Week 5 Flashcards
Describe the angle of inclination of the hip and coxa valga/coxa vara
coxa valga - > 125 degrees
coxa vara - < 125 degrees
Describe the angle of torsion and list norms
- Between axis through femoral head/neck and the distal femoral condyles
- norm = 8-20 degrees
What is excessive anteversion and how might that impact an individual’s hip?
- increased angle of torsion
- reduces hip stability
- increased hip IR and decreased ER
- pigeon toeing
- commonly found w/ coxa valga
What is retroversion of the hip and how might that impact an individual’s hip?
- decreased angle of torsion
- increased hip ER and decreased IR
- may cause impingement
What is the center edge angle? List the norm and abnormal positions of center edge angle.
- measurement of acetabular depth, amount of space covered from acetabula (roof)
- norm = 25-35 degrees
- > 45 degrees =coxa profunda
- <16 degrees = dysplasia
What is Cam deformity as it relates to Femoral acetabular impingement (FAI)?
- extra bone at anterior-superior region of femoral head and neck junction
- loss of natural tapering of femoral head
- impingement occurs of bulge of femoral head against acetabulum
- IR w/ flexion maximizes impingement
What is Pincer deformity as it relates to Femoral acetabular impingement (FAI)?
- Abnormal bony extension of anterior–lateral rim of acetabulum
- Often associated with deep acetabulum or overly retroverted acetabulum
- Flexion and IR causes premature abutment of femur against acetabulum
What is the position of maximal bone congruency for the hip?
articular congruence - flexion, abduction, slight ER
What are the ligaments of the hip?
- iliofemoral ligament
- pubofemoral ligament
- ischiofemoral ligament
What is the function of the iliofemoral ligament?
- anterior stability
- limits IR and ER
- tighten w/ extension
What is the function of the pubofemoral ligament?
- limits ER in hip extension
- tighten w/ extension
What is the function of the ischiofemoral ligament?
- primary restraint to IR
- tighten w/ extension
What is the function of the transverse acetabular ligament?
- protect blood vessels that travel beneath it to get to the head of the femur
What is the function of the acetabular labrum?
- deepens concavity
- seal to maintain negative intra-articular pressure
What is the function of the ligamentum teres?
- conduit for blood supply to the femoral head
What are the osteokinematics of hip in OKC?
- flexion/extension
- abduction/adduction
- ER/IR
What are arthrokinematics of hip flexion/extension in OKC?
Convex on concave
Flexion
- superior roll and inferior glide (anterior roll and posterior glide)
Extension
- Inferior roll and superior glide (posterior roll and anterior glide)
What are arthrokinematics of hip ab/adduction in OKC?
Convex on concave
Abduction
- Superior roll and inferior glide
Adduction
- Inferior roll and superior glide
What are arthrokinematics of hip IR/ER in OKC?
Convex on concave
IR
- medial roll and lateral glide
ER
- lateral roll and medial glide
What are osteokinematics of pelvis in CKC?
- anterior/psoterior pelvic tilt
- lateral tilt
- Forward/backward rotation
Anterior and posterior tilting produces what motions at the hip?
anterior tilting - hip flexion
posterior tilting - hip extension
What are arthrokinematics of pelvis during anterior/posterior tilting in CKC?
concave on convex
Anterior tilting
- anterior roll and anterior slide
Posterior tilting
- Posterior roll and posterior slide
What are arthrokinematics of pelvis during abduction/adduction in CKC?
concave on convex
Abduction
- superior roll and superior slide
Addiction
- Inferior roll and inferior slide
What motion occurs at the left hip during right pelvic hiking?
hip abduction
What motion occurs at the left hip during right pelvic drop?
hip adduction
What are the arthrokinematics of forward/backward rotation of pelvis in CKC?
concave on convex
Forward
- anterior roll and anterior slide
Backward
- posterior roll and posterior slide
What motion occurs on the stance limb during forward/backward rotation?
Forward - IR of stance joint
Backward - ER of stance joint
Describe the closed pack, open pack and capsular pattern of the hip
closed pack - full extension w/ slight IR and abduction
open packed - moderate flexion, slight abduction, neutral rotation
capsular pattern - IR = flexion = abduction
If someone performs a straight leg raise (SLR) and they demonstrate excessive anterior tilt of the pelvis, what may this indicate?
weak abdominals due to force coupling
Describe the role of the adductor longus in sagittal plane motion.
during hip flexion - contributes to hip extension
during hip extension - contributes to hip flexion
Describe the force required of the hip abductors to maintain a stable pelvis in SL stance
Hip abductor force must work twice as hard to prevent pelvic from dropping due to gravity because hip abductor moment arm is 1/2 the length of joint reaction force
If a patient has R hip pathology resulting in weakness of the R hip abductors what side should we recommend the use of a cane to decrease joint forces in the R hip with single leg stance and why?
left side to increase the moment arm and offset the hip muscles that need to do twice as much work to resist gravity
How can we maximize stretching the hamstrings by cueing an individual to tilt the pelvis? What direction of pelvic tilt enhances a hamstring stretch?
anterior tilting of pelvis to stretch hamstrings
- can also add a slight lean forward with neutral back
What is considered to be normal genu valgum? Excessive genu valgum? Genu varum?
Normal - 170-175 degrees
Genu valgum - <165 degrees
Genu varum - >180 degrees
Which area of the knee receives greater compression forces with genu varum?
medial compartment compression
Which area of the knee receives greater compression forces with genu valgum?
lateral compartment compression
What factors lead to genu valgum?
- previous injruy
- genetic predisposition
- high BMI
- laxity of ligaments
- abnormal alignment and muscle weakness at either end of lower extremity
What knee ligaments have increased stress during genu valgum? What happens to the patella?
- increased stress on MCL due to increased compression on lateral component
- increased stress on ACL
- excessive lateral tracking of the patella
What factors lead to genu varum?
thinning articular cartilage on medial side
What happens with genu varum?
- increased medial compartment loading
- greater loss of medial joint space
- greater knee adduction movement
- increased strain on LCL
- increased medial joint loading
What is genu recurvatum?
excessive hyperextension of the knee
Define the Q-angle. What happens if the Q-angle is increased?
- estimation of the line of pull of quadriceps
- angle formed by line connecting ASIS to middle of patella and line connecting tibial tuberosity to middle of patella
- increased Q-angle increases lateral force on the patella which makes patella prone for dislocations
What is the normal Q-angle range?
13-15 degrees
Describe the factors that naturally oppose the lateral pull of the Patella.
Local Factors
- patella alta - raised lateral facet of trochlear groove
- VMO
- medial patella retinacular fibers
Global factors
- excessive genu valgum
- compensated Trendelenburg sign
- everison of subtalar joint
- ER of knee
- IR of knee while walking
What are the functions of the meniscus?
- distribute weight bearing forces
- increase joint congruence
- shock absorption
What structures have connections to the medial meniscus?
MCl
ACL
PCL
semimembranosus
What structures have connections to the lateral meniscus?
ACL
PCL
popliteus
What is the primary function of the ACL?
primary restraint to anterior translation of tibia on femur
What is the primary function of the PCL?
Primary restraint to posterior translation of tibia on femur
What is the primary function of the MCL?
Primary restraint to valgus force and lateral tibial rotation
What is the primary function of the LCL
Primary restraint to varus stresses
What assists ACL in resisting anterior translation of the tibia on femur?
iliotibial tract
What are 3 factors associated with non-contact injuries?
- strong activation of quad over moderately flexed or nearly extended knee
- valgus collapse of knee
- excessive ER of knee
What are the osteokinematics of the knee?
- flexion/extension
- IR/ER
- Ab/Adduction
What are arthokinematics of flexion of the knee in OKC and CKC?
OKC - concave tibia on convex femur - posterior roll and glide
CKC - convex femur on concave tibia - posterior roll and anterior glide
What are arthrokinematics of extension of the knee in OKC and CKC?
OKC - concave tibia on convex femur - anterior roll and glide
CKC - convex femur on concave tibia - anterior roll and posterior glide
What are arthrokinematics of knee IR/ER?
not defined
What are arthrokinematics of knee Ab/Adduction?
not defined
Describe the screw home mechanism.
- 10 degrees of ER with terminal extension needed clear medial femur
- to unlock the knee, knee must IR to clear medial condyle
Describe the closed pack, open pack and capsular pattern of the knee.
closed pack - full extension
open packed - 25 degrees off flexion
capsular pattern - flexion > extension
What position of the knee puts the patella at greatest risk for dislocation and why?
full knee extension - patella has least congruency with joint
Describe the external torque demands of the quad with a leg extension vs a squat from 0-90 degrees.
OKC - greatest torque with leg extension is between 45-0 degrees of extension - external moment arm is longer as leg moves into 0 degrees of extension
CKC - greatest torque with squat is between 45-90 degrees of knee flexion - external moment arm is longer the more flexed the knee is/deeper the squat
Compare and contrast safe vs unsafe landing patterns
Unsafe
- larger knee EMA
- smaller hip EMA
- stiff landing
Safe
- small knee EMA
- Large hip EMA
- increased hamstring to quad contraction pattern
Describe the functions of the foot and ankle.
- foot able to sustain large weight-bearing stresses
- stable foot to provide appropriate BOS
- foot is a rigid lever for pushing off
- foot must be mobile enough to accommodate and adapt to uneven terrain and absorb shock when foot hits the ground
List the joints of the ankle/foot complex.
- proximal/distal tibiofibular joints
- talocrural joint
- talocalcaneal joint
- transverse tarsal joint (talonavicular and calcaneocuboid joint)
- tarsometatarsal
- metatarsophalangeal joints
- interphalengeal joints
What bones make up the hindfoot?
talus and calcaneus
What bones make up the midfoot?
- navicular
- cuboid
- 3 cuneiform bones
What bones make up the forefoot?
metatarsals and phalanges
What is the closed packed position of the proximal and distal tibiofibular joints?
weight bearing dorsiflexion
List the component OKC ankle motions associated with pronation. List the component ankle motions associated with supination.
Pronation - Pros do ABs Every Day
- Abduction
- Eversion
- Dorsiflexion
Supination - Sadly Injury ADDs Pain
- Inversion
- Adduction
- Plantarflexion
List the component CKC ankle motions associated with pronation. List the component ankle motions associated with supination.
Pronation
- Eversion
- Adduction
- Plantarflexion
Supination
- Inversion
- Abduction
- Dorsiflexion
Describe the functions of the medial collateral (deltoid) ligament and the lateral collateral ligament.
MCL (deltoid) - limit eversion/pronation
LCL - limit inversion/supination
What is the main motion at the Talocrural joint?
plantar and dorsiflexion
What are arthrokinematics of dorsi and plantarflexion?
convex on concave
Dorsiflexion - anterior roll, posterior slide
Plantarflexion - posterior roll, anterior slide
Describe the closed pack, open pack and capsular pattern of the Talocrural joint.
closed pack - weight-bearing dorsiflexion
open packed - 10 degrees of plantarflexion w/ neutral inversion/eversion
capsular pattern - plantarflexion > dorsiflexion
What are the main motions at the subtalar joint?
inversion/eversion and abduction/adduction
Describe what occurs with supination and pronation in non-weight bearing position and weight bearing posting during CKC.
weight bearing
- supination (medial longitudinal arch is higher) - calcaneus inverts, talus abducts and dorsiflexes
- Pronation (medial longitudinal arch is lower) - calcaneus everts, talus adducts and plantarflexes
Non-weight bearing
- supination - calcaneus inverts, adducts, and plantarflexes
- pronation - calcaneus everts, abducts, and dorsiflexes
Describe the closed pack and open pack of the subtalar joint.
closed pack - full inversion
open pack - mid inversion/eversion and mid plantar/dorsiflexion
What joints make up the transverse tarsal joint? What function does it serve?
talonavicular and calcaneocuboid
- link between hindfoot and forefoot
- add supination/pronation ROM of subtalar joint in OKC
- compensate at forefoot for hindfoot position in CKC
Describe the closed pack, open pack and capsular pattern of the transverse tarsal joint.
closed pack - supination
open pack - mid range of supination/pronation
capsular pattern - limitations in dorsiflexion, plantarflexion, adduction and IR
What is the function of the tarsometatarsal joints?
regulate position of the forefoot in relation to the weight-bearing surface
Describe what happens with the supination twist.
- Substantial weight-bearing pronation of the hindfoot results in supination of the transverse tarsal joint to counter rotate the forefoot
- If this supination is not sufficient the entire forefoot will also supinate
Describe what happens with the pronation twist.
- Full subtalar supination results in supination at the transverse tarsal joint as well
- At this point, the forefoot must pronate in order to maintain contact with the ground
Describe the 2 deformities outlined that may occur at the 1st MTP joint.
Hallux limitus (turf toe)
- gradual and significant limitation of motion, articular degeneration and pain
- unable to flex through big toe
Hallux valgus (bunion)
- Progressive lateral deviation of great toe
- can lead to lateral dislocation
What is the one of the main functions of the plantar fascia?
- support medial longitudinal arch in weight bearing
Describe the windlass effect.
- plantarflexion lifts calcaneus
- body weight transferred over metatarsal heads
- causes extension of metatarsophalangeal joints
- stretches (winds up) plantar fascia
- strengthens midfoot
Define pes planus. What effect does this foot posture have on the the overall function of the foot?
- abnormally dropped medial longitudinal arch (flat foot)
- compromises ability to support and dissipate loads
- tibialis posterior is having to work harder to maintain the arch which can lead to injury
What is the navicular drop test? What does it assess?
- Measurement of distance between navicular tuberosity and ground in subtalar joint neutral and with relaxed foot posture
- assess if medial longitudinal arch is at a sufficient height, 7 mm is normal
What role does the posterior tibialis muscle play in stance phase of ambulation?
- decelerates (eccentrically) pronating rearfoot in loading response
What is pes cavus?
increased medial longitudinal arch
