Final Exam Red Stars Flashcards by Haleigh Scott

Tibiofemoral Joint’s Arthrology

Convex Femoral Condyles
Concave Tibial Condyles
Relies on soft tissue to stabilize in frontal & transverse plane movements

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Iliofemoral Ligament limits:

Excessive extension and excessive external rotation
(Some people “stand on it”)

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Pubofemoral Ligament limits:

Hip Abduction & Hip Extension

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Ischiofemoral Ligament limits:

Hip Internal Rotation (esp. 10-20 degrees of abduction) and Hip Flexion

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Ligaments of Hip in Close-packed position:

Full extension, with slight internal rotation & abduction is when ligaments are tightest

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Ligaments of Hip in Open-packed position:

30 degrees flexion, 30 degrees abduction and slight internal rotation

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On which side of the body should you direct a patient to use a cane?

Opposite of the affected side.
-reduces amount of torque hip abductors have to create
-reduces HAF (hip abd force)
-reduces Hip JRF

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Which side of the body should you suggest a patient hold a bag if they present with Trendelenburg gait?

On the Ipsilateral side
-provides torque in same direction has hip abductors
-reduces HAF
-reduces Hip JRF

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Hip Arthroplasty precautions with posterior approach

No Flexion > 90 degrees
No ADD past neutral
No Internal Rotation

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Hip Arthroplasty precautions with anterior approach

No Extension
No ABD past neutral
No External Rotation

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Pros & Cons of Coxa Valga

Pros: decreased bending moment arm & decreased shear force & increased functional length of hip abd. muscles
Cons: Decreased moment arm & alignment favors joint dislocation

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Pros & Cons of Coxa Vara

(~90 degrees)
Pro: increased moment arm for rotation at hip & improved joint stability
Con: Increased bending moment arm which increases shear force on femoral neck & has decreased functional length

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Excessive Anteversion presents as ______ clinically.

Toe-in gait

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Retroversion presents as ______ clinically.

Toe-out gait

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Role of Meniscus

-Reduce compressive stress (triples joint contact area)
-Stability
-Lubrication (reduce friction)

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To ‘unlock’ the knee, popliteus must either _______ or ________ get knee internally rotated.

Externally rotate Femur or Internally rotate Tibia

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Screw-home mechanism

-Transverse Plane
-10 deg of ER of Tibia to lock knee in full extension
-Medial tibia travels further (causing ER) because medial condyle on femur is larger

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Remember that Patella moves if _____ moves

Tibia

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MCL limits

Valgus/abduction

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LCL limits

Varus/adduction

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Primary Function of MCL/LCL

Limit excessive knee motion in frontal plane

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ACL

restricts anterior shear force (85%)

more taut in extension

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PCL

restricts posterior shear force (95%)

more taut in flexion

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Knee extensors (quads)

Rectus femoris (20% of force)
Vasti (80% of force)

Max torque ~ 80 - 45 deg of flexion

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Knee flexors (hamstrings)

The semis IR knee, Biceps femoris ER knee Max torque is when its less flexed, but max leverage is when its more flexed

What muscle produces anterior tibial shear? (greatest in knee extension)

Quads

Patellar Compression Forces

QUADRICEPS FORCE!!! but also angle of knee flexion and weight bearing vs non-weight bearing

More knee flexion =

more PFJ stress

Non-weight bearing exercise creates less PFJ Stress than weight bearing in _____

45 deg to 90 deg flexion

Weight bearing exercise creates less PFJ compression force in

0 deg to 45 deg flexion

What muscle(s) produce posterior tibial shear? *good for ACL

Hamstrings

Dynamic Lower Extremity Valgus is a combination of what motions?

Hip ADDuction Hip IR Knee ABDuction Knee ER Ankle Pronation

What muscle group can become flexors/extensors if in high amounts of flexion/extension?

Hip Adductors

Hip Abductors

Glute med (60%) Glute min (20%) TFL (10%)

Forefoot components

Metatarsals Phalanges

Midfoot components

Navicular Cuboid Cuneiforms

Rearfoot components

Talus Calcaneus

Navicular Bone/Talonavicular Joint

Keystone of Arch

Dorsiflexion/Plantarflexion predominately occur at what joint

Talocrural

Inversion/Eversion

what calcaneus is doing relative to tibia

Pronation is a combination of

Eversion Abduction Dorsiflexion

Supination is a combination of

Inversion Adduction Plantarflexion

Tibiofibular Ligaments are where ______ sprains occur.

High ankle sprains

Tibiofibular Joints have _________ movement

virtually none

Talocrural Joint's Ligaments & Roles

Medial ones (Deltoid) resist eversion Lateral ones resist inversion

Talocrural provides ~80% of movement for ....

Plantarflexion (45-50%) Dorsiflexion (15-25%)

Subtalar joint has minimal _____ but can complete the other motions involved in pronating and supinating.

Minimal Dorsi/plantarflexion can evert + abduct (12 deg) can invert +adduct (22 deg)

Medial Longitudinal Arch

primary load bearing and shock absorbing structure in the foot

Medial Longitudinal Arch's Passive Support and Active Support

Passive = Talonavicular Joint = Keystone & Plantar Fascia Active = Intrinsic & Extrinsic (post tib) muscles

"Navicular Drop"

-Contributes to dynamic lower extremity valgus -Controlled by eccentric contraction of Post. Tib

Tibialis Anterior

Dorsiflexion and Inversion (concentric) Eccentrically controls plantarflexion and eversion

Fibularis Longus & Brevis

Primary action = eversion Secondary = plantarflexion Eccentrically works to prevent inversion ankle sprains

Gastroc (crosses knee) Soleus (doesn't cross knee)

Plantarflexion (concentrically) eccentrically controls dorsiflexion

Tibialis Posterior

Supination (inversion), Plantarflexion eccentrically controls pronation

When stretching plantarflexors, how do you target just gastroc and less soleus?

Stretch with knee extended (straight) If knee is flexed, soleus is more targeted

Pes Planus

Flat footed -excessive laxity or overstretched/torn/weak plantar fascia, spring ligaments, Post. tib. etc

Pes Planus may result in:

excessive pronation Rearfoot valgus/calcaneal eversion Forefoot varus/abduction Hallux valgus Wide Midfoot Excessive use of foot muscles Lengthening of plantar fascia lack of dorsiflexion

Pes Cavus

High Arch onset could be idiopathic, genetic, neurological

Pes Cavus may result in:

Rearfoot varus/inversion Claw Toes Forefoot valgus reduced contact area Angled metatarsals shortening of plantar fascia disuse of intrinsic foot muscles

Forefoot Varus

Forefoot is inverted relative to rearfoot and is not on the ground/NWB. To WB, calcaneal eversion has to occur to put forefoot on ground

Pes Planus Rigid vs Flexible

Rigid = bone or joint malformation; cannot dissipate forces/stress; more likely to fracture Flexible = drops even flatter when WB

Pes Cavus Rigid vs Flexible

Rigid= difficulty absorbing repeated impacts Flexible= able to cave some into a more normal arch, so it can absorb some load

Ankle Sprain

Compression side -> bony injury Tensile side -> soft tissue injury

Eversion Sprain

Posterior Tib

Inversion Sprain

Fibularis Longus/Brevis