© 2008 mcgraw-hill higher education. all rights reserved. chapter 19: locomotion: solid surface...

© 2008 McGraw-Hill Higher Education. All Rights Reserved.

Chapter 19:Chapter 19:Locomotion:Locomotion:Solid SurfaceSolid Surface

KINESIOLOGYScientific Basis of Human Motion, 11th edition

Hamilton, Weimar & Luttgens

Presentation Created byTK Koesterer, Ph.D., ATCHumboldt State University

Revised by Hamilton & Weimar

KINESIOLOGYScientific Basis of Human Motion, 11th edition

Hamilton, Weimar & Luttgens

Presentation Created byTK Koesterer, Ph.D., ATCHumboldt State University

Revised by Hamilton & Weimar


ObjectivesObjectives

1. Identify and classify motor skills in categories under the heading of moving the body on the ground or other resistant surface.

2. Describe the anatomical and mechanical nature of the major locomotor patterns.

3. Name and state anatomical and mechanical principles that apply to locomotor patterns.

4. Evaluate the performance of major locomotor patterns.

5. Analyze the performance of a locomotor skill.


LOCOMOTIONLOCOMOTION

The act or power of moving from place to place by means of one’s own mechanisms or power.

In the human being, is the result of the action of body levers propelling the body. Ordinarily by lower extremities. Occasionally by all four extremities. Sometimes by upper extremities alone.


WALKINGWALKINGDescriptionDescription

Alternating action of the two lower extremities.

Translatory motion of the body brought about by rotary motion of some of its parts.

Two phases: Swing & support

Fig 19.1



Kinematics are often described in terms of strides and steps. One stride is one full lower extremity cycle.

Stride: from heel strike to the next heel strike of the same leg.

Stride length: distance covered in one stride. Step: from heel strike of one leg to heel strike

of opposite leg.



Chief sources of motion in the swing phase are gravity & momentum; ballistic movement

Sources of motion for support phase are: 1st Half: momentum of forward moving trunk. 2nd Half: contraction of extensor muscles of

supporting leg.


WALKINGWALKINGAnatomical AnalysisAnatomical Analysis

Major Components of Walking1. Pelvic rotation

2. Pelvic tilt

3. Knee flexion

4. Hip flexion

5. Knee and ankle interaction

6. Lateral pelvic displacement


WALKINGWALKINGAnatomical Analysis:Anatomical Analysis:Swing PhaseSwing Phase

Spine and Pelvis: 1. Movements: Rotation of pelvis toward the

support leg and of spine in the opposite direction; slight lateral tilt of pelvis toward unsupported leg.

2. Muscles: Semipinalis, rotatores, multifidus, and external oblique abdominals on side toward which pelvis rotates.

Erector spinae and internal oblique abdominals on opposite side.

Psoas & quadratus lumborum support pelvis of swinging limb.



Hip: 1. Movements: Flexion; outward rotation;

adduction at beginning and abduction at the end of phase.

2. Muscles: Iliopsoas is prime mover of hip.

Assisted by rectus femoris, sartorius, gracilis, adductor longus.



Knee: 1. Movements: Flexion during 1st half; extension

during 2nd half.2. Muscles: Quadriceps extensors contract

slightly at end of phase. Sartorius & short head of biceps femoris chiefly

following toe off. Largest contributor is knee extensor relaxation at

toe-off.



Ankle and Foot: 1. Movements: Dorsiflexion; prevention of

plantar flexion.2. Muscles: Tibialis anterior, extensor digitorum

longus, extensor hallucis longus, and peroneus tertius contract with slight to moderate intensity at beginning of swing phase, taper off during middle portion of phase. Contract again to prepare for heel strike.


WALKINGWALKINGAnatomical Analysis:Anatomical Analysis:Support PhaseSupport Phase

Spine and Pelvis: Rotation of pelvis toward same side and spine

to opposite side; lateral tilt away from support leg.

Lumbar portion of erector spinae contracts at heel strike to stiffen spine for support.


WALKINGWALKINGAnatomical Analysis: Anatomical Analysis: Support PhaseSupport Phase

Hip: 1. Movements: Extension through foot flat to toe

off. Reduction of outward rotation. Followed by slight inward rotation. Prevention of adduction of the thigh and dropping

of pelvis to opposite side.2. Muscles: During heel strike gluteals and

hamstrings contract statically with moderate intensity, taper off during foot flat and disappear at midstance.

Only muscles active during last part of phase - adductor magnus, longus, and brevis.



Knee: 1. Movements: Slight flexion from heel strike

into foot flat, followed by extension from midstance until heel lift.

2. Muscles: Quadriceps contract moderately in early part of phase, then gradually relax. Vastii contract throughout the 1st half of this

phase. Hamstrings at the end of phase.



Ankle and Foot:

1. Movements: Slight plantar flexion followed by slight dorsiflexion.

Prevention of further dorsiflexion. Plantar flexion of ankle and

hyperextension of metatarsophalangeals at end of propulsive phase.


WALKINGWALKINGAnatomical Analysis: Anatomical Analysis: Support PhaseSupport Phase

Ankle and Foot: 2. Muscles:

Tibialis anterior, extensor digitorum longus and hallucis longus early in phase.

Gastrocnemius and soleus active from midstance to heel off.

Tibialis posterior middle part of phase. Flexor digitorum longus slightly during middle

portion of phase, increase to moderate in the last portion.

Toe and intrinsic muscles respond to pressure of ground against toes.


Action of Upper Extremities Action of Upper Extremities in Walkingin Walking Arms tend to swing in opposition to the legs. This reflex action is usually without obvious

muscular action and serve to balance rotation of the pelvis.

Maximum flexion of shoulder and elbow occurs at heel strike of opposite foot.

Maximum extension of shoulder and elbow occurs at heel strike of same foot.


Neuromuscular Considerations Neuromuscular Considerations Walking relies heavily on reflex. Reflexes also control movements of

supporting limb and trunk in resisting the downward pull of gravity. Stretch reflex: at extremes of motion. Extensor thrust reflex: may facilitate the

extensor muscles of lower extremity as weight rides over the foot on the support leg.


Anatomical Principles Anatomical Principles in Walkingin Walking1. Alignment

a) Reduces friction and decreases the likelihood of strain and injury.

b) Stability of weight bearing limb and balance of trunk over this limb are factors in smoothness of gait.

2. Unnecessary lateral movements decrease gait economy.

a) Excessive trunk rotation with excessive arm motion.

b) Pelvis may drop on one side without support.c) Pelvic rotation should be just enough to enable the

leg to move straight forward.


Anatomical Principles Anatomical Principles in Walkingin Walking

3. Normal flexibility of the joints reduces resistance.

Tendons of two joint muscles of lower extremity contribute to economy of muscular action in walking.

4. Properly functioning reflexes contribute to a well coordinated, efficient gait.

Injury, disease, or substance abuse can interfere with the walking reflexes.


Mechanical AnalysisMechanical Analysis

Translation of the body’s center of gravity forward as a result of the alternating pattern of lower extremity joint movements during the stance and swing phases.

Forces that control walking are; External forces of weight, normal reaction, friction,

air resistance. Internal muscular forces.

Direction & interaction of these forces determine the nature of the gait.


Mechanical Principles in WalkingMechanical Principles in Walking

1. Inertia of the body must be overcome with every step.

2. A brief restraining action of the forward limb serves as a brake on the momentum of the trunk in order to not move the center of gravity beyond the base of support.

3. Translatory movement is achieved by alternating the lower extremity rotary movement between the foot (support phase) and hip (swing phase) (inverted pendulum).



4. The vertical component of ground reaction force serves to counteract the pull of gravity. The horizontal component serves to:

check forward motion during heel strike. produce forward motion during toe off.

5. Speed is increased by increasing stride length, stride rate, or both.

6. Speed is directly related to magnitude of force and direction of application.



7. Efficiency of locomotion partially depends on friction and ground reaction force.

8. Most efficient gait is one that is timed to permit pendular motion of the lower extremities.

9. Alternating loss and recovery of balance.

10. Lateral distance between feet is a factor in lateral stability, with average step width at ~ 10% of leg length.


Walking VariationsWalking VariationsIndividual Variations in GaitIndividual Variations in Gait

Variations may be structural or functional. Structural: body proportions & limb differences. Functional: personality characteristics.

Pathological : disease, injury, or deformity may produce deviations.

Age: decreases in strength and flexibility. Balance becomes a concern.

Obesity: increased impact and propulsive forces. Medial and lateral forces increase.


Walking VariationsWalking VariationsWalking Up & Down Stairs & RampsWalking Up & Down Stairs & Ramps Up stairs or a ramp: Forward lean of body to

direct the push of legs through the body’s center of gravity. Swing phase has exaggerated knee lift and

dorsiflexion of the ankle. Down stairs or a ramp: Eccentric contraction

of muscles to lower body at a controlled rate and maintain line of gravity toward back of the base of support. Swing phase has a slight lifting of rear foot to clear

the step.


Walking VariationsWalking VariationsRace WalkingRace Walking

Adaptations to produce maximum speed.

Must show a period of double support. Minimizes double support period;

Increasing stride rate. Decreasing stride length.


RUNNINGRUNNINGDescriptionDescription

Difference from walking is that there is no double support phase.

Running has a flight phase. Speed is the product of stride duration

and stride length.


RUNNINGRUNNINGDescriptionDescription

Two major types of running Races: concerns are time and

distance. Games and sports: also concerned

with change of direction, pace, and stability.


RUNNINGRUNNINGAnatomical AnalysisAnatomical Analysis

The difference in joint actions between walking and running are a matter of degree and coordination.

Essentially the same action, but the ROM is generally larger in running.


RUNNINGRUNNINGAnatomical Analysis:Anatomical Analysis:Swing PhaseSwing Phase More muscular than pendular and is longer

than support phase. Initial foot contact:

Fast running - ball of foot. Slow running - heel or whole foot.

The flexed leg brings the mass of the leg close to the hip, reducing inertia and increasing angular velocity.


RUNNINGRUNNINGAnatomical Analysis:Anatomical Analysis:Support PhaseSupport Phase The knee and ankle “give” in flexion, then

extend as the body passes over the foot. Support time decreases as speed increases. Movements and muscles in spine and pelvis

are the same as walking, but more vigorous in reaction to leg movements.


RUNNINGRUNNINGMechanical AnalysisMechanical Analysis Speed is governed by length and frequency of

stride. Stride length: determined by length of leg, ROM of

hip, and power of leg extensors. Stride rate: determined by speed of contraction and

skill of performer.

Body becomes a projectile and depends on: Angle of take off. Speed of projection. Height of center of gravity at takeoff & landing.


Mechanical Principles in Mechanical Principles in RunningRunning1. Inertia must be overcome. The problem of

overcoming inertia decreases as speed increases.

2. Acceleration is directly proportional to power in the leg drive.

3. The smaller the vertical component of ground reaction force the greater the horizontal or driving component.

4. The more completely the horizontal force is directed straight backward, the greater its contribution to forward motion of the body.


Mechanical Principles in Mechanical Principles in RunningRunning

5. The length of leg in the driving phase should be as great as possible when speed is a consideration.

6. By flexing the free leg at the knee and carrying the heel high up under the hip, the leg is moved more rapidly as well as more economically.

7. The force of air resistance can be altered by shifting the center of gravity.


The Sprint StartThe Sprint Start

The sprint start enables the runner to exert maximum horizontal force at take off, providing maximum acceleration against inertia.

Fig 19.8


JUMPING, HOPPING, AND LEAPINGJUMPING, HOPPING, AND LEAPING

Goal is to propel the body into the air with sufficient force to overcome gravity and in the direction to accomplish the desired height or horizontal distance.

Path of the body is determined by the conditions at the instant of projection.

Differences between them related to the take off and landing.


Hop, Leap, and JumpHop, Leap, and Jump

Hop: the same foot is used for the take off and landing.

Leap: take off is from one foot and landing is on the other foot.

Jump: take off from one or both feet and land on both feet.

Each may be initiated from a stationary position or preceded by some locomotor pattern.


Total Horizontal DistanceTotal Horizontal Distance

Sum of three distances:1. Horizontal distance between take off foot

and the line of gravity of performer.

2. Horizontal distance the center of gravity travels in the air.

3. Horizontal distance the center of gravity is behind the body part that lands closest to the take off point.


Total HeightTotal Height

May be considered to be divided into: Distance between the ground and the line

of gravity at the moment of take off. Maximum distance the center of gravity is

projected vertically.


Mechanical Principles in Mechanical Principles in Jumping, Hopping, and LeapingJumping, Hopping, and Leaping

1. For movement to occur, inertia must be overcome.

2. Work done by muscles shortening immediately after stretching is greater than that done by those shortening from a static state.

3. Jumpers project themselves into the air by exerting force against the ground that is larger than the force supporting their weight.



4. The upward thrust of the arms in the jump accelerates the support leg downward, which causes a reaction thrust from the ground.

Arm swing action also raises the center of gravity immediately prior to take off, which may result in increased jump height or distance.

5. The magnitude of the impulse that the jumper exerts against the ground is a product of the forces and the time over which they act.



6. The path of motion of a body’s center of gravity in space is determined by the angle at which it is projected, speed of projection, height of the center of gravity at take off, and air resistance.

7. Angular momentum may be developed by the sudden checking of linear motion or by an eccentric thrust.


ADDITIONAL FORMS OF ADDITIONAL FORMS OF LOCOMOTIONLOCOMOTION

Wheels, Blades and Runners Designed to allow humans to move farther

faster for less effort, or to move quickly and easily over difficult surfaces.

Most common and efficient form is the bicycle.

Fig 19.10


BicycleBicycle

Cycling motion has no braking or retarding phase.

Little kinetic energy is wasted. Speed is determined by slope, gear ratio and

pedal cadence. Force that produces pedal revolution is

provided by a cyclic extension-flexion motion of the lower extremities.

Magnitude of force depends on gear ratio.


Roller (In-line) SkatesRoller (In-line) Skates

Movement is cyclic but not continuous. Force is produced by each leg in turn, with a

period of glide occurring between strokes. During the glide there is a loss of velocity

from friction. Skateboards are similar but use only one leg. Highly efficient during downhill motion.


Ice SkatingIce Skating Very little friction between blades and

ice. Friction further reduced by slight

melting of the ice from pressure of the blade.

Blade sinks into ice and can be used to push off perpendicular to direction of travel.


Ice (Speed) SkatingIce (Speed) Skating

Speed is based on stride length and stride rate.

Trunk is inclined forward to reduce drag from air resistance.

Fig 19.12


Skiing: Cross-Country Skiing: Cross-Country Closely related to walking, running, and

ice skating. Diagonal stride vs. skate stride.

Fig 19.13


Skiing: Alpine of Downhill Skiing: Alpine of Downhill Relies primarily on

gravity for a propulsive force.

At high speeds air resistance plays a role; drag must be reduced through compact body position. Fig 19.14


Rotary LocomotionRotary Locomotion

Factors responsible for rotary locomotion are magnitude, direction, and accurate timing of the forces contributing to the desired movement of the body, including advantageous use of the force of gravity whenever possible.


Rotary LocomotionRotary Locomotion

Achieved by rotating about the body’s successive areas of contact with the supporting surface

Fig 19.15


Locomotion by Specialize Steps Locomotion by Specialize Steps and Jumpsand Jumps

Acrobatic stunts and athletic events: walking on hands, successive jumping,

hurdling. Activities of children’s play and forms of

dance: skipping, hopping, galloping, sliding,

sidestepping, leaping, and standard dance steps.


Chapter 19:Chapter 19:Locomotion:Solid SurfaceLocomotion:Solid Surface

© 2008 mcgraw-hill higher education. all rights reserved. chapter 19: locomotion: solid surface...

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