and young adulthood?

Answer 10

Clear general trend is that males demonstrate greater strength then women in adolescences
Boys gain more muscle mass
The average adult male is stronger than the average adult female
Women only produce 60-80% of the force
Other factors may account for the differences

Question 11

What did shepard’s study show?

Answer 11

Over a period of 3 visits females improved on each subsequent visit, whereas males didn’t

Question 12

What is habitual physical activity?

Answer 12

Traditional physical activity for boys promote strength development more than girls

Question 13

How does muscle finer composition affect strength in adolescence and young adulthood?

Answer 13

Differnece in muscle fiber composition in boys and girls
Davies found no gender relationship between strength and muscle fiber composition
Males are generally stronger, especially in the arms and shoulders due to greater muscular hypertrophy

Question 14

What iare strength changes after cessation in growth?

Answer 14

After growth stops, increases in muscle mass are associated with resistance training
Culturally this is an activity more acceptable for males

Question 15

What does strength look like in middle and older adulthood?

Answer 15

Generally maintained in 20s and 30s
Generally declines after 30sGradual at first
After 50s 18-20% loss
Gardner reported a 45% loss of strength after 65

Question 16

What are additional factors of strength in middle and older adulthood?

Answer 16

Young found 39% loss of strength but only 25% loss in cross-sectional area in quads
Loss of muscle mass does not parallel loss of strength
Changes in muscle fibers (shrinking of type II)
loss of motor neurone in spinal cord
Reduction in number of capillaries/muscle fibre

Question 17

What are other considerations of adult strength?

Answer 17

Some older adults do not lose strength(effected by exercise)

Difficult to determine if loss of muscle mass and strength in older adults is related to aging of tissues or disuse

Question 18

What is stregnth training consist of?

Answer 18

Prepubescents can increase strength
-increase neurological coordination
-monitored to avoid injury
Adolescents and adults can increase strength and muscle mass with appropriate resistance training

Question 19

What is flexibilty?

Answer 19

Ability to move joints through full ROM
Benefits sport performance
Limited flexibility can be a factor in jury
Joint specific

Question 20

What are ACSM recommendations for flexibility?

Answer 20

1) 2-3 days/wk
2) all major muscle /tendon groups
3) static or PNF
4) 10-30secnds hold
5) 4 repetitions/ muscle group

Question 21

How is flexibility assessed?

Answer 21

Each joint muscle be assessed
Goniometer is used
(axis placed over joint, instrument aligned with limb at extreme movement range)
Sit adn reach is common

Question 22

What are developmental changes in flexibility?

Answer 22

Infants and toddlers are very flexible
Studies shoew flexibilty declines in childhood
Can be maintained or improved
Girls as a group are more flexible
In adolescence flexibility is varianle, some peole lose a significant degree

Question 23

What are changes in sit and reach over age in girls?

Answer 23

Upper % at young age increase

Lower % at young age tends to decrease

Question 24

What does ?flexibility look like in adulthood?

Answer 24

Lose flexibility, especially in the little used joints after 50
Maintain training maintain levels
Each joints has its own ROM

Question 25

What is flexibility training?

Answer 25

Maintain ROM

Improve ROM in those with limited