1. Kinesiology of
the Hip & Knee
A report by:
Kenneth Pierre M. Lopez

2. The Hip Joint Complex

3. Hip Anatomy Overview
Hip Examination Review

4. Hip joint
A.k.a. coxofemoral jt.
ROM
 Flex 0-1200
 Hypertext 0-100
 Abd 0-450
 Add across 30-400
 ER 0-450
 IR 0-350
Close-packed
 Full ext, IR, Abd

5. Hip joint
 Open-packed
 300 flex
 300 abd
 Slight ER
 Capsular pattern
 Flex, abd, IR
 End feel
 Flex soft/firm
 Ext firm
 Abd soft/firm
 Add soft/firm
 IR firm
 ER firm

6. End Feels
 Normal:
 Flexion & Adduction
 Elastic or Tissue Approximation
 SLR
 Elastic
 Extension & Abduction
 Elastic/Firm
 IR & ER
 Elastic/Firm

7. Hip joint
 Tonic labyrinthine & optical
righting reflexes
 Head effectively behaves as if
it’s fixed in a vertical position
 Maintains head over BOS
 When hip flexor ms. Is tight,
keep LOG w/in BOS
 Open-chain response =
displacement of head from
vertical (Fig. A)
 Closed-chain response =
maintain head in upright
position (Fig. B)

8. Hip joint
 Acetabulum of pelvis + head of femur
 Diarthrodial, ball-and-socket jt. w/ 30 freedom:
 flex/ext in sagittal plane
 abd/add in frontal plane
 IR/ER in transverse plane
 10 function of hip
 To support wt. of head, arms & trunk (HAT)
 Also provides pathway for transmission of forces
bet. Pelvis & LEs
 Hip tends to operate in a closed kinematic chain
 Proximal end = head
 Distal end = foot

9. Structure
Acetabulum
 Concave socket
 Lateral, inferior, anterior (LIA)
 Roundness ↓ w/ age
 Inferior = acetabular notch
 Central/deepest part = acetabular fossa
 Anteversion = anterior orientation of acetabulum
 Men = 18.50
 Women = 21.5 0
 Pathologic ↑ = ↓ jt. stability, risk for anterior dislocation of
femoral head

10. Structure
 Acetabular labrum
 Fibrocartilage rimming entire periphery
 Transverse acetabular ligament
 Roof of tunnel passage for blood vessels & nerves entering hip
 Has Center Edge angle (CE) or angle of Wiberg
 Men = 380
 Women = 350
 Smaller CE angle (more vertical) = ↓ coverage of head of
femur, ↑ risk superior dislocation of femoral head
 ↑ w/age

11. Pelvis
 1/5 pubis
 2/5 ischium
 2/5 ilium
 Pelvis full
ossification = 15-
25 y.o.

12. Femur
 Circular
 Smaller in women
 Fovea
 Inferior to medial pt. of femoral
head
 Attachment of ligament of
femoral head
 Medially, superiorly,
anteriorly (SAM)
 Neck = 5cm long

13. Femur
 Angulation
 Angle of inclination
(medial)
 Frontal plane bet.
Femoral neck & shaft
 Early infancy = 1500
 Adult = 1250
 Elderly = 1200
 ↓ in women due to width
of female pelvis
 Pathologic ↑ = coxa
valga
 Pathologic ↓ = coxa vara

14. Femur
 Angle of torsion
 Transverse plane bet. Femoral neck &
condyles
 Anterior torsion =relative lateral rotation
 ↓ w/age
 Newborn = 400
 Adult = 150
 Anteversion
 Pathologic ↑
 Internal femoral torsion
 ↓ ER
 ↑ IR
 Retroversion
 Pathologic ↓
 External femoral torsion

15. Femur
 Frog-leg position
 FABER
 True physiologic position of hip
 A congruent fit under low load would lead to
incongruence under high load
 Periphery of acetabulum in contact, fossa is non-
articular

16. Hip capsule & ligaments
 capsule has major contribution to
stability
 femoral neck = intracapsular
 greater & lesser trochanters =
extracapsular
 thickened anterosuperiorly
 thin & loose posteroinferiorly
 Iliofemoral ligament
 Y ligament of Bigelow
 Origin = AIIS
 2 arms fan out to insert = intertrochanteric
line of femur
 Strongest ligament of hip
 Taut in hyperextension
 Superior fibers taut in adduction
 Inferior tense during abduction

17. Hip capsule & ligaments
 Pubofemoral ligament
 Origin = anterior pubic ramus
 Insertion = anterior intertrochanteric
fossa
 Taut in hip abd & ext
 Ischofemoral ligament
 Origin = posterior acetabular rim,
acetabulum labrum
 Insertion = spiral around femoral
neck
 Spiral fibers taut during ext, loosen
in flex

18. Hip capsule & ligaments
 Position of stability
 Full extension of hip
 Position of vulnerability
 Flex & add (such as sitting
w/thighs crossed)
 Ligamentum teres
 Triangular
 Ligament of head of femur

19. Wt. bearing @ hip joint
 Medial trabecular system
 Medial cortex of upper femoral shaft
 Vertically oriented
 Medial accessory system is @ medial aspect of upper femoral
shaft & fans out to greater trochanter
 Lateral trabecular system
 Lateral cortex of upper femoral shaft
 Responds to forces created during contraction of abductors &
tendency of head/neck to bend as wt. is accommodated
 Lateral accessory trabecular system runs parallel w/ greater
trochanter
 Zone of weakness
 Thin trabeculae, do not cross each other
 @ femoral neck

20. Arthrokinematics
 Movement of convex femoral head on concave
acetabulum
 Femoral head glides opposite motion of distal femur
 Flex = Head spins posterior
 Ext = anterior spin
 When wt. bearing
 Femur fixed, concave acetabulum moves over convex femoral
head
 Acetabulum glides in same direction

21. Hip Mobilization
 Flexion: Femur rolls superior & glides inferiorly on pelvis
 Extension: Femur rolls inferior & glides superior on
pelvis
 Abduction: Femur rolls lateral/superior & glides inferior
on pelvis
 Adduction: Femur rolls medial/inferior & glides superior
on pelvis
 Internal Rotation: Femur rolls medial & glides lateral on
pelvis
 External Rotation: Femur rolls lateral & glides medial on
pelvis

22. Osteokinematics
 Flexion = 900 w/ knee extended
 Normal gait on level ground requires
 300 hip flexion
 100 hyperextension
 50 abd/add/IR/ER
 Anterior pelvic tilt
 Sagittal plane
 Hip flexion
 ASIS anteriorly & inferiorly, symphisis down

23. Osteokinematics
 Posterior pelvic tilt
 Hip extension
 Symphisis pubis up
 Posterior pelvis closer to femur
 Lateral pelvic tilt
 Frontal plane
 One hip joint serves as pivot/axis
 Opposite iliac crest elevates (hip hike) or drop (pelvic drop)
 Reference is side farthest from supporting hip
 Pelvic rotation
 Transverse plane
 Occurs in single-limb support around axis of supporting hip jt.
 Forward rotation
 Side opposite supporting hip moves anteriorly
 Backward rotation
 Side opposite supporting hip moves posteriorly

24. Osteokinematics
 Lumbar-Pelvic Rhythm
 Open-chain
 E.g. reaching the floor
 Hip flexion up to 900 only
 Anterior tilt of pelvis on femurs
 Flexion of lumbar spine adds 450
 E.g. side-lying abduction
 Lateral tilt of pelvis & lumbar spine adds 450
 Closed chain response to motions of pelvis
 Keeps one or both feet on the ground
 Maintain head upright & vertical
 Anterior pelvic tilt during hip flexion = head & trunk displaced
forward + lumbar extension
 Posterior pelvic tilt + lumbar flexion to keep head forward over
sacrum

25. Osteokinematics
pelvic motion co-hip motion
compensatory
lumbar
anterior tilt hip flex lumbar ext
posterior tilt hip ext lumbar flex
lateral tilt (drop) right hip add right lateral flex
lateral tilt (hike) right hip abd left lateral flex
forward rot right hip IR rotation to left
backward rot right hip ER rotation to right

26. Hip jt. Musculature
Flexors
10
Iliopsoas
 O = iliac fossa, lateral sacrum,
IVD & bodies of T12-L4
vertebra, transverse process
of L1-L5
 I = lesser troch
Rectus femoris
 O = AIIS
 I = tibial tuberosity
 Hip flexion w/knee flexed

27. Hip jt. Musculature
Tensor fascia lata
O = anterolateral lip of iliac crest
I = iliotibial band
Abd, IR femur
Maintain tension @ iliotibial band (relieves stress
on femur)
Sartorius
Straplike
O = ASIS
I = upper medial tibia
Flex & abduct hip in either knee flex/ext

28. Hip jt. Musculature
20 = 40-500 flexion
Pectineus
Adductor longus
Adductor magnus
Gracilis

29. Hip jt. Musculature
 Adductors
 Pectineus
 O = superior ramus pubis
 I = femur, below lesser troch
 Medial to iliopsoas
 Adductor brevis, longus &
magnus
 O = inferior ramus & body pubis
 I = linea aspera
 Anteromedially located
 Gracilis
 O = symphysis pubis
 I = medial surface tibial shaft

30. Hip jt. Musculature
Extensors
Gmax
 O = sacrum, dorsal sacroiliac
ligaments, ilium
 I = superior fibers into iliotibial
band, inferior fibers into gluteal
tuberosity
Hamstrings
 O = ischial tuberosity
 I = biceps femoris into head of
fibula, Semimem & ten into medial
tibia

31. Hip jt. Musculature
Abductors
Gluteus medius
 O = lateral wing of ilium
 I = greater troch
 Anterior fibers flex & IR
 Posterior ext & ER
 All abduct
Gluteus minimus
 O = outer ilium
 I = greater troch
 Stabilize pelvis in unilateral stance

32. Hip jt. Musculature
 Lateral Rotators = all insert into greater
troch
 Obturator internus
 O = inside of obturator foramen
 Obturator externus
 Close to gemelli
 Gemellus superior
 O = ischial spine
 Gemellus inferior
 @ inferior border of obturator internus
 Quadratus femoris
 O = Ischial tuberosity
 I = posterior femoral head
 Piriformis
 O = anterior sacrum
 Superior to sciatic nn

33. Hip jt. Musculature
 Medial rotators
 Anterior gluteus medius
 Tensor fascia lata

34. Hip jt. Pathology
 Arthrosis
 OA
 Tissue changes in aging
 Fx
 Due to abnormal ↑ of magnitude of force or weakening of bone
 Usually @ zone of weakness
 Femoral neck
 Bony abnormalities of femur
 Coxa valga
 Functionally weakened abductors
 ↓ hip stability
 Predispose to hip dislocation

35. Hip jt. Pathology
 Coxa vara
 ↑ hip stability
 Femoral head deeper in acetabulum
 ↑ risk for femoral neck fx
 Slipped capital femoral epiphysis = slide femoral head inferiorly
 Retroversion
 stable
 Out-toeing
 Anteversion
 Unstable, predispose to andterior dislocation of head of femur
 In-toeing
 Hip abductors fall posterior, functionally weak
 Paraplegia
 Y ligament permits standing balance when knee & ankle
stabilized w/ orthosis

36. The Knee Joint Complex

37. Knee Joint Overview
Knee Examination Review

38. Knee Joint
 3 bones
 Femur, tibia, patella
 3 articulating surfaces
 Medial tibiofemoral, lateral tibiofemoral, patellofemoral all
enclosed in the joint capsule
 Mobility is primarily by the bony structure
 Stability is primarily by the soft tissues
 * the knee complex is responsible for moving and
supporting the body in sitting and squatting activities and
for support for transfers and locomotive activities

39. Knee Joint
 A double condyloid joint with 2degrees of freedom
 Flexion and extension / Medial and lateral rotation
 0-120-150 degrees for flexion; Hyperextension 15 degrees

40. Ligamentum
patellae
Continuation of the tendon of the
quadriceps femoris muscle
Attached above to the lower
border of the patella and below to
the tubercle of the tibia
Gives the patella is mechanical
leverage

41. Lateral Collateral Ligament
 Aka fibular collateral ligament
 Cordlike structure attached to the lateral condyle of the
femur and below to the head of the fibula
 Separated from the lateral semilunar cartilage by the
tendon of popliteus muscle
 Taut during full knee extension & slack during full knee
flexion
 Protects the lateral side from an inside bending force (a
varus force).

42. Stabilizing role of the
lateral collateral ligament
Primary restraint to
adduction of the knee
Secondary restraint to
anterior and posterior
drawer, when the drawer
displacements are large.
Combined with the other
lateral structures the
lateral collateral ligament
is a significant restraint to
external rotation of the
tibia.

43. Medial Collateral Ligament
 Flat band that is attached above the medial condyle of the
femur and below to the medial surface of the shaft of the tibia
 Strongly attached to the medial semilunar cartilage
 Taut during full knee extension and slack during full knee
flexion
 Composed of three groups of fibers, one stretching between
the two bones, and two fused with the medial meniscus.
 Partly covered by the pes anserinus and the tendon of the
semimembranosus passes under it
 Protects the medial side of the knee from being bent open by
a stress applied to the lateral side of the knee (a valgus
force).

44. Medial collateral ligament
functional units
The medial collateral
ligament is the primary
restraint to abduction and
internal tibial rotation.
Secondary role of MCL:
Provides anterior knee
stability, which is enhanced
by external tibial rotation.
With anterior cruciate
disruption the medial
collateral ligament provides
most of the anterior stability
of the knee.

45. Oblique Popliteal Ligament
 Tendinous expansion of the semimembranosus muscle
 Strengthens the back of the capsule

46. Anterior Cruciate Ligament
 Attached below to the anterior intercondylar area of the tibia
 Courses superiorly, posteriorly & laterally; attaches to the
lateral femoral condyle
 Prevents anterior dislocation of the tibia on a fixed femur or
prevents posterior dislocation of the femur on a fixed tibia
 Checks lateral rotation of the tibia in flexion and to a lesser
extent, check extension & hyperextension at the knee
 Helps to control the normal rolling and gliding movement of
the knee
 Anteromedial bundle is taut in both flexion & extension, while
the posterolateral bundle is taut on extension only

47. ACL:
Primary restraint to anterior
translation of the tibia and
contributes the most at 30°
flexion.
-Prevents hyperextension of
the knee
- Secondary restraint to
internal tibial rotation
- Resists adduction and
abduction at full extension
- 'guides' the screw home
rotation of the knee joint as it
approaches terminal
extension

48. Posterior Cruciate Ligament
 Attached below to the posterior intercondylar area of the
tibia
 Courses superiorly, anteriorly and medially; attaches to
the medial femoral condyle
 Stoutest ligament in the knee
 Prevents posterior dislocation of the tibia on a fixed
femur or prevents anterior dislocation of femur on a fixed
tibia
 Checks extension & hyperextension, and in addition,
helps to maintain rotary stability and functions as the
knee’s central axis of rotation
 Bulk of the fibers are tight at 30 degrees flexion and the
posterolateral fibers are loose in early flexion

49. PCL:
Primary restraint
posterior translation of
tibia
Secondary restraint
external tibial rotation
at 90° flexion, which
reduces upon knee
extension
Near full knee extension, the
anterior bundle of the PCL
slackens, and the
posterolateral structures
become the primary restraint.

50. PCL footprint
No fan out like the
ACL
The fibers are almost
parallel to bone

51. Meniscofemoral Ligaments
 The ligaments of Humphrey and Wrisberg are
meniscofemoral ligaments which run from the
posterior horn of the lateral meniscus to the lateral
aspect of the medial femoral condyle
 The anterior meniscofemoral ligament is known as
the ligament of Humphrey
 The posterior meniscofemoral ligament is known as
the ligament of Wrisberg
 In about 70 % of knees, there is either anterior
meniscofemoral ligament of Humphrey or posterior
meniscofemoral ligament of Wrisberg

52. Humphrey ligament: (anterior meniscofemoral)
 is less than 1/3 the diameter of the PCL
 arises from the posterior horn of the lateral meniscus,
runs anterior to the to the PCL and inserts at the distal
edge of the femoral PCL attachment
Wrisberg's ligament: (posterior
meniscofemoral)
 usually larger than ligament of Humphrey (upto 1/2 the
diameter of the PCL diameter)
 extends from the posterior horn of lateral meniscus to
medial femoral condyle

53. Semilunar Cartilages (Menisci)
 Sheets of fibrocartilage with a thick peripheral
convex border and a thin inner concave border
which is attached to the capsule
 Upper surfaces are in contact with the femoral
condyles and the lower surfaces are in contact with
the tibial condyles
 Increase the congruency of the tibiofemoral
articulations & distribute the pressure
 Lateral meniscus is “O” shaped
 Medial meniscus is “C” shaped and is thicker
posteriorly than anteriorly

54. MENISCUS:
Lateral meniscus
Medial meniscus
Transverse meniscal ligament
Posterior menisco-meniscal
ligament
Anterior/Posterior horn
-attached to intercondylar tibial
plateau
-vascular like periphery

55. Meniscal biomechanics and
Functional anatomy
Medial meniscus has a firm bond
to MCL
Lateral meniscus has no
attachment to LCL
Because the popliteus tendon
attaches to the posterolateral
corner of the lateral meniscus,
there is some additional mobility
and decreased vascularity in this
location.
The transverse ligament joins the
anterior horns of the two menisci.

56. Synovial Membrane
Lines the capsule
Forms a pouch that extends up beneath the
quadriceps femoris to form the suprapatellar
bursa, anteriorly
Extends downward on the tendon of the
popliteus muscle forming the popliteal bursa,
posteriorly

57. Bursa Related to the Knee Joint
Suprapatellar Bursa
Lies beneath the quadriceps muscle
Largest bursa and always communicates with
the knee joint
Prepatellar Bursa
Lies between the patella and the skin
Infrapatellar Bursa
Superficial infrapatellar bursa: lies between the
ligamentum patellae & the skin
Deep infrapatellar bursa: lies between the
ligamentum patellae and the tibia

58. Suprapatellar, Prepatellar, Infrapatellar Bursae

59. Popliteal Bursa
Surround the tendon of the popliteus; always
communicates with the joint cavity
Semimembranosus Bursa
Lies between the tendon of this muscle and the
medial condyle of the tibia
May communicate with the joint cavity

60. The Screw Home Mechanism
 Refers to the terminal external rotation of the leg at the last 20
degrees of extension due to unequal condylar configuration,
muscle torque action & ligamentous guidance
 During the last 20 degrees of knee extension, the tibia
externally rotates about 20 degrees on the fixed femur
 Also called the terminal rotations of the knee
 In closed kinematic chain motion, terminal rotation is seen as
internal rotation of the femur on the fixed tibia
 In open kinematic chain motion, terminal rotation is seen as
the external rotation of the tibia on a fixed femur
 Rotation between the tibia and femur occurs automatically
between full extension (0˚) and 20˚ of knee flexion. These
figures illustrate the top of the right tibial plateau as we look
down on it during knee motion.

61. DURING KNEE
EXTENSION, the tibia
glides anteriorly on the
femur.

62. During the last 20
degrees of knee
extension, anterior
tibial glide persists on
the tibia's medial
condyle because its
articular surface is
longer in that
dimension than the
lateral condyle's.

63. Prolonged anterior
glide on the medial
side produces external
tibial rotation, the
"screw-home"
mechanism.

64. The Screw Home Mechanism
Reverses during knee
flexion
When the knee begins
to flex from a position
of full extension,
posterior tibial glide
begins first on the
longer medial condyle.

65. Between 0 deg.
extension and 20 deg.
of flexion, posterior
glide on the medial
side produces relative
tibial internal rotation,
a reversal of the
screw-home
mechanism.

66. Closed Kinematic Chain Motion
 Aka proximal-on-distal segment kinematics
 A series of segment link motion with the distal end fixed
on the ground or some immovable point e.g. standing
up, squatting down
Open Kinematic Chain Motion
 Aka distal-on-proximal segment kinematics
 A series of segment link motion with the distal end free in
space e.g. raising lower leg, throwing a ball
Kinematics
 A branch of mechanics that describe the position and
motion of body in space, without regard to the forces or
torques that may produce the motion

67. Osteokinematics
 Normal ROM: Flexion >130 Rotation: 10
 OPP: 25 flexion
 CPP: Maximal Extension &tibial external rotation
 Normal End feels
 Flexion: Tissue approximation
 Extension: Elastic/Firm
 SLR: Elastic
 *Femoral condyles begin to contact the patella inferior at 20 of
knee; flexion; progresses superior at 90 & medial/lateral at 135
of knee flexion

68. Arthrokinematics
 Concave Surface: Tibial Plateau
 Convex Surface: Femoral Condyles
 To facilitate extension:
 OKC: tibia rolls and glides anterior on femur
 CKC: femur rolls anterior and glides posterior on the tibia
 To facilitate knee flexion:
 OKC: tibia rolls & glides posterior on the femur
 CKC: femur rolls posterior and glides anterior on the tibia

69. Functions of Knee
Muscles & their
Change of Actions

70. Leg movements by compartment (in leg all
nn are branches of sciatic)

71. Anterior Leg (deep fibular n.)
Fibularis (peroneus)
longus
Extensor digitorum
longus
Extensor hallicus
longus
Tibialis anteriorus

72. Lateral Leg (superficial fibular n.)
Fibularis
brevis/longus

73. Posterior Leg (tibial n.)
Gastrocs and soleus
Flexor digitorum
longus
Flexor hallucus
longus

74. Vastus Intermedius
Most efficient knee extensor
with least demand of force

75. Vastus Medialis
Plays an important role in
keeping the patella on track in
gliding on the femoral condyles
(tracking mechanism)

76. Vastus Medialis Oblique
 The medially directed
forces of the VMO
counteract the laterally
directed forces of the
vastus lateralis, thus
preventing lateral
displacement of the
patella in the trocklear
groove

77. Biceps Femoris
Externally rotates the tibia with
respect to the femur

78. Popliteus
Considered as knee flexor
but has a poor leverage for
this motion
Medially rotates the tibia on
the femur to initiate
unlocking of the flexed knee

79. Quadriceps Muscles
When coming to standing from
sitting position, these act
concentrically to extend the
knee
When coming to sitting from
standing position, these act
eccentrically to control the rate
of knee flexion

80. Gastrocnemius
Flexes the knee
simultaneous with
plantar flexion of the
ankle

81. Knee Alignment & Deformities
 Tibio-femoral shaft angle is seen anteriorly on an
extended knee which is about 170 degrees in a
normal adult
 Genu Valgum or Knock Knee: refers to an angle
that is less than 170-165 degrees >195 if ant
 Genu Varum or Bowleg: refers to an angle that
approaches 180 degrees or greater <180 if ant
 Q Angle: an angle formed by the tendons of the
quadriceps femoris and ligamentum patellae; N= 15˚
 Genu Recurvatum: an excessive hyperextension
that develops from weight bearing on an unstable
knee