Gait Cycle Phases: Stance and Swing

• When observing gait pattern, you only look at one limb at a time.
• Gait cycle starts when the heel of the observed extremity hits the ground.
• Gait cycle ends when the heel of the same extremity hits the ground again

Gait Cycle Phases

• Divided into stance and swing phases.

Stance Phase

• Foot of the referenced lower extremity makes contact with the ground.
• Constitutes 60% of the gait cycle
• A single gait cycle contains right and left stance phases

Swing Phase

• Foot of the referenced lower extremity is not in contact with the ground.
• Constitutes 40% of gait cycle
• A single gait cycle contains right and left swing phases

Double Support Time

• Body weight is transferred from one foot to the other while both feet are on the ground.
• One period of double support occurs early in the stance phase.
• The other period occurs late in the stance phase of the referenced extremity.
• About 20% of the gait cycle is spent in double limb support, with the other 80% in single limb support

Gait Values

• Stride is the distance between successive points of heel contact of the same foot.
• A stride involves 2 steps: left and right, and = to a gait cycle.
• The average stride distance is ~1.4 meters.
• Step is the distance between heel contact points of one foot and the other foot.
• Left step length: measured from the right heel to the left heel
• The average step length is ~0.7 meters.
• Velocity is the total distance traveled in a given amount of time.
• Average walking speed is ~1.3 meters per second.

Rancho Los Amigos Terminology

• Traditional gait terminology should be known.
• The Rancho Los Amigos terminology is included in the stance and swing phase.

Traditional vs. Rancho Los Amigos Terminology

• Traditional stance: heel strike, foot flat, midstance, heel off, toe off
• Rancho Los Amigos stance: initial contact, loading response, midstance, terminal stance, pre-swing
• Traditional swing: acceleration, mid-swing, deceleration
• Rancho Los Amigos swing: initial swing, mid-swing, terminal swing

Gait Analysis: Stance Subphases

• Initial contact (heel strike): is double limb support and marks the beginning of stance phase.
• It occurs when the heel strikes the ground.
• Breaking response in gait
• Most muscles work eccentrically.
• Hip extensors contract eccentrically to slow down and stabilize the limb
• Quads contract concentrically initially to hold knee in extension and then eccentrically to control knee flexion
• Tibialis anterior contracts eccentrically to prevent foot slap
• Joint ROM requirements include hip at 30° flexion, knee at 0°-15° flexion, and ankle at 0°-15° plantar flexion.
• Loading response (foot flat): occurs after initial contact until elevation of opposite limb and the body weight is transferred on to the supporting limb
• Tibialis anterior continues to contract eccentrically to control plantar flexion moment at ankle
• Quads initially contract eccentrically to stabilize the knee and counteract knee flexion then concentrically extending the knee
• Joint ROM requirements are 30° flexion to 5° flexion at the hip
• Midstance: body weight is transferred and the single limb support.
• Begins when the opposite limb leaves the ground
• Body aligns directly over the stance leg.
• Hip extensors and quadriceps contract concentrically to advance the body forward over the stance leg
• Gluteus medius contracts eccentrically to control pelvic alignment
• Gastrocnemius and soleus eccentrically contract to control advancement of tibia over foot
• Knee: 15° -5° flexion
• Ankle: 15° PF -10 DF
• Terminal stance (heel off): marks the last single limb support.
• It begins when the supporting heel rises from the ground.
• It goes until the opposite heel the touches the ground
• Gastrocnemius, soleus, peroneals, and flexor hallucis longus contract concentrically to plantar flex the ankle
• This leads to Hip: 10° hypertext - 0° (neutral)
• Start to see the initiation of windlass mechanism
• Pre-swing (toe off): marks the start of the second double limb stance in gait cycle.
• It begins from initial contact of opposite limb and goes to just prior to elevation of reference limb
• Hip flexors contract to propel the advancing limb forwards
• Knee flexion is relatively passive
• Plantarflexors generate push-off.
• Ankle plantar flexors continue to contract concentrically for push off
• Resulting in Hip: 0° (neutral) - 20° flexion
• Knee: 5°-40° flexion
• Great toe: 65° - 70° extension at toe off

Gait Analysis: Swing

• Initial swing (acceleration): Elevation from limb to the point of max knee flexion
• Hip flexors and rectus femoris contract concentrically to advance the swinging leg
• Hamstrings contract concentrically to flex the knee
• Ankle dorsiflexors contract concentrically to ensure foot clearance
• This results in Hip: 20° - 30° flexion
• Knee: 40° - 60° flexion
• Mid-swing: maximal knee flexion to tibia vertical
• Quadriceps begin to concentrically contract to extend the knee
• Ankle dorsiflexors continue to concentrically contract
• This results in Hip: 30° flexion
• Knee: 60°- 30° flexion
• Terminal swing (deceleration): from tibia vertical to just prior to initial contact
• Eccentric activation of hamstring muscles decelerates forward motion of thigh
• This results in Hip: 30° flexion
• Knee: 30° flexion - o° (neutral)

Normal ROM required for gait

• Hip: 10° extension - 30° flexion
• Knee: 0° - 60° flexion
• Ankle: 15° DF - 20° PF
• Great toe: 0° - 65°/70° extension

Four main challenges of gait

• Maintaining upright posture
• Maintaining equilibrium
• Controlling foot trajectory and ground clearance
• Control multiple body segments
• 3 main tasks are Weight acceptance, Maintenance of stability during single leg support, Limb advancement (swing)

Analysis Of Shoes and Orthotics

• Shoes should have Increased wear over the lateral heel.
• Even wear along the area corresponding to the 1st, 2nd, and 3rd MTP joints.
• Even wear over the 1st, 2nd, and 3rd MT heads.
• It is best to use exercise before orthotics to correct the biomechanical faults.
• Refer to an orthotist for custom orthotics, if exercise treatment does not work

Gait Patterns

• Antalgic gait: is a pattern seen when a patient has pain in one of their lower extremities.
• Weight bearing is reduced on the affected limb
• There will be decreased step length of the unaffected limb which will result in decreased stance time on the affected limb
• Side flexion towards affected limb during stance if hip = pain source
• Cane held contralateral to affected limb
• Foot drop: Ankle DF weakness will result in abnormal compensatory gait.

Steppage Gait

• Patient cannot DF and excessive hip and knee flexion is used to clear the foot.
• Foot slap: Patient has weak or absent dorsiflexors and the foot slaps down
• Hip hiking is used on the affected limb during swing

Other Gait Abnormalities

• Abducted lurch: Leaning over the affected hip leads to compensatory technique for gluteus medius weakness
• Gluteus maximus gait: Trunk thrown backwards after initial contact may be due to glut max weakness
• Parkinsonian gait: forward flexed trunk, head and neck, narrow base, small shuffling steps + lack of arm swing
• Ataxic gait: wide base of support, irregular steps and unsteady gait pattern
• Scissoring gait: Most commonly seen in spastic cerebral palsy. Legs cross midline due to spasticity of adductors
• Hemiplegic gait:
• Weak hip abductors will result in Trendelenburg sign.
• Knee hyperextension due to quadriceps spasticity OR knee flexion throughout stance from knee flexion contracture and or weak quads
• Loss of heel strike from ankle DF weakness
• Decreased stance time on affected limb

Trendelenburg Sign

• Trendelenburg sign: opposite pelvis drops during single leg stance + compensated Trendelenburg if body flexes ipsilaterally to compensate due to gluteus medius and minimus weakness
• Gluteus medius and minimus weakness
• Lesion in superior gluteal nerve – common pregnancy