Ankle & Foot Complex Flashcards
What makes up the forefoot?
Metatarsals & phalanges
What is the function of the forefoot?
-Adapts to terrain
-Influenced by hindfoot
what makes up the mid foot?
Navicular, Cuboid & 3 Cuneiform
what is the function of the mid foot?
-Transmits hind foot motion to forefoot
-Promotes stability of foot
-Heavily influenced by hindfoot
what is the hind foot made up of?
Talus & calcaneus
what is the function of the hindfoot?
Converts LE transverse plane into sagittal, Frontal & horizontal plane
What are the 3 motions included in pronation?
DF, Eversion, & Abduction
what are the 3 motions included in supination?
PF, Inversion & Adduction
What is the M-L asymmetry in the frontal plane of the Proximal Talocrural joint?
Lateral malleolus is more distal than the medial malleolus
what is the M-L asymmetry in the transverse plane of the proximal Talocrural joint?
Lateral malleolus is more posterior than the medial malleolus
What is the A-P asymmetry in the frontal plane of the proximal Talocrural joint?
Lateral malleolus is more distal than the medial malleolus
Why is the closed pack position of the Distal Talocrural joint DF?
Anterior portion of the talus is wider than posterior
why is there more lateral movement of the distal talocrual joint?
cone directed w/ apex is more medial so the lateral taller surface is larger than the medial
what is the AFTL a check rein for?
PF & Inversion
what is the calcaneofibular a check rein for?
inversion
what is the posterior lateral malleolar a check rein for?
DF
what is the posterior talotibial a check rein for?
DF
what is the medial deltoid ligament a check rein for?
Eversion
what are the talocrural OKC DF arthrokinematics?
Convex talus moving on concave mortise
Anterior taller roll & posterior slide
what are the talocrural CKC DF arthrokinematics?
concave mortise moving on convex talus
Anterior mortise roll & slide
in Talocrural CKC what results from anterior malleolar movement being larger lateral than medial?
Adduction (Medial rotation) of mortise on talus
What results from the radius curvature of talus being larger on the lateral side than medial?
Fibular rotation
DF: medial
PF: Lateral
what are muscular check rein for DF?
Gastrocnemius & Soleus
what are the muscular check rein for PF?
Tibialis Anterior, Extensor Hallucis Longus & Extensor Digitorum Longus
what are the muscular check rein for eversion?
TIbialis Posterior, Flexor digitorum Longus, Flexor Hallucis Longus
what are the muscular check rein for inversion?
P.L & P.B
what does the Interosseous talcalcaneal limit?
Eversion
What does the lateral talocalcanelal limit?
inversion
what dose the ligament crevices limit?
inversion
what happens when the subtalar supinate OKC?
Calcañal :
- Inversion
- Adduction (medial rotation)
- PF
what happens when pronate pronate in OKC?
Calcaneal:
- Eversion
- Abduction (lateral rotation)
- DF
in CKC why doesn’t the calcaneus go from ABD/ADB or PF/DF on talus?
the body weight prevents
in subtalar CKC what happens during supination?
Calcaneal inversion
Talar Abduction (lateral rotation)
Df
in subtalar CKC what happens during pronation?
Calcaneal eversion
Talar Adduction
PF
how much talar abduction/adduction in the subtalar joint is required for gait?
10 degrees
how much supination & pronation is required for gait?
4-6 degrees
what is the closed pack position for the subtalar joint?
supination
what is the open pack position for the subtalar joint?
pronation
what is the magnitude of motion in the sagittal plane for DF of the Talocrural joint?
20-35
what is the magnitude of motion in the sagittal plane for PF of the Talocrural joint?
30-50
what is the magnitude of motion in the transverse plane of adduction of the Talocrurak joint is?
7
what is the magnitude of motion in the transverse plane for abduction of the Talocrual joint?
10
what is the magnitude of motion in the frontal plane for inv/ev of the Talocrual joint?
5
how far away from being a perfect M-L axis is the talocrural joint?
8-10°
how far forward is the axis into the transverse plane for the talocrural joint?
20-30°
what degree of inclination allows for good IN/EV & ABD/ADD in the subtalar joint?
42°
how far up into the sagittal plane does the subtalar joint go?
42
how far in does the subtalar joint go?
16
how far up into the sagittal plane does the talocalcaneonavicular joint go?
40
how far in does the talocalcaneonavicular joint go?
30
how far does the Transverse Tarsal (long) joint go up into sagittal plane?
15
how far in does the axis of transverse tarsal (long) go in?
9
how far up does the transverse tarsal (oblique) go up?
52
how far does the transverse tarsal (oblique) go in?
57
why is stability needed for the ankle-foot?
- Provide stable BOS
- Act as rigid lever
why is mobility needed for the ankle-foot?
- Dampen LE rotation
- Adapt to varied surface
- Flexible to absorb shock
what is the normal value of DF (sagittal plane) of Talocrural Joint?
20-35°
what is the normal value of PF (sag plane) of Talocrural joint?
30 - 50°
what is the normal value of adduction (transverse plane) of Talocrural joint?
7°
what is the normal value of abduction (transverse plane) of Talocrural joint?
10°
what is the normal value of inversion (frontal plane) of talocrural joint?
5°
what is the normal value of eversion (frontal plane) of talocrural joint?
5°
what are the CKC arthrokinematics of the subtalar joint?
Talar motion is a complex screw motion
what is the closed pack position for the subtalar joint & why?
Supination b/c the axis cross
what is the open pack position for the subtalar joint?
Pronation b/c the axis are parallel
how do you calculate RF Neutral position?
inversion + eversion = total STJ Motion
Total STJ/3
RF Valgus - (total STJ/3)= Amt varus
will severe restriction of talar abduction PROM lead to reduction in supination or pronation ROM in OKC?
Calcaneous is free to move on talus so talar abduction limitation in an open chain will not limit supination or pronation
will severe restriction of talar abduction PROM lead to reduction in supination or pronation in CKC?
WB restricts calcaneal ABD/ADD & PF/DF so talus has to move to supply component motion b/c abd & DF of talus is required for CKC supination
what makes up the talocalcaneonavicular joint?
Talonavicular & subtalar joints
what Is one significant Biomechanical aspect of TCN joint?
WB locks navicular movement, ligaments bind calcareous to navicular so CKC TCN joint motion is the talus moving on relatively fixed C-N unit
how is TCN the key to foot function?
Foot distal to TCN form a single elastic unit that will move in response to & in compensation for subtalar motion
what joints make up the transverse tarsal joint?
Talonavicular & Calcaneocuboid
what two joint complexes is the talonavicular apart of?
Transverse tarsal & talocalcaneonavicular joint
what is the function of the short & long plantar ligaments?
maintain longitudinal arch of foot
what is the function of the lateral band of the bifurcate?
check PF
what is the function of the dorsal calcaneocuboid?
check inversion & resist PF
which two joints are linked mechanically?
STJ & TTJ
CKC STJ (talar) ABD/ADD & DF/PF cause motion where?
talonavicular joint
CKC STJ (calcaneal) Iv/EV cause motion where?
calcaneocuboid joint
what are the two function of the transverse tarsal joint?
1) Add to supination/pronation range of STJ
2) Compensate forefoot for hindfoot position
what is the function of the tarsometatarsal joint mechanics?
attempts to maintain forefoot contact w/ supporting surfaces when TT motion is not good enough
T or F: The Tarsometatarsal Joints have independent oblique axes for each ray
True
1st & 2nd ray axis inversion is coupled with?
DF
1st & 2nd ray axis eversion is couple with?
PF
4th & 5th ray axis eversion is coupled with?
DF
4th & 5th ray axis inversion is coupled with?
PF
what occurs at the TMT joint in supination twist?
(1st & 2nd ray) DF & IV
(4th & 5th ray) PF & IV
what occurs at the TMT joint in pronation twist?
(1st & 2nd ray) PF & EV
(4th & 5th) DF & EV
when does the pronation & supination twist occur?
when TTJ function is not able to counter rotate or is insufficient to fully compensate for hindfoot position
Describe the Windlass Mechanism?
- Plantar pads move distally during toe DF
- Plantar fascia pulls forward & around MT head
- Results in supination & reduces distance b/w MT head & Calcaneus
- So arch height increases
Overtime what would supination do to plantar aponeurosis?
adaptively shorten
Overtime what would pronation do to plantar aponeurosis?
adaptively lengthen
what percentage of body weight is directed to talus?
50%
what percentage of BW is directed to forefoot?
25%
what percentage of BW is directed to rear foot?
25%
in terms of stabilization to the 1st ray what does the tibialis posterior do?
will PF & ADD 1st ray, important for stabilization at push off
what are 3 Biomechanical consequences of tip posterior compensatory pronation?
- Adduction & PF of talus
- Navicular & medial cuneiform depression
- Tension overloads tibs post
In terms of stabilization of the 1st ray what does fibularis longus do?
AB & PF 1st ray, important for stabilization at push off
Heavily influenced by position of cuboid pulley
describe cuboid pulley?
Displaces fibularis tendon inferiorly to improve PF moment (MA & torque output)
what would occur with alteration of cuboid pulley?
Reduces mechanical advantage to PF & ABD 1st ray
what are 3 consequences of fib longus compensatory pronation?
- Alteration of cuboid pulley
- Reduced advantage to PF & ABD 1st ray
- DF 1st ray & 2nd MT head overload
what will occur if rear foot varus is uncompensated?
- Medial plantar condyle will be off ground
- Excessive WB of lateral foot
- 5th metatarsal head callus
- Failure of STJ to pronate reduces the shock absorbing qualities of foot
what will occur if rear foot varus is compensated?
Calcaneal eversion from STH pronation
what will occur if forefoot varus is uncompensated?
- Medial forefoot will be off ground
- Excessive WB 5th ray
- 5th metatarsal head callus
what will occur with compensated forefoot varus?
Medial MT depression from STJ pronation
what will occur if a rigid forefoot valgus is uncompensated?
- Lateral forefoot will be off ground
- Excessive WB 1st ray
- 1st metatarsal head callus