Chapter Four Flashcards
(89 cards)
1
Q
In biomechanics, the term body may refer to which of the following?
I. the human body
II. limb segment
III. piece of chalk
A
All of the above
2
Q
- Which of the following is the equation that represents work?
A. force x distance moved
B. force + distance moved
C. force - distance moved
D. force I distance moved
A
A. force x distance moved
3
Q
Chains can:
*Be used with linear movements.
*The chains add resistance throughout the range of motion.
*Chains can be used in exercises such as the squat or bench press.
A
Chains can:
*Be used with linear movements.
*The chains add resistance throughout the range of motion.
*Chains can be used in exercises such as the squat or bench press.
4
Q
With water resistance, if the surface area is ____, the exercise will be _____
A
*larger; harder
*smaller; easier
5
Q
Kinetics studies the ____ causing or controlling movement, unlike kinematics, which describes motion.
A
forces
6
Q
Force is measured in ____ and causes acceleration according to F = m × a.
A
Newtons
7
Q
Internal forces include ____ contractions, while external forces include gravity.
A
Muscle
8
Q
Newton’s ____ Law states every action has an equal/opposite reaction (e.g., ground reaction force).
A
Third
9
Q
Mechanical work is calculated as force times ____, measured in joules.
A
distance
10
Q
In a bench press lifting 800 N over 0.5 m, the work performed is ____ J.
A
400
11
Q
High-power exercises like ____ cleans require high force and velocity.
A
power
12
Q
Torque is the ____ effect of a force, calculated as force times moment arm.
A
Rotational
13
Q
The moment arm is max when the muscle’s pull on the bone is at ____ degrees.
A
90
14
Q
In a biceps curl, max torque occurs when the forearm is ____ (e.g., 90° elbow flexion).
A
Horizontal
15
Q
Net torque determines movement: zero torque results in ____ action.
A
isometric
16
Q
In a squat, a wider stance increases torque at the ____ and reduces it at the knees.
A
hips
17
Q
The ____ of force development (RFD) is critical for short, explosive tasks.
A
rate
18
Q
Biomechanics applies ____ principles to understand living systems.
Biomechanics uses physics (forces, energy) to analyze movement, focusing on kinematics and kinetics.
A
-Mechanical
19
Q
In biomechanics, a “body” refers to any collection of ____ (e.g., limb segment, chalk).
A
matter
20
Q
____ motion involves rotation about an axis, like a pivot.
A
angular
21
Q
The ____ plane involves flexion/extension movements, like a biceps curl.
A
Sagittal
22
Q
Kinematics studies movement without regard to ____, focusing on variables like velocity.
A
Forces
23
Q
Kinetics examines forces causing movement, with variables like force, work, power, and ____.
A
torque
24
Q
In water exercises, ____-resisted movements oppose buoyant force.
A
Buoyancy
25
Elastic resistance follows ____ Law, increasing with stretch.
Hooke’s Law (F = -k × x)
26
____ resistance, like free weights, remains constant throughout the range of motion.
Constant
27
In weight rooms, “kilogram” is often used to represent ____, not just mass.
Answer: Force
force
28
Force is a mechanical action causing ____ of a body.
**Definition ties to Newton’s Second Law (F = m × a)
Acceleration
29
____ forces, like muscle contractions, originate within the body.
internal
30
31
According to Newton’s Second Law, force equals mass times ____.
Acceleration
F = m × a
32
The ____ Law of Motion explains ground reaction force in running.
third
33
Linear momentum is calculated as mass times ____.
Velocity
m × v
34
Wide stance squats increase involvement of the ____.
adductors
35
The muscle control formula’s first step is to identify the ____ movement.
joint
36
In a biceps curl’s upward phase, the biceps brachii performs a ____ action.
Concentric
37
Slow elbow extension in a biceps curl involves ____ biceps action.
eccentric
38
The stretch-shortening cycle enhances force via ____ energy and neural drive.
elastic
39
Early strength gains are due to ____ adaptations, not hypertrophy.
Neural
40
In the force-velocity relationship, ____ actions produce the most force.
**______ > isometric > concentric
Eccentric
41
The length-tension relationship shows max force at optimal ____ overlap.
Actin-myosin
42
____ muscle fibers, like biceps brachii, are suited for rapid shortening.
Fusiform
43
Muscle contractility generates ____ force for movement.
pulling
44
Muscle efficiency is about ____%, with most energy lost as heat.
25
45
____ movements, like excessive arm swings, reduce exercise economy.
Extraneous
46
Deformational energy is stored in ____ tissues, like the Achilles tendon.
Stretched
**Strain energy is linked to stretch-shortening cycle,
47
Gravitational potential energy is mass times gravity times ____.
height
48
Linear kinetic energy is calculated as ½ mass times velocity ____.
squared
49
____ exercises, like power cleans, optimize power due to high velocity.
explosive
50
A 400 J bench press rep in 1 s produces ____ W of power.
400
51
Power is work divided by ____, measured in watts.
time
52
A ____-class lever has the fulcrum between applied and resistance forces.
first
53
The ____-class lever, like a biceps curl, is most common in the body.
third
Third-class levers require high muscle force
54
Mechanical advantage less than 1 favors the ____ force in third-class levers.
resistance
55
Mechanical work is force times ____, measured in joules.
Distance
W = F × d
56
Lifting 800 N over 0.5 m in a bench press produces ____ J of work.
400
W = F × d
57
Net torque determines movement: zero net torque results in ____ action.
isometric
58
The internal moment arm is max when muscle pull is at ____ degrees.
90
59
Torque is calculated as force times ____ arm (T = F × d).
Moment
60
Angular momentum depends on moment of ____ and angular velocity.
Inertia
61
_____ motion involves rotation about an axis (e.g., elbow joint in a biceps curl).
Angular
62
___ motion is straight (rectilinear) or curved (curvilinear), and general motion combines both (e.g., running).
Linear
63
The barbell in a squat moves ______ (rectilinear path), a form of linear motion. Angular motion occurs at joints (e.g., knee flexion). General motion combines both (e.g., running).
The barbell in a squat moves vertically (rectilinear path), a form of linear motion. Angular motion occurs at joints (e.g., knee flexion). General motion combines both (e.g., running).
64
A lateral raise exercise primarily occurs in which anatomical plane?
frontal
65
____ involves rotation (e.g., trunk twist
transverse
66
Lateral raises involve shoulder abduction/adduction, occurring in the ____ plane.
frontal
67
_____ plane involves flexion/extension (e.g., biceps curl
Sagittal
68
Russian twists involve trunk rotation, occurring in the ____ plane. Squats and biceps curls are ___; lateral lunges are _____.
Russian twists involve trunk rotation, occurring in the transverse plane. Squats and biceps curls are sagittal; lateral lunges are frontal.
69
____ resistance (e.g., barbell bench press) has fixed mass throughout the range of motion. Elastic bands and chains are variable; isokinetic dynamometers are accommodating.
Constant
70
1. What characteristic defines accommodating resistance in a leg press machine?
* A. Resistance increases with stretch, per Hooke’s Law.
* B. Resistance matches the user’s applied force at constant velocity.
* C. Resistance remains fixed, like a dumbbell.
* D. Resistance increases as chains lift off the floor.
Resistance matches the user’s applied force at constant velocity.
71
2. Variable resistance, such as elastic tubing, decreases by what percentage after 501 cycles at 100% deformation?
* A. 1–2%
* B. 5–6%
* C. 10–15%
* D. 20–25%
* B. 5–6%
Elastic tubing loses 5–6% resistance after 501 cycles at 100% deformation, mostly in the first 50 reps. Exam may test specifics of variable resistance fatigue.
72
The internal moment arm (muscle to joint axis) is maximized at ___, producing peak torque (e.g., forearm horizontal in biceps curl).
90*
73
In a squat, maximum external torque occurs when the:
* A. Knees are fully extended at the top.
* B. Barbell is at its lowest point.
* C. Thighs are parallel to the ground.
* D. Hips are fully flexed.
C. Thighs are parallel to the ground.
External torque (load to joint axis) peaks when the moment arm is longest, typically when thighs are horizontal (parallel to ground).
74
10. During the downward phase of a push-up, the triceps brachii performs a ____ action.
* A. Concentric
* B. Eccentric
* C. Isometric
* D. Isokinetic
* : B
* Explanation: The triceps lengthens to control elbow flexion against gravity, an eccentric action. Concentric shortens (upward phase); isometric holds position.
75
Holding a plank position involves which type of muscle action in the rectus abdominis?
* A. Concentric
* B. Eccentric
* C. Isometric
* D. Dynamic
C. Isometric
76
Shoulder press involves shoulder flexion/extension, occurring in the ____ plane (step 4 of formula).
sagittal
77
In a sumo deadlift, the wider stance reduces torque at the ____ compared to a conventional deadlift.
* A. Knees
* B. Hips
* C. Spine
* D. Ankles
* C
* Explanation: Sumo deadlift’s wider stance reduces spinal torque by decreasing hip flexion, increasing adductor involvement.
78
Which exercise best utilizes the stretch-shortening cycle for power development?
* A. Isometric plank
* B. Depth jump
* C. Slow eccentric squat
* D. Biceps curl
* B
* Explanation: Depth jumps involve rapid eccentric (landing) to concentric (jumping) action, maximizing SSC. Planks are isometric; slow squats lack rapid transition; curls are non-plyometric.
79
A wide stance squat increases recruitment of which muscle group compared to a narrow stance?
* A. Quadriceps
* B. Adductors
* C. Gastrocnemius
* D. Erector spinae
* B
* Explanation: Wide stance increases hip abduction angle, recruiting adductors (e.g., adductor magnus) alongside hip extensors. Narrow stance emphasizes quadriceps.
80
Which exercise is an example of a second-class lever?
* A. Biceps curl
* B. Calf raise
* C. Neck extension
* D. Bench press
* B
* Explanation: Second-class levers have resistance between the fulcrum and applied force (e.g., calf raise: ankle fulcrum, body weight resistance, gastrocnemius force). Biceps curl and bench press are third-class; neck extension is first-class.
81
In a second-class lever like a calf raise, the mechanical advantage is typically:
* A. Less than 1
* B. Equal to 1
* C. Greater than 1
* D. Zero
* C
* Explanation: Second-class levers have a mechanical advantage >1 (applied force arm > resistance arm), allowing less muscle force for load (e.g., calf raise).
82
Which inefficiency reduces exercise economy by opposing agonist muscle action?
* A. Jerky movements
* B. Muscular coactivation
* C. Extraneous movements
* D. Excessive center of gravity excursions
* B
* Explanation: Muscular coactivation (antagonist opposing agonist, e.g., hamstrings during knee extension) wastes energy. Other inefficiencies include jerky motions, extraneous movements (e.g., arm swings), and excessive center of gravity shifts.
83
Jerky movements during a deadlift increase energy expenditure due to:
* A. Coactivation of antagonists
* B. Alternating acceleration/deceleration
* C. Isometric contractions
* D. Increased torque
* Answer: B
* Explanation: Jerky movements require metabolic energy to accelerate/decelerate limbs, reducing efficiency.
84
The stretch-shortening cycle in plyometric training enhances force production via:
* A. Increased motor unit recruitment
* B. Elastic energy and neural drive
* C. Higher torque angles
* D. Glycolytic energy supply
* Answer: B
* Explanation: SSC involves eccentric action followed by concentric, storing elastic energy in tissues (e.g., Achilles) and increasing neural drive, enhancing force (e.g., jump squat).
85
In the lowering phase of a deadlift, the hamstrings perform a ____ action to control hip flexion.
* A. Concentric
* B. Eccentric
* C. Isometric
* D. Isokinetic
* B
* Explanation: Hamstrings lengthen to control hip flexion against gravity, an eccentric action.
86
Eccentric control by the quadriceps during a squat descent is critical to:
* A. Maximize power output
* B. Prevent rapid knee collapse
* C. Increase concentric force
* D. Reduce hip torque
* Answer: B
* Explanation: Quadriceps eccentrically control knee flexion to prevent collapse under load, ensuring safety.
87
What is the first step in the muscle control formula for analyzing a biceps curl?
* A. Determine external force effect
* B. Identify joint movement
* C. Name the muscles involved
* D. Identify the plane of movement
* B
* Explanation: Step 1 is identifying joint movement (e.g., elbow flexion in biceps curl). Subsequent steps: external force (gravity), muscle action, plane, muscles shortening/lengthening, name muscles.
88
1. In the muscle control formula, if a muscle acts in the same direction as gravity but slower, the action is:
* A. Concentric
* B. Eccentric
* C. Isometric
* D. Isokinetic
* B
* Explanation: Same direction as external force (gravity) but slower indicates eccentric action (e.g., lowering phase of curl). Concentric is opposite/faster; isometric is no movement.
89
1. In the muscle control formula for a squat’s upward phase, which muscle is named as a primary contributor?
* A. Biceps brachii
* B. Gluteus maximus
* C. Trapezius
* D. Pectoralis major
* Answer: B
* Explanation: Step 6 names muscles (e.g., gluteus maximus for hip extension in squat ascent).
