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157 Cards in this Set
- Front
- Back
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What are the two axises of motion of the first metatarsophalangeal joint?
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transverse (horizontal) and verticle axis
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what does the transverse axis of the MPJ joint allow to happen?
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sagital plane motion, dorsiflexion and plantarflexion.
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What does the verticle axis of the MPJ allow to happen?
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transverse plane motion - adduction and abduction
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MPJ normally doesn't have what kind of motion?
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frontal plane motion (transverse is also possible, but is normally controlled by muscles)
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What is the ROM of the First MPJ
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65-75 degrees. dorsiflex 20-30,
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how much additional dorsiflexion of the MPJ must occur for required propulsion by plantar flexing the the first metatarsal?
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45 degrees
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How does the first MPJ achieve 65 degrees?
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tibia is angled at 45 degrees, foot plantar flexed at 20 degrees.
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what pathology involves not being able to get at least 65 degrees of dorsiflexion of the MPJ?
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Hallux limitus
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what are the articulations of the first ray?
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1st metatarsal with med. cuneiform and 2nd metatarsal. medial cuneiform with navicular, intermediate cuneiform and second metatarsal.
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What happens as the first ray dorsiflexes?
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it inverts
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what happens as the first ray plantarflexes?
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eversion
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Why must the first ray be able to dorsiflex?
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remove excess stress from the sesamoids during forefoot loading and to comensate for eversion of the calcaneus during contact period pronation.
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why must the first ray plantar flex?
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to allow propulsion, and to remain in contact with the ground as the forefoot loads from lateral to medial.
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what does the 5th ray closely mirror?
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the subtalar joint axis, motion at the subtalar joint greatly effects motion of the 5th ray axis
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what accompanies dorsiflexion of the fifth ray?
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abduction and eversion
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what accompanies plantarflexion of the 5th ray?
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adduction and inversion
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what joints create the midtarsal joint?
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talo-navicular and calcaneo-cuboid
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What plane of motion will dominate in the longitudinal midtarsal joint axis?
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frontal ( transverse is only 15, sagittal is only 9)which allows for inversion and eversion of the forefoot.
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What planes of motion predominate at the Oblique midtarsal joint axis?
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sagittal (57) and transverse (52)allowing abduction and adduction, dorsiflexion and plantarflexion
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Longitudinal midtarsal axis allows inversion of the forefoot as what happens?
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suppination
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Longitudinal midtarsal axis allows eversion of the forefoot as what happens?
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pronation
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Oblique midtarsal axis allows adduction and dorsiflexion of the forefoot to occur as what happens?
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suppination
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Oblique midtarsal axis allows abduction and plantarflexion of the forefoot to occur as what happens?
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pronation
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how does the forefoot compensate for eversion of the rearfoot during contact period?
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forefoot inversion by suppination at the longitudinal midtarsal axis
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what is the minimum ROM of the longitudinal axis od the midtarsal joint?
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4-6 degrees
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What does the ROM of the longitudinal axis of the midtarsal joint allow to compensate for
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subtalar joint pronation
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which joint is the most important to influencing foot function?
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subtalar joint
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what is the average subtalar axis angles?
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42 transverse, 16 sagittal, 48 frontal
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what are the movements of the subtalar joint?
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pronation and suppination
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what two planes does the subtalar joint mostly move in?
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frontal and transverse
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what is the minimum ROM of the subtalar joint to have normal funtion
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8-12 degrees frontal planre motion. (Normal ROM is 30 degrees, 20 inversion and 10 eversion)
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when does the subtalar joint have a slight amount of abduction?
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during dorsiflexion
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when does the subtalar joint have a small amount of adduction?
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during plantarflexion
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what is the minimum ROM of the ankle joint?
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10 dorsiflexion, 20 plantarflexion
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Knee joint motion is primarily in which plane?
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sagittal
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when is the hip extended during gait?
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contact and mid stance periods?
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What is occuring at the STJ, and the knee joint during contact period?
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pronation of the STJ and internal rotation of the knee joint.
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what happens to the STJ and the knee joint during midstance and propulsive period
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STJ supinates, external rotation of the knee.
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what is the difference between motion and position when giving a direction?
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motion is the direction that the object is moving. Position is the location of the object regardless of motion.
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How do you determine which plane of motion the movement is occuring in?
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parellel to the plane of movement.
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what plane does knee flexion occur in?
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sagittal
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what plane does rotation of the foot occur in?
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transverse
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what plane of motion does abduction of the arm occur in?
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frontal
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what are the motions involved in pronation
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eversion, abduction, dorsiflexion
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what are the movements involved in suppination?
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inversion, adduction, plantarflexion
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what is adductus and abductus?
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fixed structural positions of the foot.
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what is varus?
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fixed structural position where foot is inverted parallel to the frontal plane.
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what is valgus?
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fixed structural position where foot is everted parallel to the frontal plane
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what is talipes calcaneus?
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fixed structural position of dorsliflexion above the transverse plane
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what is talipes equinas?
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fixed structural position of plantarflexion below transverse plane.
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what is the relationship of the axis of motion and the plane in which the motion occurs?
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axis of motion is perpendicular to the plane of motion (ex: for the sagittal plane, axis of motion is perpendicular to the sagittal plane).
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What is the definition of the gait cycle?
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interval of time from heel strike to following heel strike of the same foot.
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what is the stance phase of gait?
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the weight bearing portion of the cycle, between heel strike and toe off.
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what is the swing phase of the gait cycle?
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non-weight bearing phase of the gait cycle, from toe off to heel strike.
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what makes up most of the gait cycle?
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stance phase (62%)
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describe the motion of the foot during swing phase.
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the foot pronates, then supinates
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what is the significance of pronation during the swing phase of gait?
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shortens the limb to help the foot clear the ground just after toe off, and minimizes energy used for ground clearance.
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what is the significance of suppination during the swing phase of gait?
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stabilizes the osseous structure of the foot, preparing it for heel strike.
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what are the 3 periods of stance phase?
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contact (27%), midstance (40%), propulsive (33%)
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when does the contact period occur during the stance phase of gait?
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between heel strike of one foot and toe off of opposite foot.
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When does forefoot loading occur in the foot?
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at the end of the contact period, when toe off is occuring on the other foot.
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when does midstance period occur in the stance phase of gait?
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after contact period, after toe off of opposite foot, ends with heel lift of observed foot.
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when does propulsive period occur in the stance phase of gait?
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after midstance period, begins with heel lift and ends with toe lift of the same foot.
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what is the position of the foot when heel strike occurs?
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suppinated
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what happens to the subtalar joint at the start of weight bearing and during the contact period?
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subtalar joint pronates to absorb shock, and adapt to the terrain.
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What happens to the subtalar joint from midstance through propulsion?
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subtalar joints supinates.
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what happens to the leg during propulsion?
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externally rotates
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What happens to the foot when the subtalar joint suppinates during the midstance period?
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the foot changes from a mobile adaptor to a rigid lever by piling the bones upon one another, which allows for more efficient propulsion and maximal efficiency of the muscles in the leg.
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What happens to the subtalar joint right before toe off, and causes what to happen?
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pronates slightly, causing the weight to shift from lateral to medial foot (Hallux and 2,3 metatalrsal heads).
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what is the most important part of the foot during propulsion?
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hallux
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What happens if the subtalar joint is pronated during propulsion?
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fatigue of foot and leg muscles, leads to muscle imbalances, can cause calluses and deformities
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What are the normal planes of motion for the first ray axis?
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frontal and sagittal, transverse is clinically insignificant
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When does the knee flex and extend during the swing phase of gait?
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knee flexes during contact period, extends at beginning of midstance until right before heel lift, flexes aagin right before and through propulsion.
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describe the motion of the upper trunk in contrast to the pelvis motion during gait.
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opposite. when pelvis internally rotates, upper trunk externally rotates, and vis versa.
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What is inertia?
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tendency of something to remain at rest.
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what is newton's first law?
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net moment acting on a mass is equal to the moment of inertia times the angular acceleration
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what is newton's second law?
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force equals mass times acceleration
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what is newton's third law?
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to every action there is an equal and opposite reaction
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what is the point of acceleration of resistence?
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insertion of the muscle
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what is Effort?
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the vector, or direction the muscle contracts
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What is the Effort arm?
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distance from the axis of rotation to the point of muscle attachment
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What is the point of acceleration of resistence?
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center of gravity pf the mass of the lever, the more mass, the greater the distance
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What is Resistance?
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force in the opposite direction.
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Resistance arm?
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distance from the axis of rotation to the resistence vector
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What are the differnces between class I, II, and III levers?
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I and II only cross one joint. Class II originates from the moving component. Class III crosses more than one joint.
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what is a positive lever mean?
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Effort arm is greater than the resistant arm, characteristic of class II levers, magnifies force.
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what is a negative lever
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resistant arm is greater than the effort arm. Class I, and III. magnifies speed.
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What is occuring with the bones during a static stance?
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the bones are moving slowly and slightly. THis moves the bones, causing the muscles to stretch and adjust, which requires muscles to re-establish osseous position to relieve tension on the ligaments.
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What is hypermobility?
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motion in a direction that is outside its normal plane of motion and causes instability.
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What is subluxation?
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partial dislocation
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when is stability higher, during supination or pronation of the foot weight bearing?
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suppination
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what is static stance?
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when all bones of the foot remain near motionless.
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how is body weight support distributed throughout the feet?
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1/4 in the forefoot, 1/4 in the heel, 1/2 in midfoot.
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what is the distribution of body weight in relation to the metatarsal heads.
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2 times the amount on the first metatarsal head, the rest have 1 part.
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what muscle has to fire in order for the metatarsal heads to bear 1/4 of the body weight?
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gastrocnemius, plantarflexar force, and must exceed force of the load of the tibia
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what conditions must be present in order for a person to have a normal distribution of body weight in a static stance?
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1:sagittal bisection of leg and calcaneus is perp. to ground and parallel to eachother.
2: nuetral subtalar joints 3: midtarsal joints are maximally pronated (locked) 4: plantar surface of forefoot rests fully upon ground, all meta heads bear weight. 5: no muscle support needed |
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why does ligament tension provide structural stability during static stance, and not in dynamic gate?
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becuase there isn't enough time for the ligaments to stabalize, the movement is too quick
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what are the two components if force interacting at a joint ?
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compression (stability) and bending (instability)
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when does rotational motion in most joints increase in a normal foot
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during pronation, b/c angles between bones increase
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what are the four roles that ligaments play in the foot?
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1: function during emergency instability
2: decelerate motion of a subluxing joint 3: start contraction of muscels to stabalize the joint 4: keep joint integrity intact until muscles take over |
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what is hypermobility?
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abnormal motion of bone caused by unresisted forces at a time when the joint should be stable
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what are normal compensations?
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onr part of the foot adjusting to any irregularity that is normal to maintain our equilibrium
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what joints usually make normal compensation?
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subtalar (most) and midtarsal joints
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when is the first peak of the verticle ground reactive force seen?
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at the end of the contact period when heel and metatarsals are loaded
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when is the second peak of te vertticla ground reactive force seen?
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midway through the propulsion period when all weight is on the metatarsals
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when is posterior sheer force seen in the gait cycle?
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at heel strike during contact period
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when is anterior sheer force seen during the gait cycle?
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heel lift and push of propulsion
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what happens when the heel contacts the ground and the tibia is internally rotating?
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friction from the ground stops the foot from moving and causes the subtalar joint to pronate
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When is lateral sheer seen in the gait cycle?
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at the end of the contact period and during propulsion
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what directs the medial column
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talus
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what directs the lateral column
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calcaneus
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which column of the foot adapts to the terrain?
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medial column
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which column of the foot is primarilly responsible for balance?
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lateral column
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what is the dominant plane of the OMTJ and why?
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transverse plane because the OMTJ axis is more deviated vertically and the axis is more perpindicualr to the transverse plane
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what is the dominant plane typically seen in flatfooted people?
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frontal plane
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what is the dominant plane normally seen in high arched feet?
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transverse plane
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What happens if the STJ axid in the transverse plane is deviated more medially or laterally?
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medially = more pronation
laterally = more suppination |
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what passive role does the plantar fascia have on the STJ?
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passive suppinator
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what is the windlass mechanism?
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dosiflexion of toes causes medial arch height to increase, inverting the calcaneus.
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why is the passive suppination of the plantar fascia important in gait cycle
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it aids in continued suppination into propulsion
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describe the Elftman explanation of locking position of the midtarsal joint
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both joints have two axis. Pronation, two are lined up, unlocking. Suppination, all four lock it.
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Huson's ideas about the midtarsal joint?
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MTJ = Navicular + Cuboid rotating around Talus and Calcaneus
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Nester's ideas of the MTJ?
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Navicular and Cuboid move as a single unit, only one axis at all times.
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What is the difference between compensated, uncompensated, and partially compensated forefoot varus?
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forefoot varus means head and neck of talus didn't fully evert during growth. Compensated- STJ can evert enough for att MTJ to reach ground but foot pronates into propulsion.
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Equinus - how does it compensate?
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can't dorsiflex foot 10 degrees at midstance period - pronation at heel @ contact, flexed knee, early heel off.
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forefoot valgus
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excessive torsion of head and neck of talus, compensate = dorsiflexion of 1st ray or by suppinating the STJ.
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If the foot is compensating for forefoot valgus by dorsiflexing first ray, how is this seen?
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lesion under MPJ 2
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If the foot i compensating for forefoot valgus by suppinating the STJ, how is this seen?
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lesion under MPJ 1 or 5
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what is young's modulus?
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stress/strain = elasticity
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what is hook's law
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as stress increases, so does strain proportionatley
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what is the yield point?
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when the material can no longer resist the load upon it
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what is a failure point?
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when the material can no longer perform its function in response to the load
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what is anisotropic mean?
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not having properties the same in all directions
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what type of force is bone most resiliant to? least?
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compression and tension. least = torque, or sheer.
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what is the difference between direct and eccentric loading?
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direct (concentric) is straight down in the center. Eccentric is loading not down the center.
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what is wolff's law?
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bone adapts and alters its structure in response to stress
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what is davis's law?
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same as wolff's, but for soft tissue, which adapts and is altered much faster
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what types of stresses result in bone absorption?
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positive electric current, convex stress
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what type of stresses result in bone formation?
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negative electric current and compression
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what is the relationship of compression to tension in muscles?
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as muscles compress during contraction, tension decreases
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what are the muscles involved in stabalizing the foot bones during midstance?
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soleus, fibularis longus, tibialis posterior, fibularis brevis
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how are the 2nd 3rd and 4th rays stabalized during midstance?
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beginning - intrinsic mucscles resist dorsiflexion, and aided by the flexor digitorum longus and the tibialis posterior
later - aided by quadratus plantae and lumbricales |
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what muscles provide transverse stability to the inner rays during midstance?
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tibialis posterior and soleus
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what stabiliozes the first ray adn what direction?
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fibularis longus - in a plantar posterior and lateral direction, abducttor hallucis and flexor hallucis longus help
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what muscles cause subtalar joint suppination?
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tibialis posterior, soleus, long digital flexors
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what muscles resist suppination of the subtalar joint supination?
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fibularis brevis and longus
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what takes place during swing phase to help the foot clear the ground
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the foot pronates, which functionally shortens the limb, and slight dorsiflexion of the foot.
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what takes place during swing phase, the latter part, to prepare the foot to contact the ground?
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the foot supinates, functionally lengtheing the limb.
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what is taking place in the leg during swing phase?
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at the beginning of thw swing phase, the leg is externally rotating, but ashortly after it begins internally rotating.
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when is the only time that pronation of the sunbtalar joint should be seen in the foot?
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during the contact period
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how is closed kenetic chain pronation described at the subtalar joint?
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eversion of the calcaneus, adduction and plantarflexion of the talus
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the foot becomes a mobile adaptor and has a reduction in shock becuase of what occuring at the subtalar joint?
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pronation of the subtalar joint and also felxion fo the knee joint.
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what is happening in the hip during the contact phase of gait cycle?
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hip is extending and internally rotating, thigh is internally rotaing faster than the pelvis.
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what is happening at the ankle joint during the contact period.
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plantarflexion and adduction
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why is the contact period and propulsive periods known as a double limb support
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both limbs are touching the ground
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supination of the LMTJ axis at heel strike is caused by what muscle?
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anterior tibialis
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pronation of the OMTJ axis at heel strike is caused by what muscles?
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extensor digitorum longus and fibularis tertius
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