GAIT CYCLE- NOTES

Question	Answer
What is the hip flexion requirement for normal gait?	0-30 degrees
What is the hip extension requirement for normal gait?	0-15 degrees
What is the knee flexion requirement for normal gait?	0-60 degrees
What is the knee extension requirement for normal gait?	0 degrees
What is the ankle dorsiflexion requirement for normal gait?	0-10 degrees
What is the ankle plantarflexion requirement for normal gait?	0-20 degrees
What are the muscle activation patterns at initial contact (heel strike)?	Quadriceps(prepares for loading responce) & ankle dorsiflexors, Hamstrings- to extend the hip and prepare for loading responces
What are the muscle activation patterns at the loading response (foot flat)?	pretibial eccentric contraction, , Quadriceps eccentrically to absorb the shock, Hamstrings to extend the hip, Hip ABD stabilize the pelvis in the frontal plane
what are the muscle activation patterns at midstance?	ankle plantarflexors & hip abductors to stabilize the pelvis, hip extensors control forward trunk movement
What are the muscle activation patterns at terminal stance (heel off)?	ankle plantarflexors (concentric), hip adductors, erector spinae
What are the muscle activation patterns at preswing (toe off)?	rectus fermoris acts to restrain rapid knee flexion, momentum enables the femor to fall forward aided by th adductor longus and rectus femoris
What are the muscle activation patterns at initial swing (acceleration)?	pretibial initiate DF, knee flexors, hip flexors, and hip adductors,
What are the muscle activation patterns at midswing?	pretibial mm, Knee Ext. by momentum and gravity,hip flexors, and hamstrings begin to fire
What are the muscle activation patterns at terminal swing (deceleration)?	pretibials, Quads concentricly to ensure the full knee extension, Hamstrings active eccentricaly to decelerate, Gluteus max and Add. longus prepare the leg for the WB
What is the average BOS of an adult?	2-4 inches
What is the cadence for an average adult?	110-120 steps/min
What is the average degree of toe out for an adult?	7 degrees
How much does the pelvis rotate during the gait cycle?	8 degrees (4 degrees forward with the swing leg and 4 degrees backward with the stance leg, to maintain the balance thorax moves towards the opposite side. Helps to regulate speed of walking
What are the energy costs of walking?	Oxygen rate (comfortable pace): 12ml/kg x min & 5.5 kcal/min (level surfaces, depending on surface and body weight)
What increases energy costs of walking?	age, abnormal gait, use of assistive devices
When is the peak activity of the tibialis anterior during the gait cycle?	After initial contact (heel strike): Responsible for eccentric plantarflexion
When is the peak activity of the gastroc-soleus group during the gait cycle?	During late stance phase: Responsible for plantar flexion during toe off
When is the peak activity of the quadriceps during the gait cycle?	During periods of single support in stance phase and before toe off to initiate swing phase
When is the peak activity of the hamstrings during the gait cycle?	During late swing phase: Responsible for decelerating the unsupported limb
How much lateral pelvic shift (PELVIS LIST) occurs during the gait cycle and which muscle group controls it?	side to side movement of the pelvis, necessery to center the weight of the body over the stance leg,2.5-5 cm and facilitate function of hip adductors. Necessary for balance and control lateral movement of COG
What effect does increased cadence have on the gait cycle?	shorter step length, decreased duration of double support (running occurs when double support disappears, at about 180 steps/min)
what mm works together to shorten the stance limb in midstance (control the rise of COG)	Knee Flex, DF, and subtaler pronators
what mm works together to lengthen the stance limb	Knee Ext. PF, and subtalar supinators
how much is the vertical displacement of COG	less or equal to 5 cm total motion 2'
what is the horizontal displacement of COG	2.5 - 5 cm total motion
where is the COG	5 cm antrior to the S2 vertebrae
what is the normal stride length	70-82 cm
Vertical Pelvis Shift	keeps the COG from moving up and down more than 5 cm during normal gait , the High point occurs at midstance and the low point during initial contact
Torque on ankle at initial contact	Ground contact posterior to the ankle joint center creates a planter flexion torque
Torque on knee at initial contact	A brief extension torque occurs
Torque on hip at initial contact	A rapid, high intensity flexion torque begins
Torque on ankle at loading response	Planter flexion torque quickly forces the foot to the floor, and then diminishes in late loading response
Torque on knee at loading response	A flexion torque is caused by the heel rocker action and the position of the body behind the foot
Torque on hip at loading response	A high intensity flexion torque is present(second highest during gait cycle) and an adduction torque begins
Torque on ankle during mid stance	A markedly increasing dorsiflexion torque occurs
Torque on knee during mid stance	the forward momentum created by the contralateral swing limb produces an extension torque.
Torque on the hip during mid stance	The contralateral swing limb moves the body past the stance limb leading to a change from a flexion to an extension torque. The adduction torque continues.