GAIT (DSA) Flashcards
What are the basic ideas behind gait?
- Forward motion-walking
- Has been compared to a controlled forward fall
- Despite a wide variety of styles gait is remarkably consistent across humans
What is the average step length vs stride length?
Step length = 14-16 inches
Stride length = 28-32 inches
*Stride is the same foot to same foot
Average cadence; which sex is higher?
90-120 steps per minute
Women higher by 6-9 steps
What classifies one gait cycle?
From heel strike to next heel strike of SAME foot
i.e. from left hell strike to left heel strike = 1 gait cycle
What’s involved during contact in a gait cycle?
- Lateral calcaneus strikes ground
- Tibia internally rotates
- Calcaneus everts and talus drops and adducts
- Unlocks midtarsal joint
What provides maximum shock absorption during contact in a gait cycle?
- Calcaneus everting and talus dropping/adducting to unlock midtarsal joints
Which muscles lower foot eccentrically to ground during a gait cycle?
- Extensor digitorum longus
- Tibialis anterior
What portion of the gait cycle is considered mid-stance?
Foot-flat to heel-off
Describe in detail the mid-stance phase of the gait cycle
Rearfoot fully pronates, metatarsals hit ground to bring foot flat on gound, and body’s center of gravity passes from behind to over foot
What happens to subtalar joint during mid-stance phase of the gait cycle?
-Sub-talar joint resupinates (calcaneus everts and talus abducts), locking midtarsal joint, transforming foot from a shock absorber to a rigid lever
What muscle is an important restraint to overpronation and is an active foot supinator during the mid-stance phase of a gait cycle?
Tibialis posterior
What portion of the gait cycle is classified as the propulsion phase?
Heel-lift progresses to toe-off
Extension of which joint results in windlass effect of plantar fascia that elevates the arch and further assists in supination of the foot during the proulsion phase of the gait cycle?
Metatarsophalangeal (MTP) joint, especially 1st MTP (think powerful toe-off)
Proulsion phase of the gait cycle concludes with?
Body weight moving over great toe at toe-off
What occurs during the swing phase of the gait cycle?
Foot dorsiflexes to keep toes from hitting ground and supinates to position foot for lateral calcaneus to make contact at heel strike, and cycle repeats itself
What phase compromises 60% of the gait cycle?
Stance phase -> From heel strike (initial contact) to toe off (pre-swing)
During what phase of the gait cycle do most problems occur?
- During stance phase -> Foot on ground and weight bearing
What phase compromises 40% of the gait cycle?
- Swing phase -> From toe off to heel strike
What is the function of the initial contact phase of a gait cycle?
Establish contact with leading foot, begin STANCE
What is the function of the loading response phase of the gait cycle?
- Shock absorption
- Begin weight bearing
- Continue progression towards forward movement
What is the function of the mid stance phase of the gait cycle?
- Limb and Trunk stability
- Progression over stationary foot
What is the function of the terminal stance phase of the gait cycle?
- Progression past stationary foot
- Prepare for swing
What is the function of the pre-swing phase of the gait cycle?
- Weight release from stationary foot
- Position limb for swing
What is the function of the Initial swing phase of the gait cycle?
- Prepare for foot clearance
- Advance foot from trailing position
What is the function of the mid swing phase of the gait cycle?
- Foot clearance
- Limb advancement
What is the function of the terminal swing phase of the gait cycle?
- Prepare for stance
- Complete limb advancement
Requirements of gait? (5 of them)
1) Stability in stance
2) Foot clearance in swing
3) Pre-position for initial contact
4) Adequate step length
5) Energy conservation
Explain the stability in stance requirement of gait
- Single limb support (40% each foot) for a total of 80% of gait cycle
- Stable foot, ankle, knee, hip, torso
Explain the foot clearance in swing requirement of gait?
Requires coordination of entire limb…
- Ankle dorsiflexion
- Knee flexion
- Hip flexion
- Retain stability in stance
Explain the gait requirements for pre-postion for initial contact?
- Foot-ankle-knee-hip all in correct alignment
- Ready to place foot in desired location
- Ready to absorb weight transfer
If step length in gait is too short what occurs?
- Expend energy
- Minimal progress
If step length in gait is too long what occurs?
- Lose balance
- Strain ligaments and muscles
How is energy conserved during gait?
- Pelvic lift
- In early stance, as weight is transferred, hip on non-weight bearing side DROPS about 2”
How does pelvic rotation help to conserve energy during gait?
- Lengthens femur
- Rotation is about 4 degrees
How does lateral displacement of femur help conserve energy during gait?
- Only 1 foot on ground 80% of time (total both feet in cycle)
- Pelvis shifts laterally about 2”, facilitating adduction of hip during stance
What’s Antalgic gait?
- Painful joint
- Swing enhanced on affected side
- Stance phase shortened on affected side
What’s Arthrogenic gait?
- Stiff joint —> Circumduction-
Plantarflexion of foot opposite to affected side during stance phase to increase clearance (this raises the hip) - Affected leg is circumducted (passive circular motion)
What’s Ataxic gait?
- Unsteady/uncoordinated
- Needs broad base of support
- Loss of sensation or control
Causes of ataxic gait?
- Vestibular
- Cerebellar abscess
- Friedreich’s ataxia
- Pontine-cerebellar atrophy
- Chronic mercury poisoning
- Posterior fossa tumor
- Wernicke’s syndrome
- Drugs
What’s Hemiplegic (circumduction) gait?
- Cerebrovascular event –> Semicircle
- Leg is stiff WITHOUT FLEXION at the knee or hip
- Leg rotated away from body then towards it creating a semicircle
- Seen in strokes and spinal cord injuries
What’s Parkinsonian (Festinating) gait?
- Shuffling! (small shuffling steps)
- Hypokinesia (general slowness of movement)
- Exhibited by SOME pt’s with Parkinson’s disease
Explain a steppage gait
- Foot drop + High stepping + Neuropathic
- Full foot drop
- Hip raised very high to clear toe
- Clomping sounds with high steps
What causes steppage gait?
Peroneal nerve injury secondary to…
- Lumbar disc herniation
- Poliomyelitis
- MS
- Guillain-Barre syndrome
- Parkinson’s disease
