Final Exam Red Stars Flashcards
Tibiofemoral Joint’s Arthrology
Convex Femoral Condyles
Concave Tibial Condyles
Relies on soft tissue to stabilize in frontal & transverse plane movements
Iliofemoral Ligament limits:
Excessive extension and excessive external rotation
(Some people “stand on it”)
Pubofemoral Ligament limits:
Hip Abduction & Hip Extension
Ischiofemoral Ligament limits:
Hip Internal Rotation (esp. 10-20 degrees of abduction) and Hip Flexion
Ligaments of Hip in Close-packed position:
Full extension, with slight internal rotation & abduction is when ligaments are tightest
Ligaments of Hip in Open-packed position:
30 degrees flexion, 30 degrees abduction and slight internal rotation
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
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
Hip Arthroplasty precautions with posterior approach
No Flexion > 90 degrees
No ADD past neutral
No Internal Rotation
Hip Arthroplasty precautions with anterior approach
No Extension
No ABD past neutral
No External Rotation
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
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
Excessive Anteversion presents as ______ clinically.
Toe-in gait
Retroversion presents as ______ clinically.
Toe-out gait
Role of Meniscus
-Reduce compressive stress (triples joint contact area)
-Stability
-Lubrication (reduce friction)
To ‘unlock’ the knee, popliteus must either _______ or ________ get knee internally rotated.
Externally rotate Femur or Internally rotate Tibia
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
Remember that Patella moves if _____ moves
Tibia
MCL limits
Valgus/abduction
LCL limits
Varus/adduction
Primary Function of MCL/LCL
Limit excessive knee motion in frontal plane
ACL
restricts anterior shear force (85%)
more taut in extension
PCL
restricts posterior shear force (95%)
more taut in flexion
Knee extensors (quads)
Rectus femoris (20% of force)
Vasti (80% of force)
Max torque ~ 80 - 45 deg of flexion
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
