Gait Analysis – Objectives • To learn and understand: – The general descriptive and temporal elements of the normal walking movement – The important features and components of both the swing and stance phases of the gait cycle – The joint range of motion and muscle activity during walking – The differences between movement patterns, muscle activity, range of motion, and forces of walking and running – The clinical methods of studying gait – Gait changes with normal ageing 1

Gait Analysis – Overview • Source: – Jones, K. & Barker, K. (1996) Human Movement Explained, pp 297-324 (on reserve) • Clinical uses of gait analysis • The gait cycle • Range of motion at the joints in walking • Running analysis – Muscle activity • Clinical methods of gait analysis • Gait changes with age and disease 2

Clinical uses of gait analysis • Assesses the degree and extent of departure from the norm • Documents changes due to therapeutic interventions • Evaluates results of rehab (improvement) 3

Walking Analysis (Human Gait) • Human gait provides a method of locomotion. As a species, we are “bipedal” meaning we move on two extremities.

• Walking, while usually taken for granted by most of us, is an extremely complex movement.

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The gait cycle • Distance and temporal factors in gait (Fig 15.1) – Foot angle, step length, stride length, step width • The gait cycle (Fig 15.2) – Stance phase (60 %) – double support phase (20%) – swing phase (40%) 5

Walking Analysis … the process • A

gait cycle

consists of “the activities that occur from the point of initial contact of one lower extremity to the point at which the same extremity contacts the ground again” • During one gait cycle, each extremity passes through two phases, a single

stance

phase and a single

swing

phase.

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The Gait Cycle: 7

Walking – The Stance Phase 8

Components of the Stance Phase • Stance phase comprises 60% of the gait cycle • Heel strike – moment when the heel first strikes the ground • Foot flat – from heel strike to when the full foot is in contact with the ground • Midstance – body weight is directly over the stance leg • Heel off – moment the heel of the stance leg leaves the ground • Toe off – when only the toe of the stance leg is in contact with the ground 9

Walking – The Swing Phase 10

Components of the Swing Phase • Swing phase comprises 40% of the gait cycle • Acceleration – the toe of the stance leg leaves the ground and begins to swing forward • Midswing – the swinging leg is directly beneath the body • Deceleration – the swinging leg continues forward towards knee extension but is slowing down as it travels, stopping just prior to full knee extension and heel contact with the ground 11

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Range of motion at the joints • Trunk - As left leg moves forward, pelvis rotates clockwise as viewed from above 7 deg • Hip Joint (30 deg flex at HS strike, 180 deg at TO) – Stance - extension, adduction, internal rotation – Swing - flexion/extension, abduction, ext rotation • Knee joint - 180 deg at HS, 160 deg at mid-stance • Ankle joint - Neutral at HS, hinges down during support, and plantar flexes at TO . ROM 30 deg • COM displacement +5 cm bilaterally and vertically (Fig 15.3) 13

Running Analysis…...

• Running is similar to walking BUT, it differs significantly in a number of ways, for example: • No period of “double support” • Float periods (both feet airborne) • Requires greater balance • Requires greater strength • Requires greater ROM at hip, knee, and ankle joints • Involves greater excursion of center of mass • Involves greater ground reaction forces 14

Running – A Gait Cycle 15

Muscle Activity in Running...

• Glut. Max. & med. -- active at the beginning of the stance phase (concentrically) and again at the end of the swing phase (eccentrically).

• Iliopsoas -- active during a portion of the swing phase (concentrically).

• Quadriceps -- 1st 10% of the stance phase (eccentrically) and last 20% of the swing phase (concentrically).

• Hamstrings -- initial portion of the swing phase (concentric) and at the end of the swing phase (eccentric).

• Plantar flexors (gastrocnemius & soleus) – Mid and latter part of stance phase 16

Clinical Methods of Studying Gait • Observational techniques (use checklist, and videotape when possible)(Slide 17) • Quantitative analysis – time-distance measurements (stop watch, footswitches) (Slide 18) – Kinetic techniques (Slide 19 & 20) – Kinematic analysis – Videotaping, semi-automated imaging (Slide 21) – Combined kinematic and kinetic (Slides 20 & 21) 17

Sample gait checklist 18

Analysis aids: Timing of foot contact 19

Analysis aids: Pressure on bottom of feet 20

Force Plates – Measurement of ground reaction forces 21

Optoelectric system - Vicon 22

Gait changes with normal ageing • Lower walking speeds • Shorter step and stride lengths • Reduced plantar flexor force production • Reduced hip extension • Increased double support time • Greater variation in stride width • Wider base of support 23