1. Chapter 19: Locomotion: Solid Surface
KINESIOLOGY
Scientific Basis of Human Motion, 11th edition
Hamilton, Weimar & Luttgens
Presentation Created by
TK Koesterer, Ph.D., ATC
Humboldt State University
Revised by Hamilton & Weimar

2. Objectives
Identify and classify motor skills in categories under the heading of moving the body on the ground or other resistant surface.
Describe the anatomical and mechanical nature of the major locomotor patterns.
Name and state anatomical and mechanical principles that apply to locomotor patterns.
Evaluate the performance of major locomotor patterns.
Analyze the performance of a locomotor skill.

3. LOCOMOTION
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.

4. WALKING Description 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

5. WALKING Description
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.

6. WALKING Description
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.

7. WALKING Anatomical Analysis
Major Components of Walking
Pelvic rotation
Pelvic tilt
Knee flexion
Hip flexion
Knee and ankle interaction
Lateral pelvic displacement

8. WALKING Anatomical Analysis:Swing Phase
Spine and Pelvis:
Movements: Rotation of pelvis toward the support leg and of spine in the opposite direction; slight lateral tilt of pelvis toward unsupported leg.
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.

9. WALKING Anatomical Analysis:Swing Phase
Hip:
Movements: Flexion; outward rotation; adduction at beginning and abduction at the end of phase.
Muscles: Iliopsoas is prime mover of hip.
Assisted by rectus femoris, sartorius, gracilis, adductor longus.

10. WALKING Anatomical Analysis:Swing Phase
Knee:
Movements: Flexion during 1st half; extension during 2nd half.
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.

11. WALKING Anatomical Analysis:Swing Phase
Ankle and Foot:
Movements: Dorsiflexion; prevention of plantar flexion.
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.

12. WALKING Anatomical Analysis:Support 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.

13. WALKING Anatomical Analysis: Support Phase
Hip:
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.
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.

14. WALKING Anatomical Analysis:Support Phase
Knee:
Movements: Slight flexion from heel strike into foot flat, followed by extension from midstance until heel lift.
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.

15. WALKING Anatomical Analysis:Support Phase
Ankle and Foot:
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.

16. WALKING Anatomical Analysis: Support Phase
Ankle and Foot:
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.

17. Action of Upper Extremities in 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.

18. 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.

19. Anatomical Principles in Walking
Alignment
Reduces friction and decreases the likelihood of strain and injury.
Stability of weight bearing limb and balance of trunk over this limb are factors in smoothness of gait.
Unnecessary lateral movements decrease gait economy.
Excessive trunk rotation with excessive arm motion.
Pelvis may drop on one side without support.
Pelvic rotation should be just enough to enable the leg to move straight forward.

20. Anatomical Principles in Walking
Normal flexibility of the joints reduces resistance.
Tendons of two joint muscles of lower extremity contribute to economy of muscular action in walking.
Properly functioning reflexes contribute to a well coordinated, efficient gait.
Injury, disease, or substance abuse can interfere with the walking reflexes.

21. Mechanical 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.

22. Mechanical Principles in Walking
Inertia of the body must be overcome with every step.
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.
Translatory movement is achieved by alternating the lower extremity rotary movement between the foot (support phase) and hip (swing phase) (inverted pendulum).

23. Mechanical Principles in Walking
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.
Speed is increased by increasing stride length, stride rate, or both.
Speed is directly related to magnitude of force and direction of application.

24. Mechanical Principles in Walking
Efficiency of locomotion partially depends on friction and ground reaction force.
Most efficient gait is one that is timed to permit pendular motion of the lower extremities.
Alternating loss and recovery of balance.
Lateral distance between feet is a factor in lateral stability, with average step width at ~ 10% of leg length.

25. Walking Variations Individual 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.

26. Walking Variations Walking 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.

27. Walking Variations Race Walking
Adaptations to produce maximum speed.
Must show a period of double support.
Minimizes double support period;
Increasing stride rate.
Decreasing stride length.

28. RUNNING Description
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.

29. RUNNING Description Two major types of running
Races: concerns are time and distance.
Games and sports: also concerned with change of direction, pace, and stability.

30. RUNNING Anatomical 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.

31. RUNNING Anatomical Analysis:Swing 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.

32. RUNNING Anatomical Analysis:Support 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.

33. RUNNING Mechanical 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.

34. Mechanical Principles in Running
Inertia must be overcome. The problem of overcoming inertia decreases as speed increases.
Acceleration is directly proportional to power in the leg drive.
The smaller the vertical component of ground reaction force the greater the horizontal or driving component.
The more completely the horizontal force is directed straight backward, the greater its contribution to forward motion of the body.

35. Mechanical Principles in Running
The length of leg in the driving phase should be as great as possible when speed is a consideration.
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.
The force of air resistance can be altered by shifting the center of gravity.

36. The Sprint Start
The sprint start enables the runner to exert maximum horizontal force at take off, providing maximum acceleration against inertia.
Fig 19.8

37. JUMPING, 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.

38. Hop, 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.

39. Total Horizontal Distance
Sum of three distances:
Horizontal distance between take off foot and the line of gravity of performer.
Horizontal distance the center of gravity travels in the air.
Horizontal distance the center of gravity is behind the body part that lands closest to the take off point.

40. Total 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.

41. Mechanical Principles in Jumping, Hopping, and Leaping
For movement to occur, inertia must be overcome.
Work done by muscles shortening immediately after stretching is greater than that done by those shortening from a static state.
Jumpers project themselves into the air by exerting force against the ground that is larger than the force supporting their weight.

42. Mechanical Principles in Jumping, Hopping, and Leaping
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.
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.

43. Mechanical Principles in Jumping, Hopping, and Leaping
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.
Angular momentum may be developed by the sudden checking of linear motion or by an eccentric thrust.

44. ADDITIONAL FORMS OF LOCOMOTION
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

45. Bicycle 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.

46. Roller (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.

47. Ice 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.

48. Ice (Speed) Skating Speed is based on stride length and stride rate.
Trunk is inclined forward to reduce drag from air resistance.
Fig 19.12

49. Skiing: Cross-Country
Closely related to walking, running, and ice skating.
Diagonal stride vs. skate stride.
Fig 19.13

50. 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

51. Rotary 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.

52. Rotary Locomotion
Achieved by rotating about the body’s successive areas of contact with the supporting surface
Fig 19.15

53. Locomotion by Specialize Steps and 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.

54. Chapter 19: Locomotion:Solid Surface