2. Objectives
Able to:
Know and describe the type of joint
Know and describe the articulations of the knee joint
Know the muscle origin, insertion, nerve supply and
describe actions they perform at the knee joint.
The structures of the knee joint including ligaments,
meniscus and bursae.
Know and describe the nerve, arterial and venous supply at
the knee.
Know and describe the different movements of the knee.
Know and describe application of biomechanics and
kinematics of the knee joint in Physiotherapy diagnosis,
treatment and rehabilitation.
3. Introduction
Function
• To allow locomotion with minimum energy
requirements from the muscles and stability,
accommodating for different terrains.
• To transmit, absorb and redistribute forces
caused during the activities of daily life
4. Type of Joint
The knee is classified as a;
1. Synovial /diarthroses- a freely moveable
joint.
2. Uniaxial joint- does only 1 degree of
movement.
3. Hinge joint- moves in one plane with slight
rotational movement, but the rotation is not
enough to be considered significant.-
5. Articulations
The knee (art. Genu)
Type of joint: hinge joint
Articular surface:
• Tibiofemoral joint
• Patellafemoral joint
6. Tibiofemoral joint
Articulation surfaces;
Femur
The articular surface of
medial and lateral
condyles articulates with
the distal end of tibia.
Anteriorly patellar
groove allows
engagement of the
patella during early
flexion.
7. Tibiofemoral joint
Tibia articulation
Tibial plateaus are
predominantly flat
Slight convex at the
anterior and posterior
margins
Because of this lack of
bony stability, menisci
are necessary to improve
joint congruency.
10. Ligaments
The stability of the knee is due mainly to the
ligaments.
A ligament is several large fibrous bands of
tissue, comparable to that of a rope, they
support the knee on both sides and front to
back. Ligaments connect bone to bone.
11. Ligaments
The ligaments may be divided into those that lie outside the capsule
and those that lie within the capsule.
Extra Capsular Ligament
• Ligamentum Patella
• Lateral Collateral Ligament
• Medial Collateral Ligament
• Oblique Popliteal Ligament
Intra Capsular Ligament
• Anterior Cruciate Ligament
• Posterior Cruciate Ligament
• Ligaments of the menisci;
Coronary (Meniscotibial)
Ligament
Transverse Ligament
12. Extra Capsular Ligament.
• Ligamentum Patella
Attached above to the lower border of the patella and below to the
tuberosity of the tibia.
Continuation of the central portion of the common tendon of the
quadriceps femoris mm.
• Lateral Collateral Ligament
Cord like and is attached above to the lateral condyle of the femur and
below to the head of the fibula.
The tendon of the popliteus mm intervenes between the ligament and the
lateral meniscus.
• Medial Collateral Ligament
A flat band and is attached above to the medial condyle of the femur and
below to the medial surface of the shaft of the tibia .
It is firmly attached to the edge of the medial meniscus.
• Oblique Popliteal Ligament
A tendinous expansion derived from the semimembranosus mm.
It strengthens the posterior aspect of the capsule.
13. Intracapsular Ligament.
• Cruciate Ligaments
Two strong Intracapsular ligaments that cross each other within the joint cavity.
They are named anterior and posterior according to their tibial attachment.
i. Anterior Cruciate Ligament
Attached to the anterior intercondylar area of the tibia and passes upward,
backward and laterally to be attached to the posterior part of the medial surface
of the lateral femoral condyle.
Prevents posterior displacement of the femur on the tibia.
With the knee joint flexed, the ACL prevents the tibia from being pulled anteriorly.
ii. Posterior Cruciate Ligament
Attached to the posterior intercondylar area of the tibia and passes upward,
forward and medially to be attached to the anterior part of the lateral surface of
the medial femoral condyle.
Prevents anterior displacement of the femur on the tibia.
With tibiofemoral joint flexed, the PCL prevents the tibia from being pulled
posteriorly.
15. Menisci
• Meniscus- is a
crescent shaped
fibrocartilaginous
structure that, in
contrast to articular
discs, only partly
divides a joint cavity.
–Medial meniscus
–Lateral meniscus
16. Bursae
• Bursae -A closed sac
lined with a synovial
membrane and filled
with fluid, usually found
in areas subject to
friction, such as where a
tendon passes over a
bone.
– infrapatellar bursa
– suprapatellar bursa
– prepatellar bursa
17. Muscles of the knee joint
1. Biceps femoris
2. Semomembranosus
3. Semitendinosus
4. Gracilis
5. Satorius
6. Tensor Fascia Lata
7. Popliteus
8. Gastrocnemius
9. Plantaris
10. Rectus femoris
11. Vastus medialis
12. Vastus lateralis
13. Vastus intermedius
18. Muscles
Muscle Origin Insertion Nerve Action
Popliteus lateral surface of
lateral condyle of
femur and lateral
meniscus
Posterior surface
of the tibia.
Tibial nerve
L4-S1
Assist knee
flexion
Gastrocnemius Lateral head:
lateral aspect of
lateral condyle of
femur.
Medial head:
popliteal surface
of femur,
superior to
medial condyle
calcaneus with
calcaneal tendon
tibial nerve
(S1,S2)
plantairflexion
ankle, flexion
knee
Plantaris inferior end of
lateral
supracondylar
line of femur
tuber calcanei tibial nerve
(L5,S1)
assists
gastrocnemius in
plantarflexion
ankle and flexing
knee
19. Muscles Origin Insertion Nerve Action
Rectus Femoris anterior inferior
iliac spine, ilium
superior to
acetabulum
base of patella,
tibial tuberosity
femoral nerve
(L2,L4)
knee extension,
flexion hip.
Vastus Medialis interthrochanteric
line and linea
aspera of femur
base of patella,
patellar ligament to
tibial tuberosity
femoral nerve
(L2,L4) .
knee extension
Vastus Lateralis intertrochanteric
line, greater
trochanter, linea
aspera .
base of patella,
lateral side of
quadriceps femoris
tendon.
femoral nerve (L2,
L3, L4)
extension of the
knee
Vastus Intermedius anterior and lateral
surfaces of body of
femur
base of patella,
patellar ligament to
tibial tuberosity
femoral nerve
(L2,L4) .
knee extension.
Biceps femoris long head: ischial
tuberosity. short
head: lower half of
the linea aspera,
and lateral
condyloid ridge.
I: head of the fibula
and lateral condyle
of the tibia
Sciatic nerve Knee flexion
20. Muscles Origin Insertion Nerve Action
Semitendinosu
s
Ischial
tuberosity
Medial surface
of tibia
Sciatic nerve Knee flexion
Semimembran
osus
Ischial
tuberosity
Medial condyle
of tibia
Sciatic nerve Knee flexion
Gracilis Ischiopubic
ramus
Upper part of
the medial
surface of the
body of tibia.
Obturator
nerve
Knee flexion
Satorius Anterior
superior illiac
spine of the
pelvic bone.
Anteromedial
surface of the
upper tibia.
Femoral nerve. Knee flexion.
Tensor Fascia
lata
anterior
superior iliac
spine, anterior
part iliac crest.
iliotibial tract
attaches to
lateral condyle
of tibia.
superior gluteal
nerve (L4,L5) .
Assists in knee
flexion.
22. Innervations
The muscles of the knee
are supplied by the
lumbosacral plexus;
• S1, S2, L2, L3,L4 and L5.
The nerves are;
• Obturator nerve
• Tibial nerve
• Femoral nerve
• Sciatic nerve.
23. Arterial and venous supply
Arteries of the knee
The main arteries supplying the knee
region are;
1. femoral,
2. popliteal,
3. anterior tibial and
4. posterior tibial arteries.
Although the popliteal artery is deep in
the popliteal fossa, the popliteal
pulse can still be felt but the knee
has to be bent and the person still
has to press deep into the fossa.
Veins of the knee
There are deep and superficial veins.
• The names of the deep veins are
the same as the names of the artery
they accompany.
• There are two important superficial
veins:
1. the great and lesser saphenous
veins.
2. The great saphenous is often used
in coronary bypass operations as it
has thicker walls than most veins
and therefore it can substitute for
an artery. (Removal of this vein
does not cause a problem as there
are still the deep veins to return
the blood to the heart).
25. Movements
Knee;
• Performs one degree of
movement.
• Flexion and Extension
• Occurs in sagital plane
in the frontal axis
26. Movements-Kinematics
Osteokinematic
The knee produces only to major
osteokinematic movements. These are primarily
the;
• Flexion- 130-140 degrees
• Extension- produces at 0 degrees whilst some
go into -5 degree of hyperextension, beyond -
5 degree it is described as genu recurvatum.
27. Movements- Osteokinematics
Extension
• During, the quadriceps
muscles contract pulling on
the quadriceps tendon,
which in turn pulls on the
patella via the patellar
tendon causing an
extension of the knee.
Flexion
• On the posterior side of the
knee the hamstring group
of muscles contract pulling
on the tendons associated
with the hamstring, pulling
on the tibia, which causes
the flexion of the knee.
29. Movements
Arthrokinematics
If suppose there is an
extension of the knee,
there is an anterior
rolling of the femoral
condyles and a
posterior sliding occurs
to bring knee into
extension.
32. • Injury /Pathology
• Physiotherapy Diagnosis
• Physiotherapy Treatment and Rehabilitation
Application of Biomechanics and
Kinesiology
33. • Medial Collateral Ligament Tear
– Knee Ligament Stability Tests - Adduction Test/Valgus
Stress Test)
• The knee is stabilized by:
• Ligament
• Menisci
• Shape and congruency of the articular surfaces
• Muscles
• The ligaments ensure functional congruency by guiding the femur and tibia and limiting
the space between them.
• Ligament injuries lead to functional impairment of the knee with instability. Knee
ligament stability tests can help to identify and differentiate these instabilities.
• Abnormal directions of motion can be divided into three categories:
1. Direct instability in a single plane
2. Rotational instability
3. Combined rotational instability
• Medial Collateral Ligament and medial stability is assessed in 20° of flexion and in full
extension.
• In 20°of flexion, the posterior capsule is relaxed.
• Screw-home mechanism
• Interlocking of femoral and tibial condyles.
• Applying a valgus stress in 15-200 flexion evaluates the medial collateral ligament alone
as the primary stabilizer.
• Full extension prevents medial opening as long as the posterior capsule and posterior
cruciate ligament are intact, even if the medial collateral ligament is torn.
Example 1. Physiotherapy Diagnosis (Special Tests)
34. Example 2. Pathology, Physiotherapy Treatment and Rehabilitation
Osteoarthritis – Total Knee Arthroplasty Replacement
Ascending Stairs
• The actual degree of knee flexion required to
ascend stairs is determined not only by the height
of the step but also by the height of the patient.
• For the standard step approximately 650 of flexion
will be required.
• In climbing stair, lever arm can be reduced by
leaning forward.
• The tibia is maintained relatively vertical, which
diminishes the anterior subluxation potential of
the femur on the tibia.
35. Cont..
Descending stairs
• In standard step 850 of flexion is required:
• The tibia is steeply inclined toward the horizontal,
bringing the tibial plateaus into an oblique
orientation.
• The force of body weight will now tend to sublux
the femur anteriorly.
• This anterior subluxation potential will be resisted
by the patellofemoral joint reaction force and the
tension which develops in the posterior cruciate
ligament.
36. Cont..
• In the absence of a posterior cruciate ligament only the collateral
ligaments are available to assist the patellofemoral joint reaction
force in providing anterior-posterior stability
• Many patients with arthritis will report difficulty descending stairs
normally, this will also be true after total knee replacement.
• A simple rehabilitation training is to have them descend either
sideways or backward which is biomechanically the equivalent of
ascending the stairs with its decreased mechanical and range of
motion demands.
37. Summary
• The knee joint is classified as a synovial
uniaxial hinge joint.
• The muscles of the knee; that primarily
contributes to movements produced are the
hamstrings and quadriceps.
• There two meniscus; medial and lateral
meniscus
• Also present at the knee is the bursae, there
three types; infrapatellar, suprapatellar and
prepatellar bursae.
38. Summary
• The articular surfaces of the knee are the;
condyles of the femur and tibia and the
posterior surface of the patellar.
• The ligaments provides stability, there are four
types; the medial collateral, lateral collateral,
anterior cruciate and posterior cruciate
ligaments.
• The nerve innervations at the muscles of the
knee joints are; obturator, femoral, tibial and
the sciatic nerve.
39. Summary
• The arteries supplying the knee are; femoral,
popliteal, anterior tibial and posterior tibial
arteries.
• The veins at the knee region are the great and
lesser saphenous veins.
• The movements; flexion and extension
(osteokinematics) & sliding and rolling
(arthrokinematics).
• The knees abnormality results from injuries
and diseases affecting its structures.
40. References
American Academy of orthopedic surgeon,
Ortho info, www.aaos.com , 28th/04/2015,
P.K Levangie et al, Joint structure and function: A
comprehensive analysis (2005), 4TH edition,
F.A. Davis Company, Philadelphia, USA
Images from PY107 Anatomy: Miss Girey’s
Presentation and from Miss Nilam’s
Orthopedic PY209 presentations.
41. Reference
D. Knudson, Foundamentals of Biomechanic (2007),
springer science, New York, USA.
Joseph H., KnutzenM., Biomechanical basis of
human movement, 2003
LevangieP, NorkinC., Joint structure & function, a
comprehensive analysis,5thed. Philadelphia, FA
Davis Company. 2011.
Premkumar K. The Massage Connection: Anatomy
and Physiology. Baltimore: Lippincott Williams &
Wilkins, 2004.
42. References
• Joseph H., KnutzenM., Biomechanical basis of
human movement, 2003
• LevangieP, NorkinC., Joint structure &
function, a comprehensive analysis,5thed.
Philadelphia, FA Davis Company. 2011.
• Premkumar K. The Massage Connection:
Anatomy and Physiology. Baltimore: Lippincott
Williams & Wilkins, 2004.
