Biomechanical Foot Exam of Foot & Ankle Flashcards
Criteria for Normal Function of the Foot
- Tibia vertical
- Calcaneus vertical-5o Varus
- Forefoot is perpendicular to bisection of calcaneus
- 10o true ankle DF @ all times**
- 1st Ray in plane of 2-4th rays
- does’t hang lower, or go higher
- **70-75o 1st MTP EXT****
Biomech. Exam of Foot & Ankle
Observe:
- Observation of foot & LE in WB and NWB
- check Gait
- check ROM
- check Biomech. Align.
Biomech. Exam of Foot & Ankle
Observation of foot in Standing & Sitting
What are we looking at?
- Arch ht.
- Heel pos.
- Orientation of forefoot
- Ex. “Too many toes sign”
-
Callus formation
- bring in shoes!!!
- where is most WB distribution?
- Shoe wear
-
ONLY observe shoes w/ @ least 100mi walk/run
- New shoes will tell you nothing!!!
-
ONLY observe shoes w/ @ least 100mi walk/run
Biomech. Exam of Foot & Ankle
Range of Motion:
where?
- Ankle jt (Talocrural)
- Subtalar jt
- inv/Ev
- Mid-Tarsal jt
- 1st ray mvmt
- 1st MTP
- enough for EXT?
- 70-75o req’d***
Relationship b/w Subtalar Jt & Mid-Tarsal Jt Motion
Sub-talar Pronation
P.DEAB
(DF, Ev, ABD)
- Sub-Talar Pronation (floppy foot)
- INC Mid-tarsal motion
- Forefoot MORE mobile
- accomodates surfs.
Relationship b/w Subtalar Jt & Mid-Tarsal Jt Motion
Sub-Talar Supination
IPAD
(Inv, PF, ADD)
- Sub-Talar Supination (Rigid foot)
- DEC Mid-tarsal motion
- Forefoot more rigid
- transmits forces—-when we NEED rigid foot
- NEED rigid foot for push-off
Significance of Sub-talar jt & Mid-tarsal jt motion Relationship in Gait
Loading to Midstance
- LR–>MSt
-
Sub-Talar Pronation=forefoot more mobile
- #FloppyFoot
- improves shock absorb.
-
Foot MORE adaptable to changing terrain
- ==> more stable BOS
-
Sub-Talar Pronation=forefoot more mobile
Sig. of Sub-talar & Mid-tarsal Motion Relationship in Gait
Midstance to Toe-off
- MSt–>Toe-off
-
Sub-talar Supination= Forefoot more Rigid
- #RigidFoot
- Provides rigid lever for efficient push-off
-
Sub-talar Supination= Forefoot more Rigid
Consequences of Altered Sub-Talar & Mid-tarsal Motion Relationship
Excessive Pronation
Too Floppy
- Excessive Pronation
-
Foot NOT RIGID ENOUGH during Toe-off
- too floppy
- ineff. push-off
-
Foot NOT RIGID ENOUGH during Toe-off
Consequences of Altered Sub-talar & Mid-tarsal Motion Relationship
Excessive Supination
Too Rigid
- Excessive Supination
- Foot remains TOO RIGID t/o Gait
-
LESS shock absorb
- now more force to BONE instead of soft tissues
-
LESS adaptability to changing terrain
- LESS stable
*NOTE: we want force taken up by mm’s, THEN ligs, tendons, bones***
Pes Cavus aka
High Arch
Pes Cavus
High Arch
like a “Cave”
- Forefoot PF’d
- Rearfoot Supinated during WB
- Rigid Foot
- Pt. Over-Supinates
- Poor shock absorb.
- Limtd DF
- Ankle must DF to get tibia perp. to ground.
- Pt will appear to have limtd DF during stance bc most of range already used up
- Prone to disorders assoc’d w/ over-supination
Pes Planus aka
Flattened Arch
Flat Foot
Pes Planus
Flattened Arch
- Flattened arch and valgus rearfoot during WB
-
Rigid Pes Planus
* result of bony structural abnorm. of arch- Flat all the time*
-
Rigid Pes Planus
-
Flexible Pes Planus
* result of weak supinator mm’s (Tib. Post.)- Flattens out IN WB
- Mm weakness
-
Flexible Pes Planus
- Pt. appears to Over-Pronate during gait.
- Prone to other disorders of foot related to over-pronation
Abnormal Pronation
What is it?
- Pronation that is excessive in range OR that which occurs when foot SHOULD BE supinating:
- @heel strike, push-off (when we need a rigid (supinated) foot!
Abnormal Pronation
Caused by Abnorms in all 3 planes:
-
Frontal Plane
- tibial varus
- subtalar varus
- forefoot varus
-
Transverse Plane
- Hip anteversion
- Internal femoral torsion
- Internal tibial torsion
-
Sagittal Plane
- Equinas
- Limtd knee or hip EXT.
- *Leg length (longer side)
Effects of Abnormal Pronation–Floppy Foot
Foot Injuries:
- callus/pain under 2-4 MT heads AND plantar medial 1st MTPJ AND medial heel from pinch
- Hallux Rigidus/valgus
- Morton’s Neuroma
- Plantar Fasciitis
- Metatarsal Stress Fx’s
- 2nd/3rd MT’s
Effects of Abnormal Pronation–Floppy Foot
Leg Injuries:
- Achilles tendinitis —-bc alwasy stretched
- Tib. Post tendinitis
- Tib/Fib Stress Fx
- Ant/Med knee pain
- bc IR tibia
Modified Low-Dye Taping
For Over/Abnormal Pronated Foot
see pics
Navicular Sling Taping
For Over/Abnormal Pronated Foot
- anchor tape just dist. and slight ant. to Lat. Malleolus
- Pass tape under plantar aspect of foot
- Tape should cover navicular on Med. aspect of foot
- Provide support to med. arch by lifting UP on tape to elevate navicular
- Maint. tension on tape and secure in spiral fashion around lower leg
Abnormal Supination
What is it?
- Supination that is excessive in range OR that which occurs when foot should be pronating
- i.e. Midstance****
Abnormal Supination
Components:
- Rigid everted forefoot
- implies inad. INV about LMTJ axis
- Forefoot valgus
- PF’d first ray
- Equinas deformity in which heel cannot reach ground
- *Leg length (shorter side)
Pronated Foot makes leg ____________
Supinated Foot makes leg _________
Pronated foot makes the leg Longer
Supinated foot makes the leg Shorter
Effects of Abnormal Supination
Foot Injuries:
- Callus/pain under 1st-5th MT heads
-
Sesamoiditis and/or Stress Fx’s
- 5th MT
- Hammer toes
- Haglund’s deformity
- Pump bump
-
Chronic lat. ankle sprain
- bc alwasy in INV
Effects of Abnormal Supination
Leg Injuries:
- Achilles tendinitis
-
Peroneal tendinitis
- bc always working ecc. controlling INV.
- Lateral Knee and Hip pain
Rigid PF’d 1st Ray
usually assoc’d w/:
- Usually assoc’d w/ uncompensated rearfoot varus
Rigid Plantarflexed 1st Ray
What happens to get this?
- Limtd S-T motion maintains calcaneus in INV’d pos. t/o stance phase
- Develop lateral instability of ankle & callus under 1st & 5th MT heads
Rigid PF’d 1st Ray
Requires what?
- Req’s accomodative orthotic w/ cut-out for 1st ray OR bar from 2nd-5th MT
- builds ground UP under 2-4th MT heads
- also now 5th MT ends up WB more than it should ***
Equinas Deformity
- Less than 100 True ankle jt DF
- Creates LARGE deforming force @ S-T & M-T jts
- Need for abnorm. pronation persists thru heel-off
- Req’s intervention to restore DF and/or heel lift
Subtalar Neutral
What is the pos. of the foot?
- Foot pos. where subtalar, talonavicular, calcaneocuboid are congruous
Subtalar Neutral
How is the Clinically done?
- Foot is placed in neutral by centering Navicular ON Talus
- pt in relaxed standing
- kneel @ side of pt—use tips of thumb and index to palpate med. and lat. aspects of head of talus
- pt rotates trunk to one side, then other, in order to medially rotate tibia (producing pronation) OR laterally rotate tibia (producing supination)
- Have them “stop” when talar head does NOT bulge to either side===> Subtalar Neutral
- NOTE: MOST pts pronated in relaxed standing—–to get STJ neutral—-pt must supinate foot to achive “neutral” pos. that is neither pronated nor supinated
*AFTER foot placed in neutral position===> possible to determine relative Varus/Valgus of Rearfoot and Forefoot
