Chapter 19 Locomotion: Solid Surface

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Chapter 19Locomotion Solid Surface
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LOCOMOTION

• The act or power of moving from place to place by
  means of ones own mechanisms or power
• In human beings, a result of the action of body
  levers propelling the body
• Ordinarily is by lower extremities
• Occasionally by all four extremities

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WALKINGDescription

• 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
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WALKINGDescription

• Kinematics are often described in terms of
  strides and steps
• One stride is one full lower extremity cycle
• Stride form heel strike to the next heel strike
  of the same leg
• Stride length distance covered in one stride
• Step form heel strike of one leg to heel strike
  of opposite leg

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WALKINGDescription

• Gravity and Momentum chief sources of motion in
  the swing phase (ballistic movement)
• Source of motion for support phase is
• 1st Half momentum of forward moving trunk
• 2nd Half contraction of extensor muscles of
  supporting leg

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WALKINGAnatomical Analysis

• Major Component of Walking
• 1. Pelvic rotation
• 2. Pelvic tilt
• 3. Knee flexion
• 4. Hip flexion
• 5. Knee and ankle interaction

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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

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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

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RUNNINGDescription

• Difference from walking is that there is no
  double support phase
• Running has a flight phase

Fig 19.7
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RUNNINGAnatomical Analysis

• Initial foot contact
• Fast running - ball of foot
• Slow running - heel or whole foot