Gait Cycle

March 6, 2021 | By : OrthoFixar | Foot Surgery
| Last updated on March 30, 2021


Learning and understanding gait cycle is very important in evaluating lower limb problems, as much can be learnt by carefully studying the way the patient walks and moves.

  • A single gait cycle consists of a stance phase (60%) and a swing phase (40%).

Definitions

  • Stride: it’s one full gait cycle from heel strike to another heel strike.
    • It’s measured from initial contact at the start of stance to the next initial contact of the same foot.
    • Each stride is composed of a stance phase and a swing phase.
  • Stance Phase: it’s the period of time when the foot is on the ground, in which the leg accepts body weight and provides single limb support.
    • 60% of one gait cycle.
  • Swing phase: it’s the period of time that the foot is off the ground, in which the limb advances forward.
    • 40% of one gait cycle
  • Step: it is the distance between initial contacts of the alternating feet.
  • Walking: it’s a period of double limb support in addition to always having one foot in contact with the ground throughout the gait cycle.
  • Ground reaction forces (GRF): it is the force exerted by the ground on a body in contact with it.
    • GFR is approximately 1.5 times body weight during walking and 3 to 4 times body weight during running.
See Also: Ankle and Foot Anatomy

Stance Phase

Stance phase forms 60 % of gait cycle. It starts from the heel strike to toe off phase of the same foot.

Heel Strike

  • Defined as the initial contact of the foot heel on the ground.
  • Muscles actions:
    • Hip extensors contract to stabilize the hip.
    • Quadriceps and tibialis anterior muscles contract eccentrically.
      • Controls the rate at which foot strikes the ground.
  • Hindfoot is locked/inverted at initial strike allows for energy absorption

Foot flat

  • Gastrocnemius-soleus complex eccentrically contracted during flat foot position.
    • Controlling forward progression of body over the foot.
  • Hindfoot is unlocked/everted for ground accommodation.

Mid-stance

  • From elevation of opposite limb until both ankles are aligned in coronal plane.
  • Hip extensors and Quadriceps muscles has a concentric contraction.

Terminal stance

  • Begins when the supporting heel is of the ground, and continues until the opposite heel touches the ground.
  • Toe flexors and tibialis posterior muscles contract (the most active muscles during this phase).

Swing Phase

Toe-off

  • Defined as the time from elevation of limb (toes are off the ground) to maximal knee flexion.
  • Gastrocnemius-soleus complex has a concentric contraction.
  • Hindfoot supinates, with activating the posterior tibialis tendon.
  • Transverse tarsal joint locks and provides a rigid lever arm for toe-off

Mid-swing

  • Defined as the time from maximal knee flexion to where the tibia is vertical to the ground.
  • Ankle dorsiflexor muscles contract to ensure foot clearance.

Terminal swing

  • Defined as the time from where the tibia is vertical to just prior to another initial contact (heel strike).
  • Hamstring muscles decelerate forward motion of the thigh.

Center of gravity (COG)

  • In standing position: it’s located 5 cm anterior to S2 vertebral body.
  • During gait cycle COG displaces vertically.
    • While it displaces 5 cm horizontally during normal gait cycle.

Abnormal Gait patterns

Antalgic gait

  • A markedly shortened stance phase on one side.
  • Pain makes the patient move off the affected limb as quickly as possible.
  • The step length may be short

Scissoring gait

  • A stiff-legged gait with the legs crossing each other is often associated with the muscle imbalance found in cerebral palsy.
  • Often, there is also a crouched posture with flexed hips and knees, feet that are in equinus and both limbs internally rotated.

Drop-foot gait

  • During swing phase, there is no ‘pick up’ of the foot so it effectively ‘drops’ into equinus; if the foot was not lifted higher than usual to accommodate this, the toes would drag along the floor.
  • This is caused by disorder or damage to the peripheral nerves supplying the foot dorsiflexors (peroneal nerve)

High-stepping gait

  • This could be due to a bilateral foot drop or it may signify problems with balance or proprioception.

Waddling (Trendelenburg) gait

  • The trunk is thrown from side to side with each step.
  • The mechanics are similar to those that produce a positive Trendelenburg test as seen in patients with functionally weak abductor muscles of the hip, perhaps due to dislocation or simply pain.

See Also: Trendelenburg Test

Ataxic gait

  • Ataxia produces a more obvious and irregular loss of balance, which is compensated for by a road-based gait, or sometimes uncontrollable
    staggering.

Dystonia

  • Dystonia refers to abnormal posturing (focal or generalized) that may affect any part of the body and is often aggravated when the patient is concentrating on a particular motor task such as walking.


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