|
|
|
Department
of Podiatry
The
Gait Cycle
 |
|
Outline
-
components of gait cycle
- approximate %s of phases
- sagittal plane motion of hip, knee, ankle and subtalar joints
- major lower limb muscle activity
|
The
gait cycle - percentage components - sorry about the quality of this
image, I can't scan it any better - but I'm sure you have similar
diagrams from your first semester biomechanics notes. Michaud's text
has a good diagram as well.
Phases
Stance
phase 62%
- heel contact (HC)
- forefoot contact (FFC)
- midstance (MS)
- propulsion
- heel off (HO)
- toe off (TO)
Swing phase 38%
- early swing
- late swing
- double and single support
The contact period
-
objective: adapt to terrain, shock absorption, forward progression
- 0-10% of gait cycle (HC to FFC)
- at HC: hip flexed, knee extended, ankle in neutral (90°),
STJ supinated
- from HC to FFC: knee flexes, ankle plantarflexes, STJ pronates
Muscle activity:
- long extensors decelerate plantarflexion
- tibialis posterior decelerates pronation
- gastrocnemius decelerates internal tibial rotation
Midstance
-
objective: progression over stationary foot, limb and trunk stability
- 10 - 30% of gait cycle (FFC to HO)
- knee and hip start to extend
- subtalar joint pronation should have ceased (ie. neutral)
Muscle activity:
- tibialis posterior and soleus start to supinate STJ
- peroneus longus stabilizes first ray
- triceps surae decelerate forward displacement of tibia, and plantarflex
ankle joint
Propulsion
-
objective: forward progression, foot becomes 'rigid lever'
- 30 - 60% of gait cycle (HO to TO)
- knee flexes, ankle plantarflexes
- subtalar joint rapidly supinates
- first ray plantarflexes
- 1st MPJ dorsiflexes: toe-off through tip of hallux
Muscle activity:
- soleus and tibialis posterior assist heel lift
- peroneus longus stabilizes first ray
- FHL, FHB, AbH, AdH stabilize hallux
- EHL dorsiflexes hallux
Swing phase
-
objective: forward progression, ground clearance
- 60-100% of gait cycle
- hip continues to flex
- knee extends from flexed position
- ankle dorsiflexes
- STJ slightly pronated at toe-off
Muscle activity:
- long extensors dorsiflex foot for toe clearance
- tibialis anterior dorsiflexes the first ray
Summary
Need to remember
-
components of gait cycle
- approximate %s of phases
- sagittal plane motion of hip, knee, ankle and subtalar joints
- major lower limb muscle activity
 References
Michaud
TC (1993) Foot orthoses and other forms of conservative foot care.
Williams and Wilkins, Baltimore, Chapter 2.
Root ML, Orien WP and Weed JH (1971) Clinical biomechanics: normal
and abnormal function of the foot. Clinical Biomechanics Corp,
Los Angeles, pp.127-148.
Valmassy RL (1996) Clinical biomechanics of the lower extremity.
CV Mosby, St. Louis, Chapter 1.
NB: Walking man graphic taken from the clinical
gait analysis web page of Chris Kirtley
|
|
