Kinesiology Exam #4
Roll off
-from 40% to 50% of gait -When foot is pushing off the ground
Loading response phase
-last from 0% to 12 % of gait -starts at heel strike of ipsilateral leg, ends at toe off of contralateral foot -"catches mass of body" as gravity pulls it down
Mid stance phase
-lasts from 12% to 30% of gait -begins at contralateral foot toe off, ends when center of gravity is directly above the ball of foot on ipsilateral leg
Terminal stance phase
-lasts from 30% to 50% of gait -begins when center of gravity is directly above the ball of foot on ipsilateral leg, ends at heel strike of contralateral foot. - from 40% to 50% is called roll off, which is when foot is pushing off ground
Preswing phase
-lasts from 50% to 60% of gait -begins at heel strike of contralateral foot, ends at toe off of ipsilateral foot
initial swing phase
-lasts from 60% to 75% of gait -begins at toe off of ipsilateral foot, ends at maximum flexion of knee
midswing phase
-lasts from 75% to 85% of gait -begins at maximum flexion of the knee, ends when tibia is perpendicular to the ground
terminal swing
-lasts from 85% to 100% of gait -begins when tibia is perpendicular to the ground, ends at ipsilateral heel strike.
What should one do to apply maximum pushing force? 1) use the largest possible number of segments 2) use the smallest segments 3) move through a large range of motion 4) move the segments in an ordered sequence, one after the other
1, 3
What are the prime movers in giving top spin to the ball in a tennis stroke with strong forearm pronation? 1. Pronation teres 2. Pronator quadratus 3. Biceps brachii 4. Brachialis
1,2
Which of the following muscles will contract to produce the trunk rotation to the left that is necessary for a right hand throw? 1. Right external oblique 2. Left external oblique 3. right internal oblique 4. left internal oblique
1,4
Principles related to direction of the force
1. Direction the object moves is is determined by the direction of force applied to it 2. If an object can only move along a specific path, any component force not in the direction of the path is wasted. 3. when attempting maximum force production, segments involved should be aligned with the direction of the intended force production (pushing horizontally, align your body horizontally)
Principles related to the point at which the force is applied
1. Force applied in line with an objects center of gravity will cause linear motion 2. Any force applied not in line with an objects center of gravity will cause rotary motion. (freely movable object) 3. If free movement of an object is interfered with (friction), rotary motion may result even if the force is applied in line with the objects center of gravity.
Principles of stability as they apply to pushing a pulling activities
1. Lower center of gravity. 2. widen the base of support in the direction of the line of force. 3. lean into the the force (i.e. lean into someone that is going to push you bakwards) 4. Greater the mass, harder it is to move. 5. the entire body in vertical alignment 6. greater friction between ground and body causes increased stability 7. Focus on an external object that is stationary. 8. positive physical and emotional state.
Anatomical principles related to throwing, striking, and kicking
1. Muscles contract more forcefully if they are first stretched (stretch shortening cycle) 2. Unnecessary movement in an action result in awkwardness and fatigue. Should be eliminated 3. Skillful performance in an action can only be developed by practice 4. The most efficient type of movement in throwing/striking is ballistic. 5. Use the correct anatomical lever for the job (long resistance arm for speed, long effort arm for force)
Principles related to magnitude of the force
1. Object will move only if force is sufficient to overcome inertia. 2. Force exerted is limited by the counter force of the feet on the ground. (friction must hold) 3. To produce maximum force, optimum summation must occur through the body. The max number of body parts possible must move through the greatest ranges of motion possible. 4. To produce maximum accuracy, the smallest # of segments should be used through the smallest range of motion 5. For a change in momentum to occur, force must be applied over time (impulse)
Mechanical principles of throwing
1. Object will move only if force is sufficient to overcome objects inertia 2. The pattern and range of joint movements depends on the purpose of the movement 3. Force exerted by the body can only be transferred in proportion to the effectiveness of the counter force of the feet against the ground 4. linear velocity is imparted to external object as a result of angular velocity of body segments 5. Optimum summation of internal forces is needed if maximum force is to be applied to move an object 6. for a change in momentum to occur, force must be applied over time (impulse) 7. Force applied in line with an object center of gravity will result in linear motion 8. If force applied to a freely movable object is not in line with the object center of gravity, it will cause rotary motion.
Mechanical principles related to hitting, striking, and kicking
1. direction the object moves is determined by the force applied to it 2. momentum is always conserved 3. any change in momentum of individual objects is related to the force and duration of collision 4. the greater the velocity of any approaching ball, the greater the velocity of the ball in the opposite direction after it is struck 5. the greater the velocity of the striking implement, the greater the velocity of the struck ball 6. the greater the mass of the ball (up to a certain point), the greater its momentum after being struck 7. the greater the mass of the striking implement, the greater the striking force 8. The higher the elasticity of the striking implement and the ball, the greater the resultant velocity of the ball will be 9. direction of the struck ball affected by 1. direction of striking implement, 2. relation of striking force to balls center of gravity, 3. firmness of grip and wrist at impact, 4. laws governing rebound
Factors affecting gait
1. environment 2. individual constraints 3. task
goals of locomotion
1. progression: moving from one place to another 2. stability: ability to move without falling 3. ability to adapt: change gait based on environment
Principles related to maintaining and regaining equilibrium
1. the larger the base of support in the direction of the motion, the greater the body's equilibrium will be 2. at the moment of impact, the line of gravity should be centered above the base.
Principles related to avoiding injury
1. the more gradual the loss of momentum, the less force exerted on the body. 2. The larger the area receiving the impact, the less force will be exerted per unit area 3. repeated impacts (running) should be soft impacts whenever possible
principles related to accuracy and control
1. the more gradually the velocity of an object is reduced, the less likely the object is to rebound. 2. keep the eye on the ball 3. catching with accuracy and control depends upon position of the catcher relative to the direction of the incoming object.
Which of the following muscles are active at the elbow during the down phase of the pull-up? 1) triceps brachii 2) biceps brachii 3) anconeus 4) brachialis 5) brachioradialis
2, 4, 5
Which muscles are responsible for the primary action of the humerus in the shoulder joint motion during the propulsive phase of the overarm throw? 1. Anterior deltoid 2. Subscapularis 3. Latissimus dorsi 4. Pectoralis major 5. Posterior deltoid 6. Teres major
2,3,4
Sequential joint action results in...
A curvilinear motion/force at the most distal segment involved.
Simultaneous joint action results in...
A force produced in a straight line
During the swing phase of the gait cycle, which of the following muscles would be most active?
Anterior tibialis
Which of the following tasks involves force production in both the pull and push directions?
Cutting wood with a handsaw
Sequential Movement: Summated Velocity
In a sequential motion, the velocities/forces of each individual body segment adds together to create a summated velocity @ the most distal segment
Sequential movement: End point is curved in nature
In sequential movement, the final segment of the body in motion usually follows a curved pattern. This is because it is rotation around a joint.
Overarm joint action pattern general movements
Prep phase: abducted arm rotates laterally Force phase: abducted arm rotates medially, with elbow extension, wrist flexion, spinal rotation, pelvic rotation.
Which muscles produce hip flexion during the first part of the forward swing phase in walking?
Rectus femoris, sartorius, pectineus, iliopsoas
Why is simultaneous joint action valuable in push and pull actions?
Simultaneous joint action allows all of the movement of the body to be directed along a straight line. A straight line motion is the most advantageous when trying to overcome a heavy object or external force
Definition of midswing
The point in the swinging forward of the leg where the knee becomes maximally flexed.
A double limb support phase is the primary characteristic that distinguishes walking from running.
True
During the swing phase of walking, the pelvis rotates toward the stance leg side and the spine rotates away from the stance leg side.
True
Two of the reflexes that play a prominent role in walking are the stretch reflex and the extensor thrust reflex.
True
Kinetic energy-work relationship
When a body or object is recieved, it has work done on it equal to the change in kinetic energy of the moving body
Sequential transfer of momentum in the body
When the body is moving sequentially, the momentum of one segment when reaching the end of its range of motion will be transferred to the next segment in motion, and this will continue until all momentum is transferred to the acting lever (hand, foot, etc.)
Definition of toe off
When the entire food loses contact with the ground. After propulsion
Which of the following factors has the least effect on the development of momentum in a striking implement?
air resistance
Which of the following would be good advice for safely and efficiently landing from a broad jump?
all of the above
ankle ROM
ankle plantar flexes at heel strike dorsiflexes through to heel off plantar flexes from heel off to toe off dorsiflexes through swing phase
momentum-impulse relationship
any change in momentum requires force applied over a period of time and is equal to the product of that force and the time
Which of the following will not act to increase the force available in a pushing or pulling motion?
applying all forces in sequence
Which best describes the striking segment when hitting a ball with as high a velocity as possible?
be as far from the axis as possible
Which of the following best describes the desired action of the segments contributing to the motion in striking activities where maximum velocity of the implement is desired?
distal segments reach higher velocity than proximal segments
When catching a baseball, what type of muscular contraction is primarily responsible for the deceleration of a hard thrown ball?
eccentric
Which of the following would help to maintain balance when landing from a jump or fall?
enlarge the base of support in the direction of the movement
Which would be the most efficient manner in which to lift a heavy box?
face box with elbows bent and arms close to body
Among other things, what does the concept of "giving" to catch a ball involve?
flexing the elbow at contact
What defines a pushing and/or pulling motion?
flexion and extension of one or multiple joints in a simultaneous movement to exert force on an external object.
Define Impact
force of contact, or violent collision, or striking together.
In which direction is the ground reaction force applied during the propulsion phase of the walk?
forward and upward
muscles active at knee and ankle during terminal stance
gastrocnemeus soleus popliteus flexor digitorum longus flexor hallucis longus tibialis posterior peroneus longus peroneus brevis,
muscles active at hip during loading response
gracilis rectus femoris gluteus maximum semitendonosus semimembranosus gluteus medius gluteus minimus biceps femoris
muscles active at hip during terminal swing
gracilis rectus femoris gluteus maximus semitendonosus semimembranosus gluteus medius biceps femoris
What effect does tucking and doing a shoulder roll have during a fall?
gradually decreases the horizontal velocity
Which segment should be the last to move and have the highest velocity in a throw?
hand
muscles active at hip during midswing
iliacus sartorius gracilis biceps femoris
muscles active at hip during initial swing
iliopsoas iliacus sartorius rectus femoris
How might one decrease the force acting on any given part of the body when landing from a fall? (Select the one best answer)
increase the area that contacts the ground
What should you do when landing from a jump to decrease the amount of force necessary to bring the body to rest?
increase the time of force absorption, increase the range through which the body is decelerated
What makes it difficult for a runner to change either speed or direction?
inertia
knee ROM
knee slightly flexes with heel strike extends during midstance flexes with heel off and continues flexing through midswing extends after midswing to straight
What is the movement in the shoulder (glenohumeral) joint in the delivery and beginning of the follow through of an overarm throw?
medial rotation, horizontal adduction
Why is it easier for a runner to move the recovery leg forward more rapidly when it is flexed when extended?
moment of inertia of the leg is less than when the leg is flexed
Where should the line of gravity be located when receiving impact from an object with a large horizontal velocity?
near the front edge of the base of support
pelvic tilt
pelvis tilts downward away from the leg that is on the ground
Which is an example of the continuous application of a simultaneous pattern?
performing a set of 30 squats
In which part of the walking cycle are the largest forces exerted against the ground?
propulsive phase
muscles active at hip during preswing
rectus femoris adductor longus adductor brevis adductor magnus
Muscles active at hip during terminal stance
rectus femoris adductor longus tensor fascia latae gluteus medius gluteus minimus
Throw-like motions are classified as being ________ in nature.
sequential
Why lift a heavy weight by flexing and then extending the knees rather than flexing at the hips and then lifting the trunk?
shorter resistance arm with squatting
What is the function of the quadriceps muscles when the heel contacts the ground in walking?
stabilize the knee against the reaction force from the floor
stride/stride length
stride is one full gait cycle, so from heel off of right foot to heel off of right foot. Stride length affected by length of legs, balance, neuromuscular control, etc.
Which of the following does not illustrate an underarm throwing pattern?
tennis drive
muscles active at hip during midstance
tensor fascia latae gluteus medius gluteus minimus,
Which of the following determines the amount of force required to stop an object in motion?
the momentum of the object and the time of force application
pelvic rotation
the pelvis rotates to whichever leg is back
Force per unit area/ mechanical stress
the pressure that any part of the body must absorb is inversely proportional to the area over which the force is applied
muscles active at knee and ankle during initial swing
tibialis anterior extensor digitorum longus extensor hallucis longus
muscles active at knee and ankle during midswing
tibialis anterior extensor digitorum longus extensor hallucis longus
muscles active at knee and ankle during preswing
tibialis anterior extensor digitorum longus extensor hallucis longus
Which of the following is the prime mover in elbow extension during the up phase of the push-up?
triceps brachii
Which of the following motions should be avoided in working with long handled implements?
twisting
Which of the following is NOT TRUE when attempting to produce a motion for maximum accuracy?
use the highest possible velocity
overarm joint action pattern immature
uses fewer segments moves simultaneously limited range of motion
muscles active at knee and ankle during midstance
vastus intermedius vastus lateralis vastus medialis gastrocnemeus soleus popliteus flexor digitorum longus flexor hallucis longus tibialis posterior peroneus longus peroneus brevis
muscles active at knee and ankle during terminal swing
vastus intermedius vastus lateralis vastus medialis tibialis anterior extensor digitorum longus extensor hallucis longus popliteus
muscles active in knee and ankle during loading resposne
vastus intermedius vastus lateralis vastus medialis tibialis anterior extensor digitorum longus extensor hallucis longus popliteus
hip adduction and abduction
whatever leg is forward is adducting, whatever leg is back is abducting,
Double support phase
when both feet are in contact with the ground. heel strike of one foot to toe off of the other foot. Transfer of body weight from one leg to the other occurs
definition of mid stance
when center of gravity is directly above the ball of foot on ipsilateral leg
definition of foot flat
when the entire foot is in contact with the ground, occurs after heel strike and lasts until heel off
definition of heel off
when the heel comes up of the ground. The ball of foot and toes are still in contact with the ground.
definition of heel strike
when the heel first contacts the ground
How much work must be done on a medicine ball in order to catch it and completely stop its motion?
work equal to the change in kinetic energy of the ball