Ch. 4 Biomechanics of Resistance Exercise

Question 1

anatomy

Answer 1

encompasses the study of components that make up the musculoskeletal “machine”

Question 2

biomechanics

Answer 2

focuses on the mechanisms through which these components interact to create movement

Question 3

axial skeleton

Answer 3

consists of the skull, vertebral column, ribs, and sternum

Question 4

appendicular skeleton

Answer 4

includes the shoulder (or pectoral) girdle (left and right scapula and clavicle); bones of the arms, wrists, and hands (left and right humerus, radius, ulna, carpals, metacarpals, and phalanges); the pelvic girdle (left and right coxal or innominate bones); and the bones of the lys, ankles, and feet (left and right femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges)

Question 5

joints

Answer 5

the junctions of bones

Question 6

fibrous joints

Answer 6

allow virtually no movement, (structures of the skill)

Question 7

cartilaginous joints

Answer 7

allow limited movement (intervertebral disks)

Question 8

synovial joints

Answer 8

allow considerable movement (elbow and knee)

Question 9

hyaline cartilage

Answer 9

covers bone ends

Question 10

synovial fluid

Answer 10

fills the capsule that encloses the entire joint

Question 11

Uniaxial joints

Answer 11

operate as hinges (like the elbow)

Question 12

Biaxial joints

Answer 12

allow movement around to axes (wrists, ankles)

Question 13

Multiaxial joints

Answer 13

allow movement about all three perpendicular axes (shoulder and hip)

Question 14

vertebral column

Answer 14

made up of several vertebral bones separated by flexible disks that allow movement to occur

Question 15

vertebrae groupings

Answer 15

cervical vertebrae, thoracic, lumbar, sacral, coccygeal

Question 16

fleshly attachments

Answer 16

most often found at the proximal end of a muscle

Question 17

Fibrous attachments

Answer 17

tendons, they blend into and are continuous with both muscle sheaths and the connective tissue surrounding the bone

Question 18

agonist

Answer 18

the muscle most directly involved in bringing about a movement, AKA prime mover

Question 19

antagonist

Answer 19

a muscle that can slow down or stop the movement

Question 20

synergist

Answer 20

a muscle when it assists indirectly in a movement

Question 21

lever

Answer 21

a rigid or semirigid body that, when subjected to a force whose line of action does not pass through its pivot point, exerts force on any object impeding its tendency to rotate

Question 22

fulcrum

Answer 22

the pivot point of a lever

Question 23

moment arm

Answer 23

the perpendicular distance from the line of action of force to the fulcrum

Question 24

torque

Answer 24

the degree to which a force tends to rotate an object about a specified fulcrum. It is defined quantitatively as the magnitude of a force times the length of its moment arm

Question 25

muscle force

Answer 25

force generated by biomechanics activity, or the stretching of non contractile tissue, that tends to draw the opposite ends of a muscle toward each other

Question 26

resistive force

Answer 26

force generated by a source external to the body that acts contrary to muscle force

Question 27

mechanical advantage

Answer 27

the ratio of the moment arm through which an applies force acts that through which a resistive force acts

Question 28

first-class lever

Answer 28

a lever for which the muscle force and resistive force act on opposite sides of the fulcrum (

Question 29

second-class lever

Answer 29

a lever for which the muscle force and resistive force act on the same side of the fulcrum, with the muscle force acting through a moment arm longer than that through which the restive force acts, (calf muscle to raise leg)

Question 30

third-class lever

Answer 30

a lever for which the muscle force and resistive force act on the same side of the fulcrum, with the muscle force acting thought a moment arm shorter that that throughout which the resistive force acts

Question 31

anatomical position

Answer 31

body erect, the arms are down at the sides, and the palms face forward

Question 32

Three planes of the human body

Answer 32

Sagittal, frontal, and transverse planes

Question 33

acceleration

Answer 33

change in velocity per unit time

Question 34

strength

Answer 34

the maximal force that a muscle of muscle group can generate at a specified velocity

Question 35

power

Answer 35

defined as "the time rate of doing work"

Question 36

work

Answer 36

the product of the force exerted on an object and the distance the object moves in the direction in which the force is exerted

Question 37

weight

Answer 37

the multiplication of the mass of the bar by the local acceleration of gravity

Question 38

angular displacement

Answer 38

the angle through which an object rotates

Question 39

angular velocity

Answer 39

the object's rotational speed, measured in radians per second

Question 40

rotational work

Answer 40

=torque x angular displacement

Question 41

recruitment

Answer 41

getting motor units involved in muscle contraction

Question 42

rate coding

Answer 42

the rate at which the motor units are fired

Question 43

pennate muscle

Answer 43

fibers that align obliquely with the tendon, creating a featherlike arrangemtn

Question 44

angle of pennation

Answer 44

the angle between the muscle fibers and an imaginary line between the muscle's origin and insertion

Question 45

concentric muscle action

Answer 45

a muscle action in which the muscle shortens because the contractile force is greater than the resistive force

Question 46

eccentric muscle action

Answer 46

a muscle action in thick the muscle lengthens because the contractile force is less that the resistive force

Question 47

isometric action

Answer 47

a muscle action in which the muscle length does not change because the contractile force is equal to the resistive force

Question 48

classic formula

Answer 48

the load lifted is divided by body weight to the two-thirds power

Question 49

inertial force

Answer 49

can act in any direction

Question 50

bracketing technique

Answer 50

the athlete performs the sport movement with less than normal and greater than normal resistance

Question 51

friction

Answer 51

the resistive force encountered when one attempts to move an object while it is pressed against another object

Question 52

fluid resistance

Answer 52

the resistive force encountered by an object moving through a fluid

Question 53

surface drag

Answer 53

results from the friction of a fluid passing along the surface of an object

Question 54

form drag

Answer 54

results from the way in which a fluid presses against the front or rear of an object passing through it

Question 55

lordotic

Answer 55

a normal, slightly arched back

Question 56

kyphotic

Answer 56

slightly rounded, as the back is in its normal s shape

Question 57

Valsalva maneuver

Answer 57

when the glottis is closed, thus keeping air from escaping the lungs, and the muscles of the abdomen and rib cage contract, creating rigid compartments of liquid in the lower torso and air in the upper torso