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Gait Cycle NGU Kinesiology

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aacilla's version from 2017-08-15 03:16

Section 1

Question Answer
What are the two main phases of gait cycle?Swing and Stance Phases
What are the four subparts to stance phase?Initial contact, loading response, midstance, terminal stance
What are the four subparts to swing phase?preswing, initial swing, midswing, terminal swing.
memorize

Initial Contact

Question Answer
What percentage of the GC does IC make up?0-2%
What is the Objective of IC?Initiate foot rocker and Impact deceleration
What is phase is the contralateral foot in?End Terminal Stance
What is the healthy ankle position in initial contact?0ยบ -Neutral
What controls the foot positioning in initial contact?Anterior Tibialis (ecc) dorsiflex ankle
What position is the subtalar joint in during initial contact?Neutral
What position is the knee in during initial contact?Neutral to slightly flexed (0-5 degrees)
What are the knee stabilizers during initial contact?Co-contraction of Quads and Hams
What position is the hip in during initial contact?20 degrees of flexion
What is controlling the hip position during initial contact?The hip extensors (glut max and hams) which are isometrically preventing collapse into flexion
What position is the pelvis in during initial contact?5 degrees of forward rotation.
memorize

IC Forces

Section 2

Question Answer
What is the position of the ankle during loading response?5-10 degrees of rapid plantar flexion
What is controlling the position of the ankle in loading response?Eccentric contraction of the anterior tibialis
True or false, the anterior tibialis is initating forward motion of the tibia to flex the knee, in order to plantar flex the ankle in loading responseTrue!
What is the position of the sub talar joint during loading response?calcaneus eversion 5 degrees, mid tarsal is unlocked allowing foot to pronate.
Why is it neccesary for the foot to pronate during loading response?It allows for shock absorption
What muscles are working eccentrically to prevent foot collapse during loading response?The inverters
What other muscle is firing eccentrically to internally rotate the tibia during loading reponse?The posterior tibialis.
What position is the knee in during loading response?Flexed to about 15 degrees
What muscle is controlling knee flexion during loading response, in order to absorb shock and prevent collapse of the knee?The quads are firing eccentrically.
What position is the hip in during loading response?Flexion.
What muscles are controlling the hip position during loading reponse, and what is their goal in doing so?Hip extensors (glut max and hams) eccentrically firing to counteract high flexion torque in order to stabilize hip and assist hip into extension.
What is the position of the pelvis during loading response?5 degrees of forward rotation and 5 degrees of pelvic drop
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Section 3

Question Answer
What is the ankle position during mid stance?Dorsiflexed about 5 degrees
What is controlling ankle position during mid stance?Eccentrically firing gastroc-soleus, in order to control the forward translation of the tibia.
Where is the ground reaction force in mid stance, and what does it cause the knee to do?It is anterior to the knee, causing the knee to extend without a muscle contraction
What is the position of the sub-talar joint in mid stance?Calcaneus is everted about 5 degrees, mid-tarsal is unlocked and foot is pronated.
What is the reason behind foot pronation in mid stance?Shock absorption
What muscle is firing eccentrically to control the pronation of the foot in mid stance?The posterior tibialis in order to internally rotate the tibia.
What is the FIRST thing to happen to the knee during midstance? (What muscle is firing to put knee in its specific position?)The quads are CONCENTRICALLY firing to assist the knee to move into about neutral.
What assists the move of the knee into neutral during midstance? (HINT it's not a specific muscle)The forward momentum of the contralateral swing limb.
What is the SECOND thing to happen to the knee during midstance, which enables it to stay extended?The ground force reaction moves anteriorly to the knee, which keeps it extended, and allows the quads to stop firing.
What is the stabilizer of the knee during midstance after is is extended?The gastroc soleus complex eccentrically controls it.
Where are ground reaction forces at the end of mistance?anterior to the knee and posterior to the hip!
True or false, muscle activity is required at the knee and the hip at the end of mid stance.False-the ground force reaction is naturally controlling them.
What is the position of the hip during midstanceHip extension
What is controlling hip position at midstance?Ground force reaction (No glut max or hamstring firing once the GRF falls posteriorly to hip joint.)
What is the position of the pelvis during mid stance?Backward rotation to neutral.
memorize

Section 4

Question Answer
What is the ankle position during terminal stance?Heel rises, dorsiflexion by about 10 degrees.
What muscle is eccentrically contracting to prevent tibial collapse during dorsiflexion of the ankle in terminal stance?Gastroc-soleus complex
Where has the axis of rotation reached in late terminal stance?Metatarsal heads.
Because the axis of rotation has reached the metatarsal heads in terminal stance, what motion is the forefoot going through?Forefoot rocker
In late terminal stance the dorsiflexion of the foot (increases/decreases)?Decreases, to a halt.
In late terminal stance, which muscle switches to concentric to stabilize the ankle joint and allow the tibia and foot to roll forward on the forefoot rocker?Gastroc
What percentage of acceleration force is seen in the terminal stance?80% of acceleration force
What is the position (or increase in positioning) of the sub-talar joint in terminal stance?Gradual calcaneal inversion (supination), as the midtarsal joint locks.
What does supination of the foot provide in terminal stance in terms of for movement?A rigid lever for propulsion.
What does the tibia do during terminal stance, as it is being controlled by concentric firing of the posterior tib?Tibia is externally rotating.
Which muscles in the leg provide lateral stability to the foot and leg in terminal stance?Peroneus longus and brevis
The peroneus longus (eccentrically/concentrically) fires as the foot supinates to support the arch and keep the first ray on the ground in terminal stance?Eccentrically
What is the position of the knee in terminal stance?varus and extension
How is the knee joint kept stabilized in terminal stance?By the gastroc-soleus complex
What is the varus motion of the knee stabilized by in terminal stance?Lateral knee and ankle ligaments
What is the position of the hip in terminal stance?Extension by about 20 degrees. Hyperextension.
Hip extension in terminal stance causese (posterior/anterior) tilt of the pelvis?Anterior
What stabilizes the hip in terminal stance?The anterior hip capsule (passive)
What is the position or the continuation of position of the pelvis in terminal stance?5 degrees of backward rotation and anterior tilt. Also, pelvis is neutral in frontal plane.
memorize

Section 5

Question Answer
What is the position of the ankle in preswing?Plantar flexion (due to limb being unloaded and it PF'ing over fixed fulcrum)
Does the Gastroc-Soleus activity increase or decrease in pre-swing?decrease to a cease!
How much is the ankle plantar flexed during pre-swing?15-20 degrees
What is the position of the subtalar joint in pre-swing?neutral
What is the position of the knee in pre-swing?rapid knee flexion to about 40 degrees
How is the knee unlocked to flex during pre-swing?By motion and action at the ankle
In a natural pace, knee flexion is active in pre-swing, T or F?False-passive motion during natural pace.
When walking in a faster pace, which muscles acts to decelerate excessive passive knee flexion in pre-swing?The rectus femoris
When the RF eccentrically fires to deccelerate passive knee flexion (faster pace), where does the energy get transfered to, and what is the purpose of this? in pre-swing.It transfers the energy to the hip to augment hip flexion concentrically.
What is the position of the hip in pre-swing?Neutral or slightly extended, but does fall forward due to momentum and unlocking of the knee.
Which muscle may fire in hip positioning, acting as an energy transfer strap?The rectus femoris,
What is the position of the pelvis in pre-swing?5 degrees of backward rotation and anterior tilt.
memorize

Section 6

Question Answer
What is the position of the ankle in initial swing?Plantar flexion decreases to about 5 degrees.
What muscle concentrically initiates dorsiflexion in initial swing?Anterior tibialis.
What is the position of the sub-talar joint in initial swing?neutral!
What is the position of the knee in initial swing?Flexion to about 60 degrees (for good clearance of the ground!)
In a slower paced walk, which muscles help with knee flexion in initial swing? (they concentrically do this).biceps femoris, gracilis, and sartorius.
What is the position of the hip in initial swing?flexed about 15 degrees
Which muscle is primarily responsible for the hip positioning in initial swing?Iliopsoas (concentrically firing)
What is the position of the pelvis in initial swing?5 degrees of backward rotation, and rotated posteriorly.
memorize

Section 7

Question Answer
What is the position of the ankle in mid swing?dorsiflexed to neutral (0 degrees) achieving foot clearance off the ground!
Which muscle controls the ankle and foot positioning, and does it fire eccentrically or concentrically?Anterior tibialis, concentrically!
Common belief that anterior tibialis actually falls silent in this phase of mid swing, true or false?True
What position is the sub-talar joint in during mid swing?Neutral.
What position is the knee going into during midswing?Extension up to 25 degrees.
The motion of the knee going into it's position in mid swing is caused by what force?MOMENTUM! No muscle activity is required.
What position does the tibia obtain during knee positioning in mid swing?Vertical!
What is the position of the hip during mid swing?25 degrees of flexion
At the end of the hip positioning in mid swing, does hip flexor action continue to go on, or cease?CEASE!
What is the position of the good ol pelvis during mid swing?Forward and posterior rotation to neutral.
memorize

Section 8

Question Answer
Ankle positioning in terminal swing?it remains in neutral!
Is the anterior tibialis active or passive in this terminal swing phase, and why?active in order to pre position the foot for initial contact! (preparing to land!)
What is the sub-talar joint position in terminal swing?Neutral
What is the knee position in terminal swing?Extension to neutral.
Which muscles are controlling the knee positioning in terminal swing?Hamstrings to deccelerate the thigh and leg movements into extension, by eccentric firing.
Which muscles are preparing the knee for initial contact in terminal swing phase?The quads (concentrically)
What is the hip position in terminal swing?Hip flexion like mid swing.
Which muscles are preparing the stabilization of the hip during weight acceptance in initial contact?The hamstrings (eccentrically deccelerating the thigh) and the glut max (initialting activity)
What is the position of the pelvis in terminal swing?5 degrees of forward rotation.
memorize

Section 9

Question Answer
Ankle plantar flexion contracture is inability to dorsiflex beyond how many degrees of PF?15 degrees
Knee flexion contracture-inability to fully extend beyond _________ degrees of KF?30 degrees
Hip flexion contracture-inability to fully extend hip beyond ___ degrees of HF?30 degrees
What is a motor disorder characterized by a velocity dependent to increase in tonic stretch reflexes resulting from hyperexcitability of the stretch reflex?Spasticity
Spasticity is usually only an issue when?Muscle is stretched during gait.
Increase in muscle tone that causes an increased resistance to passive stretch.Hypertonia
What is forefoot contact?Initial contact with the forefoot
What is foot-flat contact?Initial contact with the entire foot
Foot flat?Uncontrolled PF at initial contact
What is heel off?heel not in contact in loading response or mid-stance
What is no heel off?absence of heel raise in terminal stance or pre swing.
what is drag?contact of foot or toes in swing phase
What is contralateral vaulting?PF or rising on forefoot of opposite stance limb for clearance of reference leg.
memorize

Section 10

Question Answer
What are the likely causes for forefoot or foot-flat contact in weight acceptance?secondary excess knee flexion in term-swing, secondary excess PF in term-swing, compensatory for weak quad to avoid loading response.
What is the likely cause for foot slap in weight acceptance?weak anterior tibialis.
What is the likely cause for excess dorsiflexion in weight acceptance?secondary excess hip or knee flexion
What is the likely cause for excess dorsiflexion in single leg stance?weak gastroc/soleus and secondary excess hip or knee flexion.
What is the likely cause for excess plantar flexion in weight acceptance and single leg stance?secondary weak quads (keep knee extended), PF contracture, or PF hypertonicity.
What is the likely cause for excess PF in single leg acceptance?PF contracture, PF hypertonicity, weak anterior tib.
What is the likely cause for excess inversion in weight acceptance and single leg stance?anterior tib or posterior tib overactivity
What is the likely cause for excess inversion in single leg acceptance?decrease in selective control of anterior tib, peripheral nerve injury-weak peroneals.
What is the likely cause of excess eversion in weight acceptance and single leg stance?weak posterior tib, valgus deformity, PF contracture (only SLS)
True or false, excess eversion can be used to gain plantar flexion range when ankle mobility is limited.False-it can gain dorsiflexion.
What is the likely cause of heel off during weight acceptance and single leg stance?secondary excessive PF, contracture.
What is the likely cause of no heel off during single leg acceptance?secondary excessive dorsiflexion, weak gastroc/soleus, ankle or MT head pain.
True or false, no heel off has no significance on step length.False, it can decrease step length.
What are the likely causes of drag on single leg acceptance phase?pf contracture, pf hypertonicity, weak ant. tib, secondary limited hip and knee flexion, or excess PF.
What are the likely causes of contralateral vaulting in single leg acceptance phase?compensatory to aid clearance of opposite limb.
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