general q.61-122 Flashcards
Why doesn’t tibialis anterior and extensor hallucis longus help with dynamic stability of the medial arch?
they work anterior the the axis of sagital plane motion creating DF which flattens the medial longitudinal arch
What role do the calcaneonvicular ligaments play in stability of the medial longitudinal arch?
- the are the primarly stabilizers
2. without the spring ligament the arch will collapse
What makes up the lateral longitudinal arch?
- calcaneus
- cuboid
- lateral tow metatarsal bones
what is the function of the lateral longitudinal arch?
- transmit weight and thrust
2. it does not participate in shock absorption
what bones make the transverse arch and what are its dynamic stabilizers?
- cuneiforms and cuboid
- fibularis longus- passing under the cuboid to the base of the 1st met and medial cuneiform
- fibularis brevis- attaching to the base of the 5 metatrasl
why is the subtalar joint so important to the gait cycle?
- it lies within the vertical column of the leg and functions like a universal joint transferring force to the forefoot
- it also modifies the mobility of the other joints of foot
how does the talus normally move on the calcaneouis during closed chain pronation?
- anterior glide
- plantar flexes
- adducts
How does the subtalar joint transmit force from the ankle to the foot?
1the foot si slightly ER (20 degrees) at intitial contact
- as the foot pronates in response to loading stability of the talus is decreased
- lost of stability allows the talus to IR bringing the ankle with it and flexing the knee
- IR of the subtalar joint unlocks the mid and fore foot for dampening of GRF
How does the subtalar joint control the mobility of the midtarsal joints?
- pronation of the subtalar joint brings the axis of the talonavicular and calcaneocuboid joints parallel to each other so the hinges of the door line up and can move
- supination fo the subtalar joint causes a divergence of the midtarsal joints and locks them along with the tarsal into a relatively PF’d postion
What three actions are necessary to initiate walking?
- weight shifts towards the limb to be lifted
- weight is transfered towards the stance limb
- wieght moves forward as the body is allowed to fall forward and swing leg is lifted
What muscles are activated to initiate gait?
- in the swing leg tibialis anterior contracts to pull the tibia forward
- once the tibia passes over the axis of the tolocural joint the soleus works eccentrically to control forward motion
- ankle ankle DF and hip flexors also kick in
What are the foot rockers?
- different axis of motion through the stance phase
- heel-during loading the weight is on the heel until foot flat
- ankle- once the foot is flat motion shifts to the ankle
- metatarsal heads- as the heel lifts the axis shifts to the metatarsal heads
how does the body minimize energy loss during gait?
- it takes steps to limit shifts in center of gravity side to side or up and down
- the pelvis and legs perform theses adjustments
How do the lower extremities control shifts in center of gravity during gait and why is this important?
- heel rise at terminal stance equalizes leg lengths
- full knee extension at IC for the same reason
- it helps conserve energy
How does the pelvis play a role energy conservation during gait?
- contralateral hip drop
- horizontal rotation
- lateral displacement
What is the role of the subtalar joint during gait?
- the action of the subtalar joint dictates the function of the foot (adaptation, shock absorption, propulsion)
- pronation of the subtalar joint IR the tibia causing flexion of the knee
What is the role of the knee during gait?
- flexes during LR to dampen GRF
- extends mid to terminal stance
- flexion during swing to clear foot
- extends for IC to equalize leg length for energy conservation
At heel strike what is the position of the femur, knee, patella, tibia, talus, subtalar, calcareous, tarsals, metatarsals, MTP joints?
- femur- IR
- knee- extended
- patellar- lateral-superior
- tibia-ER
- talus-supinated
- subtalar-valgus
- calcaneous-pronated
- tarsals-lateral to medial shear
- metatarsals-tansverse arch decreases
- MTP joint- no action
At mid stance what is the position of the femur, knee, patella, tibia, talus, subtalar, calcareous, tarsals, metatarsals, MTP joints?
- femur- ER
- knee- flexed
- patellar- eccentric compression
- tibia-no action
- talus-anterior angle
- subtalar-varus
- calcaneous-supinated
- tarsals-medial arch flattens
- metatarsals-spread out
- MTP joint- no action
At toe off what is the position of the femur, knee, patella, tibia, talus, subtalar, calcareous, tarsals, metatarsals, MTP joints?
- femur- IR
- knee- extended
- patellar- lateral-compression
- tibia-no action
- talus-relatively pronated
- subtalar-
- calcaneous-
- tarsals-increased in transverse arch height
- metatarsals-first met ER
- MTP joint- passive extension
What is the shape of the proximal tib fib joint surfaces and what is its relative location?
- plane joint on the fibular surface
- tibia slight convex facet on the posterior lateral surface
- oriented posterior, lateral, and inferior
What does the capsule of the proximal tib fib joint look like?
- fibrous capsule attaching to the rim of the facet on the tibia
- 10% of the population it communicates with the tibiofemoral joint
What are the ligaments of the proximal tib/fib joint
- anterior- oblique orientation from the fibular head to the tibial condyle
- posterior- oblique oreintation from the fibular head to the lateral tibial condyle
- LCL
What are the ligaments of the distal tim/fib joint?
- interosseus- a continuation of the interosseus membrane
- anterior tibiofibular
- posterior tibiofibular
What joint has the greatest impact on the movement of the tib/fib joints?
1.the ankle
How does active movement of the the tim/fib joint occur?
- its primarily a passive joint and reactive to the movement of the ankle
- biceps femoris can move the proximal tim/fib
What are the motions of the proximal and distal tib/fib joint?
- supination- fibular head moves distally and posterior
- plantar flexion- fibular head move distal and IRs
- dorsi flexion- fibular head glide proximally and ER
- distal will compress during PF and separate during DF
how will inadequate DF influence IC?
1decreased heel rocker results in a rapid drop of the foot
2.a deformity of 20 degrees with put the foot flat at IC
How will inadequate DF influence mid stance?
- trunk can flex
- genu recurvatum
- premature heel off
How will inadequate DF influence terminal stance?
- excessive heel rise may not show a deviation
- there may be exessive knee extension
- trunk will side ben towards the side of limitaiton
how will inadequate PR influence gait?
a weak soleus will have difficulty controlling the tibia’s advance over the ankle forcing the knee to flex
How will a VARUS rear foot position influence the gait pattern?
- IC- the lateral contact of the heel will cause increased range and speed of pronation as you move into a “pronated” position
- MS- heel rises early because the tibia did not sufficiently IR and will pull the heel up too soon
- TS- forefoot must bring the rest of the foot to the ground in a valgus position
How will a VALGUS rearfoot position effect the gait?
- IC- medial calcaneous is loaded so there is a decrease in the surface area for loading
- MS- increased and late pronation keeps the foot flexible too long and increase tension through the plant fascia as the toes start to flex
- TS- continuation of MS
Dysfunctional foot mechanicas will have what functional impacts?
- the amount of motion it too large
- the speed of the motion is too great
- the timing or sequence of the joint motion is incorrect
What is rear foot varus and what biomechanical problems result?
- calcaneous is in an inverted postion
- lateral condyle of the calcaneous contacts the ground first
- the calcaneous pronates early and fast to bring the medial condyle to the ground
What are the some correlated motions associated with rear foot varus? compensations?
- tibial ER
- tibial IR, hallux valgus, PF first ray, forefoot valgus, execessive or prolonged midtarsal pronation, knee vlagus, lateral patellar tracking if tibia stays ER’d, anterior pelvic tilt, lumbar extension
What is the callus formation with rearfoot varus?
- typically along the met heads except for the first
2. pinch callus on greater toe from pushing of an abducted foot
How can a rearfoot varus lead to a PF first ray?
- the rapid and excessive pronation can cause the fibularis longus to lose first ray stability
what is forefoot varus and what biomechanical problems result?
- inversion of the forefoot of the rearfoot in subtalar neutral
- the foot must excessively pronate to bring the first ray to the ground
- late pronation means insufficient locking for the mid foot for propulsion
What are the correlative motions and possible compensations for forefoot varus?
- subtalar supination
- PF first ray, hallux valgus, hypermobile first ray, excessive or prolonged pronation, excessive IR rotation of the LE with contralateral IR of the spine
What is the callus formation for forefoot varus?
callus under the second met head since the lateral foot will lift off the ground and the weight shifts medially
What is forefoot equinus?
forefoot is plantar flexed relative to the rear foot, not just the first ray
What are some potential compensations for forefoot equines?
1.hypermobilie first ray
2.subtalar or midtarsal excessive pronation
3.early hip or knee flexion
4.genu recurvatum
5increased talocural dorsiflexion
Where do you get a callus with forefoot equinus
- first met head since it takes most of the force
2. fifth met head since it will hit hard because the mid foot cannot unlock at the proper time
What biomechanical conditions lead to plantar fasciitis and talar exostosis?
- forefoot varus leading to late supination for locking mid foot resulting in excessive PF tension with the windless mechanism
- Exessive DF during from forefoot equines can lead to exostosis
What is a plantar flexed first ray and what problems do you have to over come?
- first ray is plantar felxed realtive to the other metatarsal
- if the first ray is stuck in PF you are unable to achieve adequate hallux extension with gait because you need to have additional PF of the first ray and it is already maxed out.
What is forefoot valgus and what problems must be overcome?
- eversion of the forefoot relative to the rear foot in subtalar neutral
- early supination because to forefoot contacts the ground early and force the directional change
What are some possible correlated and compensatory motions of forefoot valgus?
CORrelated
1.hallux valgus
2.subtalar pronation and kinetic change IR
COMpesatory
1.excessive or prolonged subtalar or midfoot supination
2.exessive LE ER with ipsalateral spinal rotation
what is pes plans and its biomechanical impact on the foot?
- abnormally pronated foot with calcaneous subluxing under the talus
- calcaneous is everted
- nvicuar tuberosity is rotated down
- forefoot is abducted relative to the rear foot
- height of the arch is reduced
What orthotic modification would you make with hallux limits?
metatarsal bar
how would you differentiate between PF, calcaneal spur and heel bruise
- tenderness- PF calcaneal WB surface; HS distal medial calcaneous; HB surface of calcaneous
- estension of MTPs- PF pain; HS pain; HB no pain
- heel walking- PF no pain; HS may increase pain; HB pain
- toe walking- PF pain; HS pain; HB no pain
- radiology- PF negative; HS postivite; HB negative
What is a march fracture?
stress fracture of the second and third metatarsal
What are the typical clinical features of a plantar digital neuroma (6)?
1.swelling usually about a one centimeter in length
2.peircing pain with numbness or tingling
3symptoms may increase with standing or walking
4.symptoms may improve with taking shoe off and working with foot
5.decrease in transverse arch of the foot
6.pain with pressure between met heads
What is congenital club foot?
the deltoid ligament develops myofibroblast like cells creating shortening of the collagen pulling the foot into a dysfunctional inverted position
What are some predisposing factors to ahcilles tendonitis?
- overuse with runners or recreational athletes
- forefoot varus or excessive pronation
- limited dorsiflexion
- hypomobility of the subtalar joint
what is the chemical involved in gout?
elevated uric acid
What conditions can contribute to neuropathic arthritis of the foot?
- tabes dorsalis
- diabetic neuropathy
- syringomyelia
- charcot Marie tooth
What is tabes dorsalis?
a slow degeneration and demylination of the sensory neurons and dorsal column
What is syringomyelia?
a generic term referring to a disorder in which a cyst or cavity forms with in the spinal column
What is os trigonum?
- an accessory bone found on the posterior lateral talus
2. present in 2.5-14% of population
What is Kholer’s disease?
- a temporary softening of the navicular bone in children 3-5 years old
- possibly the result of disturbances of blood flow
What is tarsal coalition?
fusion of two or more tarsal bones
What is tarsal tunnel syndrome?
compression of the posterior tibial nerve under the laciniate ligament or lfexor retinaculum at it passes below the medial malleoulus
What are the clinical findings of tarsal tunnel syndrome?
- pain and burning on the bottom of the foot
2. positive tinel’s
What are some indicators for orthotics?
- execessive motion
- insufiecent motion
- excessive tibial ER
- abnormal torque conversions- decreased ability to transmit rotational forces into propulsion forces
- postural sway
- leg length differences
what are contraindications for orthotics?
- blocking pronation with a lack of DF because you are blocking the compensation for the loss of DF
- blocking shock absorption in the presence of OA, tarsal coalitions or boney blocks
What is the greatest amount of medial wedge and why?
5 degrees
- normal motion is about 4 degrees for shock absorption
- you cannot block all the motion because you need some for shock absorption
What is the difference between intrinsic and extrinsic posting?
- intrinsic is built into the shell
2. extreinsic is added to the shell
What is a THomas heel?
a varus wedge built into the sole of the shoe to help control pronation
What factos are associated with injury rates of runners?
1.older age
2.smoking
3.sedentary life style or work
4.high or low flexibility
5.high arches
6high or low body fat
7.increased milage
