Foot and Ankle Biomechanics

movements that make up pronation

DF, ABD, eversion

movements that make up supination

PF, ADD, inversion

arthrokinematics of DF for proximal and distal tibiofibular joints

proximal and slightly posterior

arthrokinematics of PF for proximal and distal tibiofibular joints

distally and slightly anterior

arthrokinematics of inversion for proximal and distal tibiofibular joints

distally and slightly posterior

arthrokinematics of eversion for proximal and distal tibiofibular joints

proximally and slightly anterior

OKC DF ROM

15-20 degrees

OKC PF ROM

45-55 degrees

arthrokinematics of OKC DF

anterior roll, posterior slide

mobilization of OKC DF

posterior mob on talus

arthrokinematics of OKC PF

posterior roll, anterior slide

mobilization for OKC PF

anterior talar

why is there more ROM with CKC DF?

weight bearing wides the ankle mortis increasing the ROM the ankle to go through

CKC DF ROM

40-50 degrees

arthrokinematics of CKC DF

anterior roll and slide

arthrokinematics of CKC PF

posterior roll and slide

what are the arthrokinematics of the subtalar joint name for?

posterior facet

what bones make up the subtalar joint?

talus and calcaneus

subtalar inversion ROM

12-25 degress

subtalar eversion ROM

5-12 degrees

arthrokinematics of subtalar inversion

medial roll, lateral slide

is the subtalar joint convex on concave, or concave on convex?

convex on concave

mobilization to improve subtalar inversion

lateral mob on the calcaneus

mobilization to improve subtalar eversion

medial mob on the calcaneus

arthrokinematics of subtalar eversion

lateral roll, medial slide

is the talonavicular joint convex on concave, or concave on convex?

• convex on concave

• ball and socket joint

why are the arthrokinematics of the talonavicular joint described as a spin?

this joint has the most pure pronation and supination (equal motion in all three planes)

arthrokinematics of supination at the talonavicular joint

spin upward

arthrokinematics of pronation at the talonavicular joint

spin downward

what does the spring ligament do?

• helps create the medial longitudinal arch

• supports the talar head in wt bearing

what structures does spring ligament run between?

from the sesentaculum tali to the navicular

what is the job of the calcaneocuboid joint?

stay stable

arthrokinematics of supination at the calcaneocuboid joint

cuboid moves plantarly and medially to get under the foot

arthrokinematics of pronation at the calcaneocuboid joint

cuboid moves dorsally and laterally to get out of the way as the joint on the medial side moves downwardly

arthrokinematics for flexion of 1st MTP joint

plantar roll and slide

1st MTP flexion ROM

30-45 degrees

1st MTP extension ROM

70-80 degrees

1st MTP abduction ROM

no norms

1st MTP adduction ROM

return to neutral

arthrokinematics for extension of 1st MTP joint

dorsal roll and slide

arthrokinematics for abduction of 1st MTP joint

medial roll and slide

arthrokinematics for extension of 1st MTP joint

lateral roll and slide

mobilization to improve 1st MTP flexion

plantar glide

mobilization to improve 1st MTP extension

dorsal glide

mobilization to improve 1st MTP ABD

medial glide

mobilization to improve 1st MTP ADD

lateral glide

what is the Windlass Mechanism?

• mechanism in which the foot goes from a pronated position to a supinated position

• wt bearing causes loss of height to medial longitudinal arch causing increased tension to build in plantar fascia

• when you go to MTP extension, it causes a shortening of plantar fascia and other intrinsic structures causing it to go into a more supinated position

1st PIP flexion ROM

30-90 degrees

PIP flexion ROM

35 degrees

DIP flexion ROM

50-60 degrees

PIP extension ROM

0 degrees

DIP extension ROM

0 degrees

arthrokinematics of PIP/DIP flexion

plantar roll and slide

arthrokinematics of PIP/DIP extension

dorsal roll and slide

mobilization to improve PIP/DIP flexion

plantarly

mobilization to improve PIP/DIP extension

dorsally