Kinesiology Quiz 2

Shows the path of pressure point under the foot during gait

Center of Pressure (CoP)

Which phase is known as the acceleration, action, motion, or contact phase (action part of the movement/skill) and characterized by near maximal concentric activity in the involved muscles?

Movement phase

What are two subcategories of agonist muscles

Primary/prime movers (location, length, size, shape, force is greater or assisters/assistant movers (contribute less to joint motion) ** there is not always a consensus on which muscles are primary movers and which are assistants

Another name for follow through phase

deceleration phase

Gait analysis is....

functional evaluation of walking or running

distance between the points of contact of both feet

step width

joints should be analyzed in respect to.....

various stages

In which phase (ex. baseball pitch) would the right shoulder girdle is fully retracted in combination with abduction and maximum external rotation of the glenohumeral joint? (completion) of phase

Preparatory phase

What is the "cocking" or "winding up" stage?

Preparatory phase

What is the most critical phase in leading toward the desired result of the activity?

Preparatory phase

Which phase is used to lengthen appropriate muscles so they are in position to generate more force and momentum when the concentrically contract in the following phase (also becomes more dynamic as the need for explosiveness increases)?

Preparatory phase

Which phase: extending the throwing arm posteriorly and rotating the trunk to the right in conjunction with left hip flexion?

Preparatory phase

Insertion not always the most moveable/origin most stable. Give an example

Pull up; (biceps brachii) radius is stable but scapula moves upwards

How does running gait cycle differ from walking gait

RGC has a flight phase (neither foot in contact with supportive surface and no period of double limb support)

non rotary component angle LESS than 90 degrees

STABLIIZING force (pulling bone toward joint axis

What muscles surround joint/body part; contract to fixate or stabilize the area to enable another limb or body segment to exert force and move; "fixators"; essential in establishing firm base for more distal joints to work from when carrying out movements

Stabilizer muscles

What are some common (but not necessary) phases in sport skills?

Stance (beginning) and recovery (end)

Which phase is supportive v. which is not

Stance is supportive and swing is non supportive

What phase is occurring when a baseball player assumes position with ball in glove waiting to receive signal from catcher?

Stance phase

What phase of movement allows the athlete to assume a comfortable and balanced body position from which they initiate the skill

Stance phase

What muscle assists in the action of agonists, not necessarily prime movers for the action, "guiding" muscles, assist in refined movement and rule out undesired motions; "helping synergists"

Synergist muscles

What kind of muscles are the anterior and posterior and deltoid examples of and why

The anterior deltoid acts as an agonist in glenohumeral flexion, while the posterior deltoid acts as an extensor and by helping each other they work in synergy with the middle deltoid to accomplish abduction

muscles that cross and act directly only on the joint that they cross

Uniarticular muscles

types of muscles:

agonist, antagonist, stabilizer, synergist, neutralizer, force couple

When kicking a ball, hip flexors and knee extensors are the _________

agonists

When kicking a ball, hamstrings that relax to allow the kick to occur are _________

antagonistic

Quadriceps muscles are __________ to hamstrings in knee flexion

antagonists

Elbow extensors are what to elbow to elbow flexors and why

antagonists; they produce opposite actions

"Open chain":

any one "link" in the extremity may be moved individually without significantly affecting other links; distal end of extremity is NOT fixed to relatively stable surface

What changes with speed increase

arms swing, stride length, cadence, knee flexion range of motion, muscular force, speed of contraction, less up and down motion.

muscles that cross and act on two different joints

biarticular muscles (can effect one or both joints depending)

What makes up the "chain" of the kinetic chain concept

bony segments and their linkage system of joints

number of STEPS taken per unit time (ex. steps/min)

cadence

What kind of exercise would it be desirable to begin with angle of pull at 90 degrees

chin up or pull up (angle makes it easier bc of a more advantageous angle of pull)

What is more functional: open or closed chain exercises

closed

Lower extremity activities are more likely to be __________ chain activities, and upper extremity activities are more likely to be___________ chain

closed; open

Rotary/Vertical component

component of muscular force that acts perpendicular to the long axis of the bone/lever

What do high amounts of eccentric activity accomplish?

deceleration of the body and especially the arm

Passive insufficiency example

hamstrings usually cannot stretch enough to allow for full knee extension and maximal hip flexion

Which kind of activity accomplishes deceleration of the body (especially the arm)

high amounts of eccentric activity

When kicking a ball, preciseness depends upon _____

involvement of many other muscles

what happens to a muscles ability to exert force as it shortens

is decreases/diminishes

Biarticular knee and hip muscles (countercurrent movement)

kicking; during lower extremity movement phase, rectus femoris concentrically contracts to flex hip and extend knee; when these two movements are combined, tension increases or stretch hamstring muscles at both knee and hip

Angle of pull can compensate for

lack of insufficient strength

gait velocity

meters per second

At what points is the body supported by a single leg

midstance and terminal stance

What constitutes efficient gait

minimal side to side motion with maximal forward motion

What is a positive result of coupling muscle forces

more efficient movement

which phase begins with forward movement of the arm and continues until ball release?

movement phase

What happens if follow through occurs too soon?

movement phase is inappropriately cut short and has a less than desirable result in the activity

What is a "helping synergist"

muscles that have an action in common but also have actions antagonistic to each other; help another muscle move the joint in the desired manner and simultaneously prevent undesired actions

What do abduction and adduction do to each other and what does the common action of these two muscles ((Pectineus and tensor fascia latae)) usually result in

neutralize; hip flexion

What phases will all sports skills include?

preparatory, movement, and follow through

Examples of closed chain exercises

push up, dip, squat, dead lift (most physical activities)

Active insufficiency example

rectus femoris contracts concentrically to flex hip and knee (can completely preform either action at one time but actively insufficient to obtain the full range at both joints simultaneously; countercurrent movement pattern)

What is the recovery phase used for?

regain balance and positioning to be ready for next movement demand

What kind of motion occurs in the stance phase?

relatively static, short ranges of movement

Step

sequence of events from a specific point in the gait on one extremity to the same point in the opposite extremity

What is the emphasis of the stance phase

setting various joint angles in correct positions in respect to one another and to the sport surface

path of center of gravity is what kind of curve

sinusoidal

Are joint movements and insertions usually involving small or large angles of pull

small

Horizontal/ non rotary components

stabilizing or dislocating components

distance traveled between the initial contacts of the left and right foot

step length

gait cadence

steps per minute

two sequential steps is a

stride

linear distance covered in one stride

stride length

time required to complete a single stride

stride time

"closed chain":

substantial movement of any one link cannot occur without substantial and subsequent movement of other links

(kicking a ball) what muscles assist in refining the kick and preventing extraneous motions (not primarily responsible for knee extension and hip flexion, but contribute to accuracy

synergists

During the movement phase, where is the summation of force directed?

the ball, sport object, or opponent

What are some factors that muscle actions are dependent upon

the motor units activated, joint position at time of contraction, planes of motion allowed in the joint, axis of rotation possible in the joint, muscle length, relative contraction or relaxation of other muscles acting on the joint

When kicking a ball, why do the contralateral hip and pelvic areas need to be under relative tension and what helps them accomplish this?

the relative tension helps stabilize and fixate the pelvis on one side to provide a relatively stable base

when is passive insufficiency reached

when opposing muscles become stretched to the point where it can no longer lengthen to allow movement

when is active insufficiency reached

when the muscles becomes shortened to the point that is cannot generate or maintain active tension (muscle cant shorten any further)

What causes force couples (muscles) to occur

when two or more forces are pulling in different directions on an object, causing the object to rotate about its axis

What are the advantages of biarticular over uniarticular muscles

- cause/control motion at more than on joint -able to maintain relatively constant length due to shortening at one joint and lengthening at another

What are some examples of neutralizer muscles

- supination action of biceps brachii is desired, triceps brachii contracts to neutralize the flexion action of the biceps brachii -bicep curl: when only the flexion force of the biceps brachii is desired, the pronator teres contracts to neutralize the supination component of the biceps

What two distinct/major phases of gait occur

1) Weight bearing stance phase and 2) non weight bearing swing phase

Rotary force (90 degrees)

100% of force is contributed to movement; all being used to rotate lever about its axis; closer pull to 90 degrees, greater the rotary component

How many steps do adults average per minute

107 +/- 2.7 (104.3-109.7)

How do you calculate vertical ground reaction force

2.0-6.0 x the body weight

How many phases do movements usually involve?

3-5 depending on complexity

how many cm does the body approx. rise and fall during gait cycle

5cm

What muscle type causes joint motion through a specified plane of motion when contracting concentrically

Agonist

Angle b/w line of pull of the muscle and the bone on which it inserts (angle toward the joint)

Angle of Pull

What muscle type is located on opposite side of joint from agonist muscle, has an opposite concentric action, "contralateral" muscles, works with agonist muscles by relaxing and allowing movement, when contracted concentrically they preform joint motion opposite to the agonist

Antagonist (contralateral) muscles

Example of a uniarticular muscle

Brachialis; can only pull humerus and ulna closer together

Distal end of an extremity is fixed; movement of one joint cannot occur without casing predictable movement of other joints in the extremity; multiple joints and muscle groups are involved to cause and control movement through multiple planes

Closed chain movement/exercise

non rotary component angle GREATER than 90 degrees

DISLOCATING (pulls bone away from joint axis)

velocity

DISTANCE covered per unit time (ex meters/sec)

Which phase begins at ball release as the arm continues moving in the same direction established by movement phase until velocity decreases to the point that the arm can safely change the movement direction

Follow through

Which phase begins immediately after the climax of the movement phase and brings about negative acceleration of the involve limb or body segment?

Follow through

What is the middle, lower trapezius, and serratus anterior each pulling on the scapula from a different direction to produce combined result of upward rotation an example of

Force Couple Muscles

Pros/cons of open chain exercises

Good for isolating specific joints and concentrating on specific muscle groups but, not functional for most activities because that requires multiple joint effort and muscle groups

What does a greater acceleration in movement phase mean for the follow through phase?

Greater length and importance of FTP

contact of the foot with the ground creates force yielding vertical, anteroposterior (A/P), and mediolateral (M/L) components

Ground Reaction Force (GRF)

Biarticular muscle example

Hip and Knee muscles (if knee extend, rectus femoris shortens and ability to exert similar force to other quadriceps muscles decreases, but its relative length and subsequent force production and capability are maintained due to its relative lengthening at hip joint during extension) (CONCURRENT movement patterns occur when hip and knee extend at same time)

distal attachment or the part that attaches farthest from the midline or center of the body (most moveable part)

Insertion

Describe the role of a stabilizer muscle in a bicep curl

Muscles of scapular and glenohumeral joint must contract in order to maintain the shoulder complex and humerus in a relatively static position so that the biceps brachii can more effectively perform curls - proximal stabilization that enhances the effectiveness of distal joint motion (common in the upper extremity)

how are the muscles of the body used to bring about the initial return to a functional position?

Muscles used eccentrically in the FT phase to decelerate body or limb will be used concentrically in recovery

What type of muscle counteracts the action of another muscle to prevent undesirable movements such as inappropriate muscle substitutions (neutralizing); contract to resist specific actions of other muscles

Neutralizer muscles

Biceps brachii origin and insertion

O: scapula I: radius

In what type of kinetic chain exercise is the core of the body and the proximal segment stabilized while the distal segment is free to move in space through a single plane

Open chain

shoulder shrug, deltoid raise (shoulder abduction, bicep curl, hip flexion, knee extension, and ankle dorsifelxion are all....

Open chain exercises

proximal attachment of a muscle or the part that attaches closest to the midline or center of the body (least moveable part/attachment of muscle)

Origin