1. The Knee
ESAT 3600
Fundamentals of Athletic Training

2. Knee Complex 2 articulations Tibiofemoral (knee joint) Patellofemoral
Medial and lateral
Patellofemoral

3. Tibiofemoral Joint Articulation of the femur and tibia
Medial and lateral articulating surfaces
Femur has convex surfaces
Tibia has concave surfaces

4. Patellofemoral Joint Articulation of patella with femur
Patella serves as pulley mechanism for quadriceps muscles
PFPS
Chondromalacia

5. Bony Landmarks (Femur)
Lateral condyle
Lateral epicondyle
Medial condyle
Medial epicondyle
Adductor tubercle
Popliteal fossa
Intercondylar notch
Patellar facet

6. Bony Landmarks (Tibia)
Tibial tuberosity
Pes Anserines
Gerdy’s Tubercle

7. Pes Anserines
Point of insertion of sartorius, gracilis, and semitendinosus

8. Gerdy’s Tubercle
Small prominence on anterior aspect of lateral condyle of tibia
Insertion of IT band

9. Superior View of Tibia Intercondylar fossa Medial articular surface
Posterior
Anterior
Intercondylar eminence
Medial articular surface
Lateral articular surface

10. Patella Base Apex Lateral border Medial border
Lateral articulating surface
Medial articulating surface

11. Knee Movements
Flexion
Extension
Medial rotation
Lateral rotation

12. Arthrokinematics of Tibiofemoral Extension
Matter of perspective
Tibia moving on fixed femur
Femur moving on fixed tibia

13. Screw-Home Mechanism 3 factors Also a matter of perspective
Shape of medial condyle
Passive tension of ACL
Lateral pull of quadriceps
Also a matter of perspective
External rotation of tibia on femur
Internal rotation of femur on fixed tibia

14. Patellofemoral Joint Kinematics

15. Knee Stability Bony stability is extremely weak
Ligaments and cartilage provide most stability

16. Menisci and Attachment Sites
Medial
C-shaped
Lateral
Incomplete O

17. Ligament of Wrisberg
Lateral meniscus to posterior medial condyle

18. 4 Main Functions of Menisci
Maintain congruence between articular surfaces in all positions of the joint
Provide shock absorption in the joint
Maintain circulation of synovial fluid through articular cartilages
Help bring about normal movement between the articular surfaces

19. Meniscal Injury
Tearing attachments of the menisci to the tibial table and joint capsule
Crushing the menisci between the femoral and tibial condyles, produces circular (bucket handle) and radial tears

20. Joint Capsule
Common capsule for tibiofemoral and patellofemoral joints
Anterior part folds upward during extension
Posterior part folds downward during flexion

21. Knee Ligaments Lateral collateral Medial collateral
Attached superiorly to lateral epicondyle, inferiorly to head of fibula
Medial collateral
Attached superiorly to medial epicondyle, inferiorly to medial aspect of tibia below tibial condyle

22. Knee Ligaments Anterior cruciate
Distal attachment – posterior aspect of anterior intercondylar area of tibia
Proximal attachment – posterior medial aspect of lateral femoral condyle

23. ACL Anteriomedial band Posteriolateral band
Tight in flexion
Posteriolateral band
Tight in extension
Both are tight in extension
PL band is more tight

24. Knee Ligaments Posterior cruciate
Distal attachment – posterior aspect of posterior intercondylar area of tibia
Proximal attachment – anterior inferior lateral aspect of medial femoral condyle

25. Role of Cruciate Ligaments
Bring about normal movement between articular surfaces
ACL – prevents anterior displacement of tibia relative to femur
Prevents medial rotation
PCL – prevents posterior displacement of tibia relative to femur

26. Posterior Knee Ligaments
Oblique popliteal ligament
Runs from posterior aspect of the lateral condyle of femur to posterior edge of medial condyle of the tibia
Protects against hyperextension

27. Posterior Knee Ligaments
Arcute ligament
Runs from the posterior aspect of the lateral condyle to the posterior surface of capsular ligament
Protects against hyperextension

28. Ligamentous Stability in General
Not constant throughout ROM
Knee extended most stable
Knee flexed least stable

29. Patellofemoral Restrains

30. Forces Acting on the Patella

31. Q Angle Pull angle of the quadriceps 8 – 17 degrees is normal
Increased angles associated with patellofemoral problems

32. Knee Alignments
Genu valgum
Genu varum
Genu recurvatum

33. Knee Function Dual role of mobility and stability Gait and hamstrings
Mobile enough to allow movement
Stabile enough to absorb forces
Gait and hamstrings

34. Muscles Covered With the Hip
Sartorius
Rectus Femoris
Tensor Facia Lata
Gracilis
Biceps Femoris
Semitendinosis
Semimembranosus
See book for review

35. Vastus Medialis
O: lower ½ of intertrochanteric line, medial lip of linea aspera, upper part of medial supracondylar line, medial intermuscular septum, tendon of adductor magnus and longus
I: medial border of patella , through patellar ligament to tibial tuberosity
A: extends the leg at the knee and draws patella medially

36. Vastus Intermedius
O: proximal 2/3 of the anterolateral surface of femur, lower ½ of the linea aspera, upper part of lateral intermuscular septum
I: by tendons of rectus femoris and vasti muscles into superior border of patella, through patellar ligament to tibial tuberosity
A: extends leg at knee

37. Vastus Lateralis
O: upper part of intertrochanteric line, anterior and lower borders of greater trochanter, lateral lip of gluteal tuberosity, upper half of linea aspera, lateral intermuscular septum, and tendon of the gluteus maximus
I: lateral border of patella and through patellar ligament to tibial tuberosity
A: Extends leg at knee and draws patella leterally

38. Popliteus
O: lateral condyle of femur, outer margin of lateral meniscus, arcuate popliteal ligament and capsule of knee joint
I: posterior surface of tibia above soleal line
A: rotates the tibia medially on the femur, or the femur laterally on the tibia (depends on the one fixed)

39. Gastrocnemius
O: lateral condyle and posterior surface of femur, capsule of knee joint. Medial condyle and adjacent part of femur
I: posterior surface of calcaneus by means of achilles tendon
A: flexes leg at the knee, plantar flexion and inversion of foot

40. Muscle Action Around the Knee
All create stability of joint
Hamstrings help prevent ATD
2-Joint arrangement provides efficiency of movement
2-joint arrangement can lead to problems
Passive insufficiency
Active insufficiency

41. Knee Extensor Mechanism

42. Biomechanical Considerations of Knee Extension

43. Knee Instability Knee is prone to instability and injury
Continuous stress
Beyond limit of ROM
Rotation with foot fixed
Most rotation with knee flexed
Mobile adapter for twisting/turning

44. Deep Squats Safety dependent on how performed
Ability of knee to absorb forces dependent on:
Speed of descent
Size of calves and thighs
Strength of muscles controlling movement

45. Deep Squats
Dangerous when center of knee rotation is changed because of calf and thigh tissues pressing together
Lean forward at trunk to adjust center of gravity towards knees
Muscle strength