Define the gait cycle
The point of initial contact of one lower extremity to the point of initial contact of the same lower extremity
What are the 2 phases of the gait cycle?
Stance and Swing Phase
Stance phase accounts for __% of the gait cycle whereas swing phase accounts for __%.
60
40
What is the difference between the walking and running gait?
When running there is no double support phase
What are the 5 phases of the stance phase?
1) heel strike (initial contact)
2) flat foot (loading response)
3) midstance
4) heel off (terminal stance)
5) toe off (pre-swing)
Define ground reaction force
the force exerted by the ground on a body in contact with it
3 types of ground reaction forces
- vertical force
- anterior-posterior force
- mediolateral force
What does the vertical force equal and why?
1.2 times the body weight, because it must be greater in order to accelerate
What is the anterior-posterior force?
The force that is overcoming the friction force in order to keep momentum going forward
What does mediolateral force allow for?
greater balance (not required for normal gait)
Describe the ground reaction forces of the gait of someone with the loss of abductor function (weak glute med)
Increased vertical force
Decreased AP force
Increased M-L force
Describe the gluteus medius role in gait
It eccentrically contracts to control the pelvis at midstance
Describe the gluteus maximus role in gait
In concentrically contracts to power hip extension
Describe the ilipsoas role in gait
It concentrically contracts to power hip flexion
Describe the hip adductors role in gait
They concentrically contract to control lateral sway in late stance
Describe the quadriceps role in gait
It eccentrically contracts to stabilize the knee at heel strike
Describe the hamstrings role in gait
Eccentrically contract to control knee extension in swing phase
Describe the tibialis anterior’s 2 roles in gait
Concentrically contracts to dorsiflex the ankle during swing phase
Eccentrically contract to releases foot slowly to allow foot flat during heel strike
Describe the gastrocnemius role in gait
Concentrically contracts to pus off during preswing
Describe the soleus role in gait
Eccentrically contracts to inhibit the tibia from going forward during midstance to terminal stance
Decreased hip flexion during gait is compensated how?
by circumducting at the hip
If you have weak dorsiflexors what type of gait abnormality can you expect?
Slappage/steppage (severe case)
If you have weak hip abductors what type of gait abnormality can you expect?
Trendelenburg gait
- lateral trunk lean towards side of weakness in order to maintain the body’s COG over the weak side during the stance phase
If you have weak plantarflexors what type of gait abnormality can you expect?
weak pushoff
If you have weak hip extensors what type of gait abnormality can you expect?
lurching
Why do women tend to have less push off and shorter stride length then men?
Their calcaneus are tilted medially (calcaneal valgus) which leads to pronation so they cannot transfer weight from the calcaneus to the great toe
Describe antalgic gait
The stance phase is shortened on the affected side and lengthened on the unaffected side
Common causes of antalgic gait
OA, fractures, tendinitis
4 common compensations of Functional Leg-Length Discrepancy
1) Circumduction
2) Hip hiking
3) Steppage
4) Vaulting
If a patient has inadequate dorsiflexion control due to a weak tibialis anterior or spastic plantarflexors, what gait abnormalities will occur during the stance and swing phases?
During the stance phase the foot will slap the floor. During the swing phase the tow will drag on the floor.
What is Genu recurvatum?
hyperextension deformity of knee
What are 3 common causes of excessive knee extension
- Quadriceps weakness (mid-stance)
- Quadriceps spasticity (mid-stance)
- Knee flexor weakness
Babies that used baby walkers tend to have weakened what?
dorsiflexion power
