kinesiology lower limb

what type of activities does the HAT segments support?

dynamic and static

what does HAT stand for?

head

arms

trunk

what joint is the baseline for the lower extremity?

hip

what joint contributes to force transmission

knee

what joint is for shock absoption

knee

what joint shortens swing limb for gait

knee

what joint accomodates for different activities and surfaces

ankle/foot

what joint is the rigid lever vs mobile adaptor for gait

ankle/foot

what joint contributes to proximal stability

hip

what joint supports weight bearing function

hip

what joint manages weight bearing forces

ankle/foot

how are the feet aligned relative to the hip?

directly under hip for posture and dynamic function

what joint is anterior to the line of gravity in typical posture?

hip

How is the acetabulum (femoral head coverage) different between the anterior side vs posterior side of joint?

less stability and congruency = anterior side

more stability and conrguency= posterior

what angles occur in the transverse plane?

acetabular anteversion angle

femoral torsion

what angles are in the frontal plane?

center-edge angle

angle of inclination

what 2 angles explain coverage of femoral head

Acetabular anteversion angle

Center-edge angle

An increased angle means MORE / LESS coverage of the femoral head? acetabular anteversion angle

less coverage

less stable

less congruency

How much does the acetabulum projects laterally and superiorly relative to the femoral head in the frontal plane?

A decreased angle to only 15° can reduce the contact area by 35%

less contact

less surface area

what is the atypical angle and degrees for coxa valga?

>125

what is the atypical angle for coxa vara?

<125 around 90 degrees

what are the types of angle of inclination?

coxa valga

coxa vara

what does coxa valga do to the weight vector ?

shortens weight vector force

lowers bending force

what does coxa vara do compared to the femoral head?

bending force is higher

increases stability

what is the positive response to coxa vara ?

Increased moment arm for hip abductor

increases stability

what is the positive response for coxa valga ?

Decreased shear force

decrease bending force at femoral neck

Increased length of hip abductor muscle

verticle force = compressive force

what is the negative response for coxa valga ?

Decreased arm for hip abductors

Less joint stability

what is the negative response for coxa vara ?

Increased shear force and bending

high moment of weakness

decreased hip abductor function

what is typical femoral torsion and what plane is it in ?

Transverse plane

between the femoral head and neck

10-20 degrees

how much does the typical femoral torsion decrease a yr?

1.5 until mature

what are the 2 terms for atypical femoral torsion?

increased anteversion =more than 15-20

retroversion= less than 15-20

What is the effect of an increased acetabular anteversion angle on the coverage

of the femoral head?

less coverage on the head

higher risk of dislocation

What is an outcome of an increased femoral anteversion angle on typical standing alignment?

external rotation of hip and knee

in toeing

Which type of angle of inclination can create more shear force at the femoral neck?

coxa vara

what joint does the femoral angle of inclination make up

hip joint

why is the tibiofemoral joint able to laterally rotate during swing phase of gait

10 degrees lateral

lateral femoral condyle is shorter

acl pulls laterally

lateral quad pulls laterally

what is the degrees of increased genu valgus

<165

what is the decreased genu varum angle

>180

what angle is tibia torsion measured by

foot-thigh angle

15 degrees external

what are the 3 major joints of the ankle and foot?

talocural

subtalor

transverse tarsal

what are the 3 major joints of the ankle and foot?

talocural

subtalor

transverse tarsal

what is the talocural joint role?

80% of compressive forces

source of stability

what are the 3 articularting surfces of the subtalor joint

posterior

anterior

medial

what is the keystone for the transverse arch

medial cuneiform

what is the keystone for the longitudinal arch

talus

what joints make up the transverse tarsal joint

talonavicular

calcaneocuboid

what motions make up supination

hindfoot eversion (varus)

forefoot adduction

plantarflexion

rigid

what motions make up pronation

hindfoot inversion (valgus )

forefoot abduction

dorsiflexion

flexible

what does the subtalor joint in relation to mobility and stability

limits mobility but improves stability

what does the screw home mechanism do in knee extension?

maximizes contact and stabiity

what does the screw home mechanism do in knee extension?

maximizes contact and stabiity

what joint has the greatest motion in dorsiflexion/flexion and which ones specifically

tarsometatarsal 1,4,5