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The Gait During Ambulation

Locomotion vs. Ambulation
Phase of the Gait Cycle
Parameters that Describe Gait Patterns
Control of Body Center of Mass
Determinants of Gait Cycle During Ambulation

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Objectives¡G After studying this topic, the students will be able to

  1. to describe types of locomotion
  2. to describe a normal gait cycle
  3. to identify spatial and temporal parameters that describe gait pattern and their significance
  4. to understand determinants of a normal gait cycle during level walking

  1. Simoneau GG (2002).  Kinesiology of walking.  In Neumann DA: Kinesiology of the Musculoskeletal System: Foundations for Physical Rehabilitation. Philadelphia: Mosby.  Chapter 15, pp. 523-551.
  2. Smith LK, Weiss EL, Don Lehmkuhl L (1996). Brunnstrom's Clinical Kinesiology, 5th ed.  Philadelphia, F.A. Davis.  Chapter 12, pp. 410-422.
  3. Barr AE & Backus SI (2001).  Biomechanics of Gait   In Nordin M & Frankel VH: Basic Biomechanics of the Musculoskeletal System.  Philadelphia: Lippincott Williams & Wilkins. Chapter 18, pp.438-443.

Locomotion vs. Ambulation

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Definition

  • locomotion
  • the act or power of moving the body from place to place by means of one's own mechanisms or power
  • ambulation
  • one type of locomotion which is characterized by moving the body on the level surface

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    Types of Locomotion

    Types Examples
    on feet
  • walking (ambulation, level walking)
  • race walking
  • running
  • ascending or descending ramp
  • ascending or descending stairs
  • jumping
    • on wheels
  • bicycling
  • roller skating
  • ice skating
  • wheelchair propelling
    • on hands
  • walking on hands
  • crutch walking
  • stunts
    • on hands and knees
  • creeping
  • crawling
    • on hands and feet
  • bear walking
  • ropewalking
    • rotary locomotion
  • cartwheels
  • handsprings
  • rolls

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    Phases of the Gait Cycle

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    Contributors to gait analysis

    Researcher Year Technology Contribution
    Weber brothers¡G
    Wilhelm Weber (physicist)
    Eduard Weber (anatomist)    		 1836 chronometer and telescope with a scale 1st book related to gait¡G "The Mechanics of Human Motions"
    to measure and define some spatial and temporal parameters, such as stance and swing phases
    E. J. Marey
    (French physiologist)    		 1873 pneumatic switch (shoes with air chambers attached to a recorder)
    geometric chronophotography (multiple exposures superimposed on the same photographic plate, 10 Hz)
    the use of black-dressed subject with brilliant metal buttons and shinning bands    		 1st person to record the duration of foot contact with the ground in level walking




    pioneer of the modern motion capture technique
    K. H. Vierordt 1881 ink in small spray nozzles attached to the shoes ¡@
    E. Muybridge 1887 serial photography¡G 48 electrophotoraphic cameras with simutaneous exposures to record trotting horse and demonstrate the air-flight phase
    Wilhelm Braune
    (German Anatomist)
    Otto Fisher
    (German mathematician)    		 1890's - 1907 4-camera system with light-tube attached on the body segment and the rectangular coordinate system superimposed 1st research using 3D analysis of gait
    to establish the calculation methods for mechanical parameters of gait
    Scherb 1927 electric switch¡G 3 separate switches embeded in the shoes ¡@
    Elftman 1938 force platform kinetic research in normal and pathological gait pattern
    Frankel 1950 force platform kinetic research in normal and pathological gait pattern
    M. P. Murray (PT) 1960's
    -1980's    		 interrupted-light photography (1964)¡Flater 3D imaging system kinematic research in normal and pathological gait pattern, especially for artificial limbs
    Sutherland and Hagy 1972 cameras with superimposed Y-Y coordinate system
    synchronized EMG    		 trigonometric method to calculate angle of joint motion using true length and measured length
    Andriachi 1977 pressure transducer kinetic research
    V. T. Inman 1981 3D imaging system
    force platform
    EMG    		 ¡@
    David A. Winter 1979 3D imaging system
    force platform
    EMG    		 "The Biomechanics and Motor Control of Human Gait"
    J. Perry 1992 single axis paralleogram elgons development of a system of gait terminology for both normal and pathological gaits

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    Gait cycle

  • gait¡G the style of walking
  • gait cycle¡G a fundamental unit to describe the gait during ambulation, which occurs from the time when the heel of one foot strikes the ground to the time at which the same foot contacts the ground again
    (heel strike à heel strike of the same foot)
  • 2 phases within a gait cycle
  • stance phase (62%)
  • swing phase (38%)
  • A typical gait cycle lasts for 1-2 sec, depending on speed.

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    Stance (Support) phase

  • stance phase¡G the duration when the foot in contact with the ground (heel strike à toe off)
  • 3 periods within a stance phase
  • initial contact period¡G from heel strike to foot flat
  • midstance period¡G from foot flat to heel off
  • propulsive period¡G from heel off to toe off

    • Gait Cycle

    Swing (Recovery) phase

  • swing phase¡G the duration when the foot in the air (toe off à heel strike)
  • 3 periods within a swing phase
  • acceleration
  • midswing
  • deceleration

    • Gait Cycle

    Different terminology used to describe the gait cycle

  • Some traditional-used terms for description of gait does not appear in the pathological gait so that Perry in 1992 developed a system of gait terminology for both normal and pathological gaits.

    • Phase Traditional Terminology Rancho Los Amigos Medical Center
    stance phase heel strike initial contact
    foot flat loading response
    midstance midstance
    heel off terminal stance
    toe off preswing
    swing phase acceleration initial awing
    midswing midswing
    deceleration terminal swing

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    Stride vs. Step

  • stride¡G from heel strike of one foot to the next heel strike of the same foot
  • synonymous with a gait cycle
  • step¡G from heel strike of one foot to the heel strike of the opposite foot
  • 1 stride = 1 gait cycle = 2 steps

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    Double support phase

  • one of characteristics to distinguish walking from running
  • no double support phases during running
  • double support phase¡G part of the stance phase which is characterized by both feet in contact with the ground simultaneously
  • the propulsive period of one leg overlaps the initial contact period of the other leg
  • 2 double support periods during one gait cycle
  • totally ~ 22% within a gait cycle in a comfortable speed

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    Parameters That Describe Gait Patterns

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    Temporal (Time) parameters

    Parameter SI unit Definition Significance
    stride time  sec the duration for the completion of a full gait cycle slightly > 1 sec
    step time  sec the duration for the completion of a right or left step = the reciprocal of cadence for a symmetric gait
    stance time  sec
     %    		 the duration when the foot is on the ground during one gait cycle 62% of one gait cycle
    single support time  sec
     %    		 the duration when only one foot is on the ground during one gait cycle ¡@
    double support time  sec
     %    		 the duration when both feet are in contact with the ground simultaneously during one gait cycle ~22% of one gait cycle
    â as walking speed á
    á in the elderly
    á in patients with balanced disorders
    swing time  sec
     %    		 the duration when the foot is in the air during one gait cycle 38% of one gait cycle
    â as walking speed á

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    Spatial (Distance) parameters

    Parameter SI unit Definition Significance
    stride length   cm distance between 2 successive heel contacts of the same foot â in the elderly
    á as á walking speed
    step length   cm distance between 2 successive heel contacts of the opposite feet ¡@
    step width   cm lateral distance between both heel centers of 2 consecutive foot contacts 7-9 cm in healthy adults
    foot angle
    (degree of toe-out)    		  degree angle between the line of progression of the body and the longitudinal axis of the foot 7º in healthy adults

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    Speed parameters

    Parameter SI unit Definition Significance
    cadence (step rate)  # number of steps per minute comfortable speed¡G 80-110 steps/min
    slow speed¡G <70 steps/min
    fast speed¡G >120 steps/min
    walking speed  m/s
     mph (m/ hr)    		 distance per unit of time á speed ð â in duration of all the component phases, especially double support phase
    á as cadence á, stride length á, or both
    â as angle of toe out â or limb length á
  • comfortable speed defined by Inman et al. (1981)
  • male¡G 105~125 steps/min
  • female¡G 100~120 steps/min
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  • free walking speed on a smooth, level surface between different genders (data from Perry J, 1992)
    • ¡@ Male Female Total
    cadence (step/min) 111 117 113
    speed (m/min) 86 77 82
    speed (km/hr) 5.2 4.6 4.9
    stride length (m) 1.46 1.28 1.41

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    Other kinematic parameters

  • displacement of center of mass
  • angular kinematics of each joint
  • angular displacement
  • angular velocity
  • angular acceleration
  • linear kinematics of each joint center
  • linear displacement
  • linear velocity
  • linear acceleration

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    Control of the Body COM

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    Walking and balance control

  • walking = a series of losses and recoveries of balance
  • Initially, the body leans forward to the limit of stability.
  • Momentary recovery of balance is achieved by placing one foot to a new position.
  • Forward progression is achieved by alternating relocation of the foot.
  • requirement of walking balance
  • efficiency¡G time consuming
  • effectiveness¡G minimum effort and minimum fatigue
  • safety¡G prevention from falls and associated injuries

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    Displacement of body COM during ambulation

  • COM¡G the point in a body about which all the parts exactly balance each other
  • All the linear forces acting on the body is balanced, i.e. SF = 0
  • All the rotary forces acting on the body is balanced, i.e.   SM = 0
  • sinosoid pattern of movement in the sagittal plane¡G 2 full sine waves
  • minimum height of COM¡G at the midpoint of double support (5% and 55% of gait cycle)
  • maximum height of COM¡G at the midpoint of single-leg support (30% and 80% of gait cycle)
  • total excursion¡G 5 cm at the average walking speed
  • displacement depending on the stride length and speed of walking
  • sinosoid pattern of movement in the transverse plane¡G  a single full sine wave
  • minimum right position of COM¡G at the midpoint of stance phase of the right limb (30% of gait cycle as right foot initiates the gait)
  • maximum left position of COM¡G at the midpoint of stance phase of the left limb (80% of gait cycle as the right foot initiates the gait)
  • total excursion¡G 4 cm at the average walking speed
  • displacement depending on the base of support of walking
    1. Ask a young adult to walk on the Treadmill at the speed of 4.5 km/hr, with his/her eyes looking straight forward.  Observe him/her from the side and focusing on path of motions of the ear lobe.  It will simulate the path of the COM of the body in the sagittal plane.
    2. Ask a young adult to walk on a smooth, level surface at his/her comfortable speed, with his/her eyes looking straight forward.  Observe him/her from the side and focusing on path of motions of the ear lobe.  It will simulate the path of the COM of the body in the sagittal plane.
    3. Ask a young adult to walk on the Treadmill at the speed of 4.5 km/hr, with his/her eyes looking straight forward.  Observe him/her from the front and focusing on path of motions of the tip of nose.  It will simulate the path of the COM of the body in the transverse plane.
    4. Ask a young adult to walk on a smooth, level surface at his/her comfortable speed, with his/her eyes looking straight forward.  Observe him/her from the front and focusing on path of motions of the tip of nose.  It will simulate the path of the COM of the body in the transverse plane.

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    Determinants of Gait Cycle During Ambulation

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    Lateral pelvic tilt in the frontal plane

  • lateral tilt to the swing leg during the stance phase
  • to lower down the COM of the body in order to decrease energy expenditure
  • to stretch the hip abductors of the stance leg in order to facilitate their contraction and to increase their strength
  • total excursion¡G 8º at stance phase
  • controlled by hip abductors of the stance leg
  • what would happen if the hip abductors do not work?

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    Knee flexion in the sagittal plane

  • 2 times knee extension during the stance phase
  • knee extension at heel strike
  • 10-15º of knee flexion during the first 15% of gait cycle in order to absorb the impact from ground reaction force (What muscle and what type of contraction would act for this movement?)
  • knee extension again during the midstance period
  • maximum knee flexion of 60-70º occurs at the beginning of midswing (73% of gait cycle)

    • Hip flexion in the sagittal plane

  • 30º of hip flexion during initial contact period to lower the COM
  • hip flexion again during swing phases, reaching maximum hip flexion prior to heel contact
  • what would happen at the pelvis when the hip is flexed at heel strike?

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    Interactions of the knee, ankle, and foot

  • heel strike to foot flat¡G knee flexion, ankle plantarflexion, and foot pronation
  • midstance to toe off¡G knee extension, ankle plantarflexion, and foot supination

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    Pelvic rotation in the transverse plane

  • to minimize the motion of the COM
  • pelvis¡G 10-15º
  • femur¡G 14º
  • tibia¡G 20º
  • foot¡G 6-8º of pronation and 6-8º of supination

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    Physiological Valgus of the Knee

  • to decrease the lateral motion of the COM
  • 1.2º of knee abduction during the whole stance phase
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    Established on 01/03/2003 and Last Updated 01/02/2005 © 2004 Huei-Ming Chai, PhD PT          All Right Reserved