The hip, knee and ankle joints Flashcards
Review of features of the hip, knee and ankle joints
What are the functions of the knee joint?
To support BW, transmit forces between femur and tibia, and provide movement for locomotion
What are the two joints of the knee?
The tibiofemoral joint and the patellofemoral joint
What type of joint is the tibiofemoral joint?
Synovial bicondylar
What distinguishes the condyles of the femur?
The lateral condyle’s articular surface profile is longer than the medial
What distinguishes the condyles of the tibia?
The lateral condyle of the tibia is smaller and more circular
How would you distinguish between the minisci?
The medial miniscus is a semicircle, whilst the lateral miniscus is 4/5 of a circle, and has a larger SA
What are the functions of the minisci?
To increase congruence between articulating surfaces, assist weight-bearing, shock absorb, and facilitate accessory movements
What are the names of the four major ligaments of the tibiofemoral joint?
Medial collateral ligament, lateral collateral ligament, anterior cruciate ligament, posterior cruciate ligament
What type of ligament is the MCL?
Extracapsular, is a broad flat band
What type of ligament is the LCL?
Extacapsular, is like a chord
What does the MCL prevent?
Valgus displacement
What does the LCL prevent?
Varus displacement
What type of ligament are the ACL and PCL?
Intracapsular
What does the ACL attach to?
Attaches from anterior intercondylar area to lateral femoral condyle
What does the PCL attach to?
Attach from posterior intercondylar area to medial femoral condyle
What does the ACL prevent?
Anterior tibial displacement
What does the PCL prevent?
Posterior tibial displacement
What type of joint is the patellofemoral joint?
Synovial, saddle
What is the function of the patella?
Acts as an anatomic pulley, reduces friction between the quad tendon and femoral condyles
How does the patella move with flexion and extension?
With flexion, moves distally. With extension, moves proximally.
What are bursae?
Fluid-filled sacs which reduce friction, typically between skin and bone/ tendon and bone
What is the major bursa of the knee joint?
The pre-patella bursa between the skin and knee-cap
When is the knee is its close-packed position?
When knee is in full extension
What is the close-packed position? (generally)
When tendons are tightest and there is maximum contact between bones
What are the functions of the ankle/foot?
Act as a shock absorber, generate propulsion, adapt to uneven surface, and act as a base of support
What are the arches the plantar vault are supported by?
The Medial, Lateral and Anterior transverse arches
What are contact points of the plantar vault?
Head MT 1 + 5, calcaneal tuberosity
What are the bones which the medial arch comprises of?
Calcaneus, talus, navicular, medial cuneiform, MT1
What are the bones which the lateral arch comprises of ?
Calcaneus, cuboid, MT5
What are the bones which the anterior transverse arch comprises of?
MT1-5
Which is the most flexible arch?
Medial
What is the flattest arch?
Anterior transverse
Which arch(es) has ground contact?
Lateral and anterior transverse
How are arches maintained? (general)
Wedge-shaped bones, a keystone at the top, and strong support
What is the gait cycle of walking?
Heel strike, stance, heel off, toe off
When are the arches raised most?
During heel strike
When is the vault flattened?
During stance
At what point is the foot a rigid lever between two force?
During heel off
What is the Windlass mechanism?
When plantar fascia tightens to reinforce medial arch during extension of hallux
At what point are the plantar tighteners not contracting?
During heel strike
What are the joints of the foot?
The subtalar and transverse tarsal
What is the subtalar joint?
Joint between talus and calcaneus, allowing movement of calcaneus
What is the transverse tarsal joint?
The calcaneocuboid and talonavicular joints, allowing movements of the forefoot
What movements are allowed at the foot/ankle?
Ab + adduction, dorsi- + plantarflexion, supination + pronation, inversion + eversion
What is inversion?
Adduction, plantarflexion, supination. Both fore and hind foot do the same movement
What is eversion?
Abduction, dorsiflexion, pronation. Both fore and hind foot do the same movement
When weight shifts laterally, which actions do the joints do?
Joints do opposite movements. Hindfoot abucts, supinates, and dorsiflex. Forefoot does opposite.
Name the ligaments of the hip
Iliofemoral, teres, pubofemoral, ischiofemoral
How would one identify the iliofemoral ligament?
Attaches from ilium to femur, crosses anteriorly
How would one identify the teres ligament?
Attaches from deep in acetabulum to depression in head of femur
How would one identify the pubofemoral ligament?
Attaches from pubis to femur, crossing anteriomedially + inferiorly
How would one identify the ischiofemoral ligament?
Attaches from ischium to trochanteric fossa of femur, crosses posteriorly, is triangular
Which ligament limits hip hyperextension?
Iliofemoral
Which ligament limits hip adduction?
Teres
Which ligament limits hip extension + abduction?
Pubofemoral
Which ligament limits internal rotation?
Ischiofemoral
