SLIDE 1
Section 30: Knee Biomechanics Movement and Forces
30-1
30-2 From: Iatridis
Section 30: Knee Biomechanics Movement and Forces 30-1 From: - - PowerPoint PPT Presentation
Section 30: Knee Biomechanics Movement and Forces 30-1 From: - - PowerPoint PPT Presentation
Section 30: Knee Biomechanics Movement and Forces 30-1 From: Iatridis 30-2 From: Iatridis 30-3 Joint Stability Dependent Upon Joint Stability Dependent Upon Bony congruence Bony congruence Ligamentous structures Ligaments
SLIDE 2
SLIDE 3
30-3 From: Iatridis
SLIDE 4
Joint Stability Dependent Upon Joint Stability Dependent Upon…
- Bony congruence
Bony congruence
- Ligamentous structures
– Ligaments Ligaments – Joint capsule – Meniscus Meniscus
- Muscles
– Flexibility Flexibility – Strength – Co-contraction
30-4 From: Peeler
Co contraction
SLIDE 5
Ligaments Ligaments
- Medial (tibial) collateral
( )
– 50% of max load in ext. – As knee flexes, loads shared by capsule, Ant and Post Cruciates
- Lateral (fibular) collateral
Lateral (fibular) collateral
– 55% of max load in ext. – Loads increase as knee flexes because post. structures become lax lax
- Anterior cruciate ligament
– 75% max load in full ext. 90% max load in full flex – 90% max load in full flex.
- Posterior cruciate ligament
– Up to 100% load at 30° and 90° of knee flex.
30-5 From: Peeler
SLIDE 6
Special Tests Special Tests
30-6 From: Scifers
SLIDE 7
Right Knee Right Knee
Medial head of gastrocnemius muscle Tendon of semimembranosus semimembranosus muscle
30-7 From: Garner
Anterior View Anterior View Posterior View Posterior View
SLIDE 8
30-8 From: Garner
SLIDE 9
30-9 From: Crosby
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ACL Tears ACL Tears
M t h i
- Most common mechanisms
– Contact:
- CKC with foot ER w/ valgus stress
CKC with foot ER w/ valgus stress
- Hyperextension
- direct hit on the posterior tibia
– Non-Contact: – Non-Contact:
- Most common
- Due to sudden deceleration
- Sudden landing cutting or pivoting
- Sudden landing, cutting, or pivoting
- Patient will c/o “buckling” or “giving
away”, typically will hear and/or
30-10 From: Scifers
feel a “pop”
SLIDE 11
Mechanism of Injury Mechanism of Injury
- Trauma
Trauma
– Compression – Rotational Force – Valgus Force – Valgus Force – Usually Combination of Forces
- Degenerative Changes
G t th 30 ld – Greater than 30 years old – No PMHX required – Often due to MOI that “seemed harmless” at time harmless at time
Noyes 2002 states 60% of meniscal injuries associated with ACL injury
30-11 From: Scifers
Noyes, 2002 states 60% of meniscal injuries associated with ACL injury
SLIDE 12
30-12 From: Materials and Textiles