Download بسم الله الرحمن الرحيم

‫بسم اهلل الرحمن الرحيم‬
RHS 433
CLINICAL ROTATION
Credit: 3 hour
Dr. Ali Aldali, MS, PT
Tel# 4693601
Department of Physical Therapy
King Saud University
Patellofemoral Biomechanics:
Function of the Patella
• Increase the
moment arm of the
quadriceps
(extensor
mechanism)
• Provide anterior
protection of tibiofemoral joint
Patellofemoral Biomechanics:
Patellofemoral Contact Areas
• Area goes from
distal to proximal on
surface of patella as
the knee is flexed
• Area becomes
larger as knee is
flexed
• No contact from 0 to
about 15 degrees
Patellofemoral Biomechanics:
Joint Reaction Forces During Open
Chain Leg Extension, Free Weight
• Increased flexion moment arm of gravity or external
resistance
• Increased quadriceps force
• PFJR force peaks at 350
• Decreased contact area results in increasing contact
stress from 90 to 200 of flexion
Moment Arm of
Gravity
Patellofemoral Biomechanics:
Joint Reaction Forces During Closed
Chain Knee Flexion (Squat)
• Increased flexion moment
arm of gravity or external
resistance
• Increased quadriceps force
• Increased PFJR
• Increased contact area
partially off-sets increasing
PFJR to minimize increase
in contact stress
Patellofemoral Biomechanics: PF
Contact Stress During Open and Closed
Chain Knee Extension and Flexion
• PFJR & contact stress
greater with OKC from 0 to
450 (Free weight)
• PFJR & contact stress
greater with CKC from 45 to
900
Patellofemoral Alignment:
Superior/Inferior
Fused
Epiphyseal
Plate Line
Blumensatt’s
Line
Insall-Salvati: 1:1 ratio of
patellar length and patellar
tendon length. Normal ratio
range from 0.8 to 1.2
Patella should sit
between these two lines.
Patella Alta and Baja (Inferna)
Alta
Baja
Patellofemoral Alignment: Frontal
Plane Rotation (Patellar Tilt)
• Excessive lateral tilt
may occur from
shortening of lateral
retinacular tissue,
ITB, etc.
Patellofemoral Alignment: Frontal
Plane Displacement (Bisect Offset)
Line EF represents
the patellar width.
Line CD projects
through the deepest
portion of the
trochlear groove.
Bisect offset is
expressed as a
percentage of the
length of line EF that
lies laterally to line
CD.
Patellofemoral Tracking
• Inferior with flexion
• Superior with
extension
• Also some medial and
lateral gliding
occuring with inferior
and superior gliding
Effect of the Quadriceps on
Patellofemoral Tracking
• Compressive load
from quad
contraction creates
stability
• VMO functions to
counter lateral
vector from
remainder of quads
(Lieb and Perry 79)
Where Does Patellofemoral Pain
Come From?
• Retinacular Tissues?
– Excessive tension on lateral retinaculum may
cause irritation or inflammation
– Fulkerson (1985) reported neuromatous
degeneration of small nerve fibers in tight
lateral retinacular tissue
Where Does Patellofemoral Pain
Come From?
• Other Possibilities
–
–
–
–
Patellar tendon, fat pad
Medial Plica
Osteochondral Lesions
Synovial impingement (Odd facet syndrome)
Patellofemoral Dysfunction
• Blunt Trauma
• Malalignment or Mal Tracking
• Excessive Compression
Patellofemoral Dysfunction
• Anterior knee pain
• Usually gradual onset
• Painful Activities
– ascending and descending stairs
– prolonged positioning with knee flexed
– jumping, quick stop and starts
• More common in adolescent females
• Also common in young and middle-aged
active adults
Differential Diagnoses
•
•
•
•
•
•
Medial Plica Syndrome
Meniscal Injury
Patellar Tendon/Fat Pad Injury
Quadriceps Tendon Injury
IT Band Syndrome
Osteochondritis Dissecans/Chondral
Fracture
• PCL injury
P-F Dysfunction: Contributing
Factors
•
•
•
•
Bony Structural Abnormalities
Soft Tissue Restrictions
Quadriceps Femoris Dysfunction
Gluteus Medius Weakness
Flattened Lateral Condyle
Patella Alta
Patella Inferna (Baja)
Lower Extremity Malalignments
Restricted Lateral Restraints
ITB (Ober) Test and Stretch
Medial Patellar Glide
Restricted Rectus Femoris
Restricted Hamstrings
Restricted Gastrocnemius
Open vs. Closed Chain
Exercise
•
•
PFJR & contact stress greater with OKC from 0 to 450
PFJR & contact stress greater with CKC from 45 to 900
General LE Stengthening Ex
• Early Rehab
–
–
–
–
–
quad sets
SLR
1/2 squats
Lateral step ups
leg extensions with
theraban 90-45
• Later Rehab (PRE)
– Leg extensions 90-45
– Leg Press 0-45
– Leg Curls 0-90
Hip Abduction/Lateral Rotation
Weakness
• May result in excessive medial rotation
of femur during stance
• May result in excessive valgus at knee
• May increase Q angle
• May result in tracking and alignment
problems
SIDE-LYING ABDUCTION
ABDUCTION WITH PILATES
DEVICE
Single leg hip and pelvic control
Reverse Action Hip
Abduction
Single Leg Lateral Step
Down
RESISTED STANDING
EXTERNAL ROTATION
General Treatment Guidelines for
PF Dysfunction
•
•
•
•
•
•
Foot orthotics if associated with sx
Stretching of restricted soft tissues
Strengthening of quads in limited arc
Strengthening of hip abd/later rot
Functional activity modifications
Patellar taping or bracing
IT Band Syndrome
(Runner’s Knee)
• Pain and irritation of
IT band from
increased friction
over lateral femoral
epicondyle.
• Common in distance
runners.
IT Band Syndrome
(Runner’s Knee)
• Anterior, lateral knee pain, gradual onset,
associated with running or walking, descending
stairs
• Tenderness over anterior tibial tubercle
(Gurdy’s)
• Increased skin temp and swelling
• + Ober’s test
• Symptoms reproduced with knee with knee
flexion/ext, resisted contraction of tensor facia
latae
Patellar Tendinitis/Tendinosis
(Jumper’s Knee)
• Excessive tension
through tendon
results in irritation
• Associated with
deceleration activities
(landing, quick stops,
sprints)
Patellar Tendinitis/ Tendinosis
(Jumper’s Knee)
• Gradual onset of pain, associated
with jumping, quick stops, sprinting
• Tenderness,  skin temp and
swelling
• Pain reproduced with resisted quad
contraction or passive stretching of
quads.
Osgood- Schlatter Disease
• Partial or complete
avulsion of growing
tibial tubercle
• Boys more commonly
affected than girls
• Usually occurs when
participating in
jumping, cutting,
running activities
Osgood- Schlatter Disease
• Pain in region of tibial tubercle
• Aggravated with jumping, squatting, and
kneeling
• May lead to patella alta
• Usually treated conservatively, pain
dictating degree of participation in sports
• Generally resolves in 12-18 months
Sinding -Larsen-Johansson
Disease
• Persistent traction
on immature inferior
pole leading to
calcification and
ossification
• More common in
boys
• Usually occurs
when participating
in jumping, cutting,
running activities
Thank you