The Gait Cycle: Phases, Parameters to Evaluate & Technology

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Human gait depends on a complex interplay of major parts of the nervous, musculoskeletal and cardiorespiratory systems.


Gait Cycle

The manner or style of walking.

Phases of the Gait Cycle (8 phase model):

  1. Initial Contact
  2. Loading Response
  3. Midstance
  4. Terminal Stance
  5. Pre swing
  6. Initial Swing
  7. Mid Swing
  8. Late Swing

Heel Strike (or initial contact)

Short period, begins the moment the foot touches the ground and is the first phase of double support.

Involves:

30° flexion of the hip: full extension in the knee: ankle moves from dorsiflexion to a neutral (supinated 5°) position then into plantar flexion.
After this, knee flexion (5°) begins and increases, just as the plantar flexion of the heel increased.
Plantar flexion is allowed by eccentric contraction of the tibialis anterior
Extension of the knee is caused by a contraction of the quadriceps
Flexion is caused by a contraction of the hamstrings,
Flexion of the hip is caused by the contraction of the rectus femoris

Foot Flat (or loading response phase)

Body absorbs the impact of the foot by rolling in pronation
Hip moves slowly into extension, caused by a contraction of the adductor magnus and gluteus maximus muscles.
Knee flexes to 15° to 20° of flexion.
Ankle plantarflexion increases to 10-15°.

Midstance

Hip moves from 10° of flexion to extension by contraction of the gluteus medius muscle.
Knee reaches maximal flexion and then begins to extend.
Ankle becomes supinated and dorsiflexed (5°), which is caused by some contraction of the triceps surae muscles.
During this phase, the body is supported by one single leg.
At this moment the body begins to move from force absorption at impact to force propulsion forward.

Heel Off

Begins when the heel leaves the floor.
Bodyweight is divided over the metatarsal heads.
10-13° of hip hyperextension, which then goes into flexion.
Knee becomes flexed (0-5°)
Ankle supinates and plantar flexes
Toe Off/pre-swing

Hip becomes less extended.
Knee is flexed 35-40°
Plantar flexion of the ankle increases to 20°.
The toes leave the ground.

Early Swing

Hip extends to 10° and then flexes due to contraction of the iliopsoas muscle[4] 20° with lateral rotation.
Knee flexes to 40-60°
Ankle goes from 20° of plantar flexion to dorsiflexion, to end in a neutral position.

Mid Swing

Hip flexes to 30° (by contraction of the adductors) and the ankle becomes dorsiflexed due to a contraction of the tibialis anterior muscle.
Knee flexes 60° but then extends approximately 30° due to the contraction of the sartorius muscle.(caused by the quadriceps muscles).

Late Swing/declaration

Hip flexion of 25-30°
Locked extension of the knee
Neutral position of the ankle.
Range of Motion during Gait

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Causes of gait disorders include

Neurological, orthopedic, medical and psychiatric conditions and multifactorial etiology becomes more common with advancing age, making classification and management more complex.
Any gait disorder should be thoroughly investigated in order to improve patient mobility and independence, to prevent falls and to detect the underlying causes as early as possible.
Thorough clinical observation of gait, careful history taking focussed on gait and falls and physical, neurological and orthopedic examinations are basic steps in the categorization of gait disorders and serve as a guide for ancillary investigations and therapeutic interventions.

Hip Pathology

Arthritis is a common cause of pathological gait. An arthritic hip has reduced range of movement during swing phase which causes an exaggeration of movement in the opposite limb ‘hip hiking.
Excessive Hip Flexion can significantly alter gait pattern most commonly due to;
• Hip flexion contractures
• IT band contractures,
• Hip flexor spasticity,
• Compensation for excessive knee flexion and ankle DF,
• Hip pain
• Compensation for excess ankle plantar flexion in mid swing.


Knee Pathologies

Weak Quadriceps. The quadriceps role is to eccentrically control the knee during flexion through the stance phase. If these muscles are weak the hip extensors will compensate by bringing the limb back into a more extended position, reducing the amount of flexion at the knee during stance phase. Alternatively heel strike will occur earlier increasing the ankle of plantar flexion at the ankle, preventing the forward movement of the tibia, to help stabilise the knee joint.
Severe Quadriceps Weakness or instability at the knee joint will present in hyperextension during the initial contact to stance phase. The knee joint will ‘snap’ back into hyperextension as the bodyweight moves forwards over the limb
Knee Flexion Contraction will cause a limping type gait pattern. The knee is restricted in extension, meaning heel strike is limited and step length reduced. To compensate the person is likely to ‘toe walk’ during stance phase. Knee flexion contractures of more than 30 degrees will be obvious during normal paced gait. Contractures less then this will be more evident with increased speeds.


Ankle Pathologies

Ankle Dorsiflexion Weakness results in a lack of heel strike and decreased floor clearance. This leads to an increased step height and prolonged swing phase.
Calf Tightening or Contractures due to a period of immobilisation or trauma will cause reduced heel strike due to restricted dorsiflexion. The compensated gait result will be ‘toe walking’ on stance phase, reduced step length, and excessive knee and hip flexion during swing phase to ensure floor clearance.


Footathologies

Hallux Rigidus results in a lack of dorsiflexion of the great toe. The MPJ uses the windlass effect to raise the arch and stiffen the foot during dorsiflexion of the hallux. This stiffness increases the efficiency of the propulsion portion of the gait cycle. To be efficient in creating stiffness, the hallux should be able to dorsiflex at least 65 degrees.


Leg length discrepancy

Leg length discrepancy can be as a result of an asymmetrical pelvic, tibia, or femur length or for other reasons such as scoliosis or contractures. The gait pattern will present as a pelvic dip to the shortened side during the stance phase with possible ‘toe walking’ on that limb. The opposite leg is likely to increase its knee and hip flexion to reduce its length.


Antalgic Gait

Antalgic gait due to knee pain presents with decreased weight bearing on the affected side. The knee remains in flexion and possible toe weight-bearing occurs during stance phase
Antalgic gait due to ankle pain may present with a reduced stride length and decreased weight bearing on the affected limb. If the problem is pain in the forefoot then toe-off will be avoided and heel weight-bearing used. If the pain is more in the heel, toe weight-bearing is more likely. General ankle pain may result in weight-bearing on the lateral border.
Antalgic gait due to hip pain results in a reduced stance phase on that side. The trunk is propelled quickly forwards with the opposite shoulder lifted in an attempt to even the weight distribution over the limb and reduce weight-bearing. Swing phase is also reduced.

PRESENTATION

Gait Cycle - Phases & A... by Dr Rohit Bhaskar

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