Anatomy, Biomechanics, and Pathomechanics
of the
Hip and Knee
Ed Mulligan, PT, DPT, OCS, SCS, ATC
Relevant Anatomy of the Hip and Knee
Hip Joint Osteology-Structure
• Ball and socket joint allowing three degrees of freedom
• The acetabulum faces anterior, inferior, and lateral and is
deepened a fibrocartilaginous labrum
Bony Anatomy
Muscular Anatomy
Lumbar Vertebrae
Iliac Crest
Ilium
ASIS
Sacrum
PSIS
Pubic Symphysis
Femoral Neck
Lesser Trochanter
Femoral
Head
Greater Trochanter
Obturator
Foramen
Ischial Tuberosity
1
Muscular Anatomy
HIP Prime Movers
Thigh Prime Movers
ACTION
Muscle
Innervation
Segment
FLEXION
Tensor Fascia Latae
Iliopsoas
Rectus Femoris
Sartorius-Pectineus
Superior Gluteal
Lumbar Plexus
L4-S1
Lumbar Plexus (L1-2)
EXTENSION
Gluteus Maximus
Hamstrings
Inferior Gluteal
Sciatic
L5-S2
ADDUCTION
Adductor Magnus-LongusBrevis; Pectineus, Gracilis
Obturator
L2-4
ABDUCTION
Gluteus Medius-Minimus
Superior Gluteal
L4-S1
INT ROTATION
Gluteus Minimus
Tensor Fascia Latae
Superior Gluteal
L4-S1
EXT ROTATION
Piriformis
Obturator Int/Ext
Gemelli; Quadratus Femoris
Sciatic Branches
S1-2
“Rotator Cuff” of the Hip
ACTION
Muscle
Segment
SHOULDER MUSCLE
HIP CORALLARY
EXTENSION
Rectus Femoris;
Vastus Medialis-Lateralis- Femoral
Intermedius
L2-3
Supraspinatus
Gluteus Medius
Semimembranosus
Semitendinosus
Biceps Femoris
L5-S2
Infraspinatus
Teres Minor
Subscapularis
LH of Biceps
Gluteus Minimus
Piriformis
Iliopsoas
Rectus Femoris
Anterior Deltoid
Posterior Deltoid
Tensor Fascia Lata
Gluteus Maximus
FLEXION
Hip Innervations
Innervation
Sciatic
HIP JOINT
Frontal Plane Structure
angle of inclination of
femoral head should be 125°
Coxa Varum - angle of inclination < 120°
Coxa Valgus - angle of inclination > 135°
Coxa Valgus – decreased hip abduction
moment arm
2
Hip Anteversion-Retroversion
Transverse Plane Hip Structure
Retroverted
torsion angle of head on femoral neck
Anteversion
• Femoral Anteversion
Anteverted
–
–
Retroversion
torsion angle > 15°
toeing in
Ÿ Femoral Retroversion
– torsion angle < 8°
– toeing out
Craig’s Test and/or proportional hip ROM
to identify presence
Craig’s Test Accuracy
Hip Ante-Retroversion Consequence
ANTEVERTED
l
Good reliability
–
–
l
l
Increased femoral anteversion
shortens the abductor and
external rotator moment arms
l
Predisposes to gluteus medius
hip weakness
Intratester : ICC – 0.88-.90
Intertester: ICC – 0.83
Suspect Clinical Applicability
–
Moderate agreement between MRI and
clinical exam
–
95% CI = +12°
l
NORMAL
(ICC = 0.67-.69 with a SEM of 6°)
Souza RB, J Orthop Sports Phys Ther , 2009
continuing ED
Hip Ligaments
Hip Joint ROM
Iliofemoral resists ext/IR;
strongest ligament in body
Normal ROM
MOTION
Ischiofemoral
resists ext/IR
Pubofemoral resists abd/ext/ER
Flexion
Extension
Abduction
Adduction
External Rotation
Internal Rotation
ROM necessary
for normal gait
0-120°
0-30°
0-45°
0-30°
0-45°
0-45°
40-60°
15-20°
7°
5°
9°
4°
3
Hip Joint
accessory motions of the hip
open kinetic chain motion
closed kinetic chain motion
convex head of the femur moves in
opposite direction of joint motion
concave acetabulum moves in the
same direction as the pelvis
Resting Position
Slight Flexion (30°), Abduction (30°), and External
Rotation (20°)
Closed Pack Position
Extension, Abduction, and Internal Rotation
Knee Joint
Flexion
Extension
Abduction
femoral head rolls
femoral head rolls
femoral head moves
Adduction
femoral head moves
Int Rot
femoral head spins
posterior
anterior
inferior
(distal)
superior
(proximal)
posterior
Ext Rot
femoral head spins
anterior
Ant Pelvic Tilt
Post Pelvic Tilt
Lat Pelvic Tilt
anterior
posterior
inferior
(pelvis elevates)
Lat Pelvic Tilt
pelvis moves superior
(pelvis drops)
Fwd Pelvic Rot pelvis spins ant; R-CCW
Bwd Pelvic Rot pelvis spins post; R-CW
Function of the Knee
l
l
l
Shorten and lengthen the limb
Support the body in erect posture
– CKC - weight bearing
Move leg and foot in space
– OKC - non-weight bearing
weight bearing function
Knee “Personality”
l
l
Sacrifices stability to afford mobility
Influenced by the joints proximal and distal
to it (hip and foot/ankle)
–
–
l
Slave to the forces from above and below
Knee reacts to the forces that center on the joint
Many biarticular muscles
–
Muscles that cross both the knee and hip
or knee and ankle
pelvis rolls
pelvis rolls
pelvis moves
non-weight bearing function
Knee Structure
l
2 articulations within one joint capsule
–
Actually three but we’ll cover the superior
tibfib joint in the next session because it
functionally acts in concert with the ankle
and foot
þ Tibiofemoral Joint
þ Patellofemoral Joint
4
Femur
Notch Width
l
Medial and lateral condyles separated by intercondylar
notch and joined by patellar groove
–
–
Lateral conydyle more in line of femoral shaft (than medial
condyle)
Medical condylar surface is broader
l
–
l
l
A vs. U
Usually smaller in females
Intercondylar notch (trochlear groove) width and shape
thought to be a risk factor for ACL injury
Osgood Schlatter –
Apophysitis at the Tibial Tubercle
Medial and lateral tibial plateaus
separated by intercondylar tubercles
–
Medial plateau is 50% larger and its
articular cartilage is 3x as thick
–
Functions to transfer weight across the
knee towards the ankle
–
Tibial tuberosity is site of patellar tendon
attachment and site of apophyseal pain
in active adolescents
Fibula
l
l
Facilitates the screw home locking mechanism of the knee in
extension
Tibia
l
l
Does not directly articulate with the
femur
Non-weight bearing bone
Tib-Fib joints are functionally part of
the foot-ankle
Patella
Triangular shaped sesamoid bone
•
Resides in the intercondylar notch and
is concave from medial to lateral but
convex from anterior to posterior
base
apex
5
Patella functions as an:
l
Patella
anatomical pulley to increase the
moment arm of the quadriceps
Posterior surface has a vertical ridge dividing the
patella into medial, odd, and lateral facets which
are covered with articular cartilage
l
base
L1 > L2
apex
Knee Joint Osteology and Structure
Odd Medial
Lateral
Knee Joint Osteology and Structure
tibiofemoral and patellofemoral components
l
• Anatomically complex
– medial femoral condyle is wider AP
• screw home mechanism
medial femoral condyle projects
further distally
– creating genu valgus
– lateral femoral condyle projects further
anterior
• patellar buttress
Inner Lining of Joint Capsule
Knee Joint Osteology and Structure
l
tibial plateau has a 5-10° posterior
slope
Synovial Membrane
l
Synovial septa not absorbed in
adulthood have capacity to
develop into symptomatic and
inflammed tissue called plica
6
Knee Bursae
Knee Bursae
Fills intertissue junctions to prevent friction
and degeneration can be source of irritation
l
Suprapatellar (prepatellar)
–
–
l
Subpopliteal
–
l
Post-scope swelling in
suprapatellar bursa
Knee Bursae contl
Prepatellar
–
l
between popliteus and lateral femoral condyle that is compressed in
extension
Gastrocnemius
–
between medial head and medial femoral condyle that is compressed in
extension
Fat Pad
l
l
Infrapatellar
–
l
between skin and anterior
patella
between quad tendon and anterior femur that is compressed in flexion
Holds a lot of fluid post surgically
between skin and patellar
tendon
Fills interosseous voids
Highly innervated by type IV
articular mechanoreceptors
(nociocepters)
Deep Infrapatellar
–
between patellar ligament and tibial
tuberosity
Knee Alignment
Weight Bearing Mechanical Axis
l
From femoral to talar head
–
Bilateral stance – equal medial/lateral weight
bearing forces with no shear forces
–
Unilateral stance – shear forces
created secondary to dyanmic
influences
7
Genu Varum – “bow legged”
l
Genu Valgum – “knock knees”
Medial tibiofemoral angle > 180˚
l
Increased tensile forces laterally
Increased compressive forces medially
–
–
Medial tibiofemoral angle < 165˚
–
–
Increased compressive forces laterally
Increased tensile forces medially
Left Knee
Med
170-75º
Varum
vs.
Valgus
Left Knee
Lat
170-75º
Med
Lat
Knee Joint Frontal Plane Structure
l
Genu Varum/Valgus: 10° valgus
Genu Varum
Genu Valgus
increased load in
increased load in
medial compartment lateral compartment
Tibiofemoral Q Angle
l
Quadricep Vector
–
l
l
l
ASIS-Patella-Tibial Tubercle
Males (15˚) vs. Females (20˚)
Structural
Functional (dynamic)
Knee Joint Sagittal Plane Structure
Genu Recurvatum
> 5-10° hyperextension
8
Knee Biomechanics
Tibiofemoral Convex-Concave Morphology
Knee Sagittal Plane Motion
Knee Joint Accessory Motions
NWB Movement
Tibial Movement
Flexion
Extension
WB Movement
Femoral Movement
posterior glide
anterior glide
anterior glide
posterior glide
based on convex-concave rules without regard to
capsuloligamentous influence
Combined Rolling and Gliding
combined rolling and gliding
l
femur does pure posterior roll for first
15-20°
l
combined posterior roll and anterior
glide through midrange
l
flexion ROM ends with pure gliding
Screw Home Mechanism
Arthrokinematics
l
Due to the difference in the size of the condyles
and plateaus (the screw home mechanism) allows
the knee to lock in full extension which requires
about 10˚ of external rotation at terminal
extension
l
Obligate conjoint rotation occurs with sagittal
plane motion
9
Knee Transverse Plane Motion
Screw Home Mechanism
NWB Movement
Tibial Movement
Knee Transverse Plane Motion
Screw Home Mechanism
WB Movement
Femoral Movement
Terminal Extension
tibial ER
femoral IR
Knee Unlocking
tibial IR
femoral ER
Knee Axes and Motion
Functional Motion of the Knee
The three axes of the knee. Around each axis is a rotation and along each
axis is a translation to create a total of six degrees of freedom
Lower Extremity Pronation
Knee Flexion, Valgus, and Tibial Int Rotation
Lower Extremity Supination
Knee Extension, Varus, and Tibial Ext Rotation
Right Hand Rule
Knee Motion and Axes
conjoint rotation
Interaction of Rotations and Translations
AXIS
ROTATION
Anterior-Posterior Ab-Adduction
Medial-Lateral
Flex-Extension
Proximal-Distal
Int-External
DISPLACEMENT
Anterior-Posterior
Medial-Lateral
Approximation-Distraction
AXIS
X
Y
Z
The three axes of the knee create 3 rotations and 3 translations. Around
each axis is a rotation and along each axis is a translation to create a
total of six degrees of freedom
10
Knee Joint Range of Motion
Knee Rotation Range of Motion
Knee Flexion
At 0° of flexion:
no frontal or transverse plane motion
At 30° of flexion:
mild frontal plane motion
At 90° of flexion:
maximal transverse plane motion
AROM with hip extended
AROM with hip flexed
PROM
120°
140°
160°
Knee Extension
A/PROM
5 to 10 ° hyperextension
Knee Rotation
ER in full extension
ER in 90 degrees flexion
IR in 90 degrees flexion
5°
45°
30°
Knee Range of Motion
necessary for Gait and ADLs
Knee Rotation
l
Longitudinal axis near the medial tibial
intercondylar tubercle with maximum
of about 90° of motion
–
l
NWB IR – lateral tibial condyle
moves anteriorly
–
NWB ER – lateral tibial condyle
moves posterior
–
Reverse in WBing at femur
Rotation is blocked by passive ligament
tension and increased bony congruency
Stance Phase of Gait:
20° flexion
Swing Phase of Gait:
65° flexion
Stair Climbing:
80-90° flexion
Sit to Stand:
80-90° flexion
Ride Bike
105-110° flexion
Lift Object from Floor
115-120° flexion
Joint Capsule
Knee Joint
Resting Position
l
Envelop of tissue that surrounds and
encloses the tibiofemoral and
patellofemoral joints
l
Large and completely attached
l
Lax in resting position (full extension) with
several recesses
l
Stability is provided through passive
ligamentous and dynamic musuclar
structures
25° flexion
Closed Pack Position
full extension
11
Knee Stability
l
l
l
Anterior Support
– Patellar retinaculum and the quadriceps
– ACL
Lateral Support
– patellar retinaculum, ITB, biceps femoris, popliteus, and lateral
gastroc head
– LCL
Medial Support
– patellar retinauculum, semimembraneous, and pes anserine
muscles
– MCL
Posterior Knee Stability
l
–
l
Originates from TFL anteriorly and gluteus
maximus posteriorly to extend down
lateral aspect of thigh and insert on
Gerdy’s tubercle on the proximal tibia
n
Slip to patella (iliopatellar ligament) from
lateral side so that as the ITB moves posterior it pulls on the lateral side of the
patella causing it to tilt laterally as knee
flexion increases
n
Also can externally rotate the tibia
semimembraneous to the lateral femoral
condyle which is taut in extension
Arcuate popliteal ligament
–
From fibula to the posterior intercondylar area
of the tibia and fabella
l
Fabella – sesamoid bone imbedded with
the lateral head of the gastroc
l
Popliteus, hamstrings and gastroc also provide
support and limit hyperextension
l
PCL
fabella
Iliotibial Band
Iliotibial Band
n
Oblique popliteal ligament
Can act as both a flexor and
extensor of the knee
–
Vector is anterior to F-E axis
in extension but posterior to
the F-E axis after the knee
flexes about 30˚
caused by an intact
ITB in absence of
the ACL
Pivot Shift Phenomenon
IT band orientation relative to flexion-extension axis
Patient Complaint:
l
description of “giving way” or “slipping” sensation that occurs with cutting
or deceleration activities
Clinical Phenomena:
l
l
anterior subluxation of the lateral tibial
plateau when the knee approaches full
extension, followed by a sudden reduction
of the tibia as the knee approaches 30-40˚
of flexion
“thud”, “jerk”, or “slip” - this sensation
typically reproduces the patient’s
complaint of instability
12
Knee Ligaments
Function
– provide joint stability and prevent excessive motion
– guide motion
ACL: check anterior tibial shear/IR
87% of anterior restraint
PCL: check posterior tibial shear
94% of posterior restraint
MCL: check tibial abduction/ER
LCL: check tibial adduction/IR
Anterior Cruciate Ligament Anatomy
l
l
Originates well posterior in the notch on posteromedial surface of
lateral femoral condyle
Inserts into fossa anterior and lateral to anteromedial tibial spine
l
ACL is a composite of individual fascicles
collectively function so that a portion
taut throughout the ROM
l
The ACL is isometric (physiometric)
–
l
that
of the ACL is
normal ACL undergoes less than 2.5 mm
length change over full ROM
Hamstrings are the dynamic synergist
ACL Function
• Primary restraint to anterior translation of tibia on femur
• Provides 86% of the resistance to anterior tibial translation
• Resists hyperextension and
internal rotation of the knee
• Secondary stabilization to
varus and valgus stress
ACL Origin-Insertion:
l
l
A normal lateral spiral twist to ACL fibers allows a portion
of ACL to be taut at all times
– Anteromedial bundle
• taut in extension
– Posterolateral bundle
• taut in flexion
Laxity profile
– generally tighter in last 30°
of extension
Anteromedial bundle taut in extension
Postero- lateral bundle taut in flexion
13
Posterior Cruciate Ligament
Torn PCL on MRI
Intact PCL
Torn PCL
Posterior Cruciate Ligament
l
l
l
l
Vertically oriented
Prevents 94% of posterior translation of
tibia on femur
Prevents hyperextension
Anterolateral and posteromedial
bundles
1.5x larger
than ACL
ACL vs. PCL
ACL vs. PCL
ACL
l
Often the “primary lesion”
l
Rotational (coupled) as well as
an anterior instability
–
–
l
ACL
Frequently one of several ligamentous structures involved
l
Straight posterior instability
• Loaded in Flexion
– Posterior muscles in last
30° are important
• Joint Changes
– Rapid deterioration;
menisci at risk
l
Primary Complaint
– anterior knee pain
isolated injury
Pivot shift problem
Primary Complaint
–
PCL
l
“giving way” and instability
PCL
• Loaded during extension
– Quads are the key
• Joint Changes
– Slow deterioration with
OA changes at MFC and
pf joint
• Usually a non-contact injury • Usually a contact injury
14
Posterolateral Corner
Arcuate Complex
ACL vs. PCL
Operative treatment to
allow athletic function
• Instability and uncontrolled
forces yield poor functional
outcomes
• Young, non-contact injury
generally needs
reconstruction
Non-operative treatment
can allow athletic function
LCL
• Good muscular function yields
good functional result
• Surgical necessity dictated by
severity of injury
Arcuate
Ligament
– Isolated PCLs – conservative
– Combined injuries – surgery
Popliteus
Tendon
• Consider pre-disposing factors • Needs to be a substantial graft as
PCL is 2x as strong
Posterolateral Corner
Medial (Tibial) Collateral Ligament
Superficial to Arcuate Complex
l
ITB
Lateral
Gastroc
Head
l
l
Biceps
Femoris
Runs from medial femoral condyle down to the
medial proximal tibia
– Deep and superficial layers
Taut in extension/loosens in flexion
– “safe range” from about 90-20°
Resists tibial abduction (valgus stress) and ER
when knee is flexed
– Posterior oblique ligament critical to prevent
anteromedial rotary instability
Valgus Restraints
Lateral (Fibular) Collateral Ligament
At 30° of flexion
l
Runs from the lateral femoral condyle
down to the posterior aspect of the
fibular head
In full extension
MCL
78%
MCL
57%
l
Taut in extension
ACL-PCL
Capsule
13%
7%
ACL-PCL
Post/Med Capsule
Ant/Med Capsule
15%
17%
8%
l
Resists tibial adduction (varus stress)
and IR when knee is flexed
15
Varus Restraints
Rotary Instabilities of the Knee
At 30° of flexion
At full extension
LCL
69%
LCL
55%
ACL-PCL
ITB-Popliteus
Post Capsule
Ant/Med Capsule
12%
10%
5%
4%
ACL-PCL
ITB-Popliteus
Post Capsule
Ant/Med Capsule
22%
5%
13%
4%
Anteromedial
Instability
Anterolateral
Instability
Meniscal Anatomy
Semilunar wedges
of fibrocartilage
interposed between
the femoral condyles
and tibial plateau
Posteromedial
Instability
Posterolateral
Instability
Lateral Meniscus
Medial Meniscus
l
l
l
"C" shaped
Broader posteriorly than anteriorly
Peripheral Attachments:
•
•
•
•
entire peripheral border is firmly
attached to the medial capsule
semimembranosus tendon slip
attaches to posterior horn
fibers of ACL attach to anterior horn
meniscopatellar fibers attach to
medial border of meniscus
l
Left Knee
l
l
l
"O" shaped covering 2/3 of tibial plateau
Smaller in diameter, thicker in periphery, and wider in body
than the medial meniscus
More mobile than medial meniscus
Left Knee
Peripheral Attachments:
•
•
•
popliteus muscle (not tendon) sends
fibrous slip to posterior border
ligament of Wrisberg (meniscofemoral ligament attaches to
posterior horn
anterior horn to ACL
16
Chock Block Shape
l
Meniscal Vascularity
Frontal and sagittal x-sections show the
triangular wedge shape (thick on periphery and
Blood supply comes
from the genicular
arteries with vascular
penetration to the
peripheral 10-30%
thin centrally)
Meniscal Vascularity
Meniscal Function
Vascular Zones
Joint Stability
•
•
Red Zone - peripheral capsular attachment area; outer 3 mm rim
Pink Zone - junction of vascular and avascular zone; blood supply
on periphery, but not centrally
•
White Zone
Avascular Zone
•
l
Small but significant role in resisting varus, valgus, rotational, and
AP stresses
l
If ACL intact, menisectomy does not
significantly increase AP laxity
l
If ACL deficient, menisci play a
important role in stability
inner 2/3 of meniscus
without blood supply
Shock Absorption and Load Transmission
Menisci é the tibiofemoral contact area by 75%
• Loss of menisci results in smaller areas of
tibiofemoral contact
• Partial menisectomies é peak local contact
stress by 65%; total menisectomy by 235%
l
Menisci transfer centrally applied stresses
•
Loss of menisci function through menisectomy
radial tear will result in increased load transfer
articular cartilage and subchondral bone
After menisectomy there is a significant
(3 mm) in AP laxity
–
Removal of posterior horn of medial
meniscus alone will destabilize the meniscus
mobility
increase
Meniscal Function
Meniscal Function
l
–
more
Architectural
Architectural
stability
l
Nutrition and Joint Lubrication
Ø
l
radially
or
to
The menisci help distribute
a thin film of synovial fluid
over the surface of the
articular cartilage
Joint Congruency
Ø
Tapered ring geometry
promotes the mating of
two incongruent surfaces
17
Meniscal Movement
Meniscal Passive Biomechanics
Flexion
Femoral condyles displace menisci as a result of compression and
translation
• menisci move posterior with flexion and anterior with extension
• the conjoint internal rotation of the tibia during flexion occurs about
an axis medial to the knee joint
• medial meniscus moves about 6 mm and the lateral meniscus about
12 mm
menisci move posteriorly
l
Extension
menisci move anteriorly
l
lateral meniscus moves approx. twice as much as medial
Meniscal Passive Biomechanics
Flexion
l
l
Extension
Medial Meniscus - posterior glide is
assisted by semimembranosus and
counteracted by the pull of the
meniscopatellar fibers and the ACL
which attach to the anterior horn
l
l
Lateral Meniscus - posterior glide is
assisted by the fibers of the popliteus
Tibial Rotation
l
POP
Medial Meniscus -assisted by meniscopatellar
fibers and influenced by the active contraction
of the quads
Lateral Meniscus - posterior horn is pulled
anteriorly by the increased tension on the
meniscofemoral ligaments from the PCL
influenced by meniscopatellar fiber tension
and the larger articulating femoral condyle
patellofemoral joint functional anatomy
§ the patella is a sesamoid bone imbedded
within the quadricep muscle tendon
§ patella tracks cephalically on extension
and caudally with flexion of the knee
§ tracking course is dictated by passive and
active restraints or stabilizers
SMB
Patellofemoral Joint
Functions of the Patella
l Protection and Cosmesis
l Acts as an anatomical pulley to
increase quadricep efficiency by
30%
Ficat, 1977, Frankel, 1980
l Transmits quadricep force to the
tibia
“I’ve had it, Doc! … I’ve come all the way from
Alabama with this danged thing on my knee!”
18
patella is the center of the stabilizing forces
Passive Static Stabilizers
• joint capsule
• patellofemoral ligaments
• medial & lateral retinaculum
• medial retinaculum originates from the medial border
of the VM, quadricep tendon, and patellar border
• lateral retinaculum runs between the distal portion of
the ITB and the lateral edge of the patella and
extensor mechanism
dynamic stabilizers of the patella
Quadriceps
– the muscular forces of the VM and VL control
patellar movement in 0-20°
• vastus lateralis, intermedius, & medialis
• rectus femoris
• vastus medialis oblique fibers
Articularis Genu
– suprapatellar muscle which retracts the
suprapatellar bursa on knee ext
Biceps Femoris & Pes Anserine
– control tibial rotation
oblique portion of vastus medialis
structural restraints-determinants
• the oblique fibers of the VM insert at a 55°
angle to the long axis of the femur
• lateral femoral condyle is a
buttress against lateral
dislocation
Lieb and Perry, 1968
• prime function is patellar stabilization and
tracking
• depth of PF groove
• their fibers are not really in a position to
act as a synergist to knee extension
• Q angle
Q Angle
Q Angle
l
Vector representing the angle of lateral pull on
the patella by the quadriceps
–
–
–
Proximal arm pointing at ASIS
Axis of rotation in center of
patella
Distal arm bisects the tibial
tuberosity
l
l
less than 15° in men and 20° in women is desirable?
average of 14° in men
and 17° in women
Insall, 1971
l
Q angle measure using ASIS as a
proximal landmark underestimates
the Q angle by approx. 4° or the
lateral force on the patella by approx.
20%
Schulties, et al, PT, 1995
19
static Q angle assessment
Patellar Articular Cartilage
static measurement of Q angle in full
extension may NOT be a reliable
indicator of malalignment for 3 reasons:
•
weakness of the medial quadriceps will not
allow pull of quads to be in line with the
rectus femoris as is measured (creating an
increased "functional" Q angle)
•
influence of tibial torsion (minimance or excess) in
functional activities such as gait
•
increased pronation of the lower extremity secondary
to decreased proximal strength in gluteals and hip
rotators
articular surface
l
normal patellar articular cartilage is
like a teflon coated sponge
l
it’s 8 times as slick as two ice two
cubes moving across one another
l
functions to disperse stress of contact over a large surface
area and prevent stress concentrations which can occur with
bone to bone contact
l
motion is necessary to keep articular cartilage healthy
Patellofemoral Articulation
l
Reasonably incongruent joint
–
–
articular contact pressure
patellar motion follows a concave lateral curve
–
Maximum congruency contact
area of articular surface is only
about 30%
Patella resides superior to the
intercondylar groove against
the suprapaterllar fat pad
Maximal medial/lateral glide in
full extension
articular contact pressure
if the patella centralizes earlier, both patellar facets stay in contact with the femur throughout the entire range. Johnson, 1985.
0-10°
30-90°
the patellar tendon contacts the
femur and the patella contacts the
supratrochlear fat pad
patella centralizes in the sulcus and tracks
between the trochlear facets. Contact area is
now moving proximally and enlarges with
increasing flexion
20°
the lateral facet of the patella
comes into initial contact with the
lateral ridge of the femoral sulcus
90°+
the patella contacts only the medial femoral facet
135°
the odd facet of the patella comes in contact
with the medial femoral condyle.
.
20
Patellofemoral Joint Stability
PFJ closed pack and resting positions
l
l
l
Resting – Full extension
Closed Pack – mid flexion
–
l
Unstable in full knee extension
Dislocation requires rupture of medial patellofemoral ligament
60-90 degrees where surface
contact is maximized
patellofemoral joint reaction force (PFJRF)
force equal and opposite to
the resultant forces of the
quadricep tension and the
patellar tendon tension
PFJRF
Pressure = Force (BW)/Area
LE limb malalignment
Abnormal Patellar position
The quadricep tension force
increases sharply after 15° of
flexion in closed chain function:
30° of flexion
Walking
Stair Walking
60° flexion
Deep Squat
Walking - 1 x BW
Stairs
- 3 x BW
Squats - 5 x BW
- 1 x BW
- 1.5 x BW
- 3.3 x BW
- 4 x BW
- 8 x BW
patellofemoral joint reaction force – stress
contact area influenced by
l
PFJRF rises sharply after 30°
of knee flexion. The literature
has suggested the following:
In closed chain knee flexion the body weight shifts behind the knee with flexion
and the moment arm increases from the knee to the body weight line as
further flexion occurs. The quads must provide greater force to prevent the
knee from collapsing, and this ultimately loads the pf joint
Stress = PFJRF/area applied
l
Patellofemoral Joint Reaction Force affected by
Steinkamp, AJSM, 1992
decreased
contact area
PFJR Stress
PFJ PFJForce
Force
Pain
PFJ Stress
PFJ
Stress
1200
30
1000
25
800
20
600
15
400
10
5
200
zone of safety
0
Increased
PFJR force
0
0
0
30
Leg
Press
60
90
Knee Ext
30
Leg Press
Leg Press
60
90
Knee Ext Knee Ext
Leg Press
Knee Ext
Patellofemoral
Protection: OKC 90-45° CKC 45-0°
21
minimizing compression pressure
A load bearing joint may minimize
compression stress by
STRESS = force/area
• maximizing the surface area of
contact
• possessing subchondral bone with
a well organized trabecular
structure
NWB
vs.
Patellofemoral Stress vs. Force Analogy
large surface area creates
less stress on the snow
WB
patella tilts on fixed femur vs. femur rotating on fixed patella
chondromalacia
• actual erosion of the patellar articular
cartilage
• the gross AC changes of CM are not
necessarily always the cause of the
clinical syndrome of PF pain
Both resulting in increased contact pressure on the lateral facet
• this term is reserved for the gross
pathological entity of the softening of
the AC, fibrillation, ulceration, and
eventual erosion of bare bone
Powers CM, et al. J Orthop Sports Phys Ther. 2003
chondromalacia
Chondromalacia Progression
Graded by Outerbridge, JBJS, 1961
I
swelling/softening of AC
II
fissuring and fragmentation
(crab meat appearance)
III enlargement of crab meat area
swelling and
softening
fissuring and
fragmentation
crab meat
enlargement
ulceration to
subchondral bone
IV ulceration and loss of cartilage with
exposure to bare bone
22
Kellgren-Lawrence Grading Scale
l
Based on 4 features
– joint space narrowing
– osteophytes
– subchondral sclerosis
– subchondral cysts
Kellgren-Lawrence Grading Scale
Grade I
– Doubtful narrowing of joint space and possible osteophytic lipping
Grade II
– Definite osteophytes and narrowing of joint space
l
l
l
Grade III
– Moderate multiple osteophytes, definite
narrowing of joint space, some sclerosis,
and possible deformity of bone contour
l
Grade IV
– Large osteophytes, marked narrowing of
joint space, sever sclerosis, and definite
deformity of bone contour
Muscle – Tendon Axis Orientation
Quadriceps
ITB
EXTENSION
Sartorius
IR
ER
Gracilis
Biceps
Femoris
Semimebranosus
Semitendinosus
Quadriceps
l
l
Vasti and Rectus Femoris (biarticular)
Mechanical efficiency increased via patella to
increase the moment arm for torque production
–
l
l
–
–
–
Lateral
Gastroc
Anterior shear offset by ACL in open chain
–
–
Patellectomy decreases torque output by 30-50%
Isometric stabilization
Concentric knee extension
Eccentric damping (in gait)
Deceleration or control of weight bearing knee flexion
Medial
Gastroc
Quadriceps
Function
–
FLEXION
–
l
Anterior shear from 70 – 0˚
Neutral shear at about 70˚
Posterior shear 90 – 70˚
Minimal anterior shear in
weight bearing (mostly
shear on PCL)
23
Weight Bearing Demand on Quads
l
No knee extensor activity needed in full erect
posture as line of gravity is anterior to knee axis
and the resultant gravitational torque created
maintains knee extension –putting stress on
posterior structures
Increasing demand on Quads as moment arm
moves from perpendicular to parallel to gravity
Weight Bearing Demand on Quads
Increasing quad
demand as moment
arm lengthens and
squat depth increases
l
Quadricep External Torque Production
Open chain vs. closed chain quadricep demand
l
Shaded red area >
70% torque
demand on quads
Non-Weight Bearing Demand on Quads
Active – Passive Insufficiency
l
45- 90°in CKC
45-0°in OKC
Active – Passive Insufficiency
Passive Insufficiency
Muscle Insufficiency
–
Relative
external torque
(% max)
limited ability of a two joint muscle to produce force (active
maximal measurable tension) when joint position places the
muscle on stretch or it has maximally shortened at its end range
•
Biarticular antagonist maximal elongation prohibits
agonist from further passive movement at a joint
PASSIVE
ACTIVE
INSUFFICENCY
INSUFFICENCY
Hamstrings actively insufficient
Rectus Femoris passively insufficient
Rectus Femoris actively insufficient
Hamstrings passively insufficent
24
Active Insufficiency Example
l
Hip flexion with knee extension – rectus
is actively overshortened and hamstrings
are passively stretched
l
The rectus femoris is a weaker hip flexor
when the knee is extended because it is
already shortened and thus suffers from
active insufficiency
l
Similarly, the rectus femoris is not
dominant in knee extension when the
hip is flexed since it is already shortened
Quadriceps Extension Lag
l
l
Inability to complete active range of motion in spite of full
available passive range
"Lag" usually connotes pathology or weakness
– Adhesions preventing contractile
structure excursion
l
–
l
l
Hip extension with knee flexion – hamstrings are actively
overshortened and rectus is passively stretched
l
The hamstrings are a weaker knee flexor when the hip is
extended because it is already shortened and thus suffers
from active insufficiency
l
Similarly, the hamstrings are not
dominant in knee flexion when the
hip is extended since it is
already shortened
Hamstrings
l
Extend the hip, flex the knee, and rotate the leg
l
Length-tension relationship important
–
can't extend knee when
patellofemoral joint is adherent
Pathological weakness of
contractile structure
Hamstring Exercise
l
Active Insufficiency: Another Example
What’s wrong with the positioning
for this hamstring exercise?
What is it an example of?
What muscle would lower the
trunk to the floor
Most effective when lengthened over the
flexed hip
l
Actively insufficient in prone with hip extended
l
Passively insufficient with hip flexed
–
Semimembraneous retracts medial meniscus
with knee flexion
–
Pes Anseriine ST, gracilis, sartorius help
stabilize the medial knee
posterior view
lateral view
Popliteus
l
Popliteus “unlocks” the knee by internally rotating the
tibia on the femur (OKC) or externally rotating femur
on the tibia (CKC) to initiate knee flexion.
l
important posterolateral stabilizer of
the knee
l
stabilizes the lateral meniscus during
extension to flexion maneuvers
25
Knee Strength Testing
l
Isokinetic Torque/Testing
QUADS
Torque Production as
measured by a dynamometer
Speed
Males Peak Torque
Females Peak Torque
H/Q Peak Torque Ratios
60°/sec
100% of BW
90% of BW
60%
180°/sec
70% of BW
60% of BW
75%
300°/sec
50% of BW
40% of BW
85%
450°/sec
35% of BW
25% of BW
95%
60°/sec
60% of BW
54% of BW
180°/sec
53% of BW
45% of BW
Decrease PT/BW goals by 10%
for each decade over 40
300°/sec
43% of BW
34% of BW
450°/sec
33% of BW
24% of BW
HAMS
No significant difference
between dominant and nondominant sides
Concentric vs. Eccentric Torque Production
ü
The higher the speed of eccentric contraction
the greater the torque production
Quads
ü The higher the speed of concentric contraction
Peak Torque
the lower the torque production
Hams
-120
-60
Eccentric
0
Knee
60
120
180
240
Angular Velocity (˚/sec)
Finally, examples of how
the joints of the lower
quarter work in concert
300
Concentric
poor proximal hip control allows
Hip-Knee Synergistic Relations
l
Hip and knee work synergistically
–
–
Hip/knee extension propels the body upward
or forward
Hip/knee flexion advances
or swings the lower limb
“Medial Collapse”
l
Femoral IR and adduction
allowing increased knee valgus
and Q angle
l
Work the gluteus maximus to
control the rotation and
gluteus medius to control the
adduction
26
Finally, one last example …
Thank You
Tight gastroc è compensatory STJ pronation è
abnormal transverse plane rotation at tibia and
femur è alteration of Q angle and patellar
tracking è patellofemoral pain
27
Medical Exercise Techniques:
Rationale and Ideas for Therapeutic
Exercise in Rehabilitation
Ross Querry, PT, PhD
Associate Professor
Department of Physical Therapy
Lecture Objectives
If exercise therapy
could be packed into
a pill it would be the
single most widely
prescribed and
beneficial medicine
the world has ever
known
Exercise Physiology Review
Review important elements of exercise
physiology that impact exercise prescription
Discuss the background elements of a patient
that are brought forward for exercise
consideration
Present concepts and ideas that contribute to
diversity in exercise selection and application
Regional Interdependence
in a Different Way
Muscle Physiology
Energy Production
The Real Deal – Amazing Structure
Ventilation
Circulation
Metabolism
Motor Unit:
The Real Deal 2
The Nerve-Muscle Functional Unit
Organized
Each muscle has at least one
motor nerve that may contain
hundreds of motor neuron
axons. Axons branch into
terminals, each forming a
neuromuscular junction with a
single muscle fiber
Hypertrophy
Motor Unit
The Real Deal
Force Regulation in Muscle
Physical Properties of Motor Units
Types and number of motor units recruited
– More motor units = greater force
– Fast motor units = greater force
Initial muscle length
– “Ideal” length for force generation
Nature of the motor units neural stimulation
– Frequency of stimulation
– Simple twitch, summation, and tetanus
Energy production/ bi-products
Motor Unit
Recruitment Patterns
NMES
Belgium Blue Bull
Exercise warm-up: Blood flow
Sources of ATP for Muscle
Contraction
Circulation distribution impacts metabolic substrates
ATP – Adenosine Triphosphate
ATP-PC System: Fast but limited
Sources of Fatigue
Creatine Phosphate Recovery
Related to METABOLIC
demand not effort
1.5-2 minutes for full
recovery
Fast lactic acid system
similar in timing
How would you know if you
didn’t wait long enough?
Blood Glucose
Glycogen
Blood Glucose
Gylcolosis
More complex quick
Still fairly rapid
Metabolic bi-product
has direct impact on
performance
Chemical fatigue vs
central fatigue
Lactic acid build up
blocks pathway
Recovery restores
substrates
All recovery is aerobic
Lactate
Consider
–
–
–
–
Effort of work vs
Metabolic demand
Cause of fatigue
Goal of exercise
Use as an intensity
factor
Breakdown of glycogen or glucose to produce ATP
CHO → 2 ATP + Lactic Acid + Heat
Carbohydrate (CHO) stored in muscle as glycogen
–
–
–
Set to set result
changes
Aerobic Glycolysis
3 – 5 minutes into Continuous Activity
Lactate
Anaerobic Glycolysis
30 Sec. to 4 Min.
Rest periods
Glycogen
Gylcolosis
CHO + O2 → ≈ 36 ATP + CO2 + Water + Heat
Pyruvate as a result of glycogen anaerobic glycolysis
Occurs at 3-5 minutes into continuous activity
Production rate and quantity dependent on O2
availability, aerobic muscular conditioning, biochemical
enzymes.
300-400 g in body’s total muscle (1200-1600 kcal)
70-100 g in liver (280-400 kcal)
Storage quantity influenced by
Training
Diet
Aerobic Free Fatty Acid
12-15 minutes into Continuous Activity
FFA + O2 → ≈ 100 ATP + CO2 + Water + Heat
Begins contributor 12-15 minutes into activity
Production rate and quantity dependent on
–
–
Intensity and rate of exercise
Muscular aerobic training adaptations
Enzyme quantity increase
Mitochondria population increase
O2 processing increase
Hemoglobin population increase
Kreb cycle/ TCA cycle/
Aerobic…All fuel is welcome
Protein
Carbohydrate
Fats
Interdependence of Energy Systems
O2
Aerobic training effect
(Biochemistry - USTA)
O2 Deficit/Debt
How often do we see
this in the clinic?
How do you adjust?
Differences between aerobic and
production
Biochemical
PathwaysATP
anaerobic
short term
long term
immediate
http://www.expasy.ch/cgi-bin/show_thumbnails.pl
Exercise Application
Techniques
Exercise Application
Exercise should be as precisely prescribed as
medicine for it to realize its intended and
maximal benefit
Why is this Important?
Most common
intervention provided
–
–
12 patients/day doing
6 exercises = 360
exercises/week
How much thought
goes into the plan
“Exercise is as much a medical
pill as a beta-blocker is to a heart
patient”
“If you lose weight, you’ll have more energy.
Why do you think they call it FATigue?”
WHO IS YOUR PATIENT?
Constanza vs. Kournikova
Where do you start?
Establish a baseline
–
–
–
–
–
Genetics
Age
Size
Sex
Attitude
Functional Tests
Pain levels
Postural Assessment
MMT
Rating of Perceived Exertion
WHAT IS THE TARGET TISSUE?
WHAT IS THE EXERCISE GOAL?
Increase capsular mobility
Increase muscular flexibility
Improve balance
Enhance motor function or
neuromuscular control
Increase muscle performance
–
Strength, power, endurance
Improve cardiovascular endurance
Challenge the anaerobic or aerobic
system
SAID Principle
Specific Adaptations to Imposed Demands
Tissues remodel
according to stimulus
imposed on them
Rehab activities should
be chosen based on the
desired outcome
What is the best way to
get better at swimming?
We’ve heard it, said it,
but how do we apply it?
Science of Specificity
Specific motion of a specific joint through a specific range at a specific speed in a specific
direction through specific input of specific stimuli to obtain a specific muscle response
or specific facilitation of a specific tissue dependent upon the specific tissue involved in
a specific injury to achieve specific physical performance requirements and goals with
specific fiber muscle recruitment fueled by a specific muscle energy system .
Science of Specificity
Specific motion of a specific joint through a specific range at
a specific speed in a specific direction
through specific input of specific stimuli
to obtain a specific muscle response or
specific facilitation of a specific tissue
dependent upon the specific tissue
involved in a specific injury to achieve
specific physical performance
requirements and goals with specific
fiber muscle recruitment fueled by a specific muscle energy
system.
What is the tolerance of the Target
Tissue? Dependent upon:
Type of tissue
–
–
Remember, whether or not we actually think
About each component in our exercise choice
And prescription, each component is still present
And has its specified impact on the physiological
System.
Phase of healing
Irritability
General health
–
–
WHAT DOES THE TARGET
TISSUE NEED?
Contractile vs. non-contractile
Vascularity
Alcohol, smoking, diabetes,
nutrition
infection
TISSUE PROTECTION
Contractile
–
–
Avoid passive insufficiency
Avoid eccentric
Non-Contractile
Poor Vascularity
–
–
Limited or partial arc
Prolonged immobilization
Optimal Stimulation for Tissue Regeneration
TISSUE STIMULATION
Gentle mechanical stress with absence of pain as
guideline for intensity of stress causing collagen
to be laid down along the lines of stress
Bone biomechanical energy in the line of stress
Cartilage intermittent compression-distraction or
gliding
Collagen modified (painless) tension along the line
of stress
TISSUE CHALLENGE
Challenge the tolerance to
shear, compression, and
tension
Wolfe’s Law
–
– Pain is guideline to avoid deformation of
tissue detrimentally
How do I sequence my exercise
rehabilitation?
REHABILITATION PHASES
MOBILITY
STABILITY
CONTROLLED MOBILITY
SKILL
What ROM is appropriate?
Limited
partial
full arc
Uni
multi-planar
Biomechanically correct
Graded specific exercise with an overload stimulus
creates adaptive changes in the internal architecture
of the tissue and aligns fibers in their orientation of
mechanical stress without adhesion development
ability to move through a range of motion
balance, coordination, motion control
proximal stability with distal mobility
high speed, functional, ballistic movement
What type of contraction?
Isometric
Isotonic
–
–
Concentric vs. eccentric
How is the overload different?
Isokinetic
Do you change exercises
because you are bored with
them or because of a rationale
based decision?
How many ways could you
increase the intensity of an
exercise without increasing the
weight
How about the speed of motion?
Slow
Fast (tempo, pause at top/bottom)
Pace
Non-Functional
Activity Simulation
What exercise equipment is
available? Advantages/disadvantages
What position or posture?
Supine
Prone
Sidelying
Sitting
Kneeling
Standing
Weight Bearing
(CKC)
Non-Weight
Bearing (OKC)
Joint compression
forces vs Long axis
distraction forces
Dumbbells
Tubing
Machines
Ergometer
Functional Devices
Home vs. Clinical
Open vs. Closed Kinetic Chain
Exercise
Simple definition for
rehabilitation:
–
Open
–
Closed
Distal end segment is free
Distal end segment is fixed
to an object (which may or
may not be moving)
What would happen if we corrected all posture deficits?
CLOSED KINETIC CHAIN EXERCISE
Distal stabilization with proximal motion
utilizing body weight as resistance
Overload
–
–
low resistance
high acceleration
larger resistance
slower acceleration
immovable resistance
deceleration emphasis
Definition
–
EXERCISE CHAIN CONTINUUM
Intrinsic – the weight of the body
Extrinsic – weight outside the body
Reps
–
Performed until onset of substitution (as
opposed to failure) at the weakest link of
the kinetic chain
OPEN KINETIC
CHAIN
CLOSED KINETIC
CHAIN
movable boundary
no load
movable boundary
external load
fixed boundary
external load
“ shot put”
“bench press”
“push up”
OPEN CHAIN RESISTIVE EXERCISE PROGRESSION
CONTINUUM
closed kinetic chain
exercise and evaluation
Active assistive/Eccentrics/PNF/Manual Resistance
closely monitor for the weak link patients are expert at masking and
substituting for the weak link
Multi angle
Multi angle
submaximal intensity
maximal intensity
isometrics
isometrics
Short arc
Short arc
Short arc
submaximal intensity
isokinetics
isotonics
isokinetics
Full arc
Full arc
Full arc
submaximal intensity
maximal intensity
maximal intensity
isokinetics
isotonics
isokinetics
Eccentrics
CKC Resistive Exercise Progression
Continuum
POSITION
ROM
CONTRACTION
CLOSED CHAIN RESISTIVE EXERCISE PROGRESSION
CONTINUUM
UE EXAMPLE
Gravity Eliminated
Gravity Eliminated
Short Arc
Full Arc
Isotonics
Isotonics
short arc wall push up
full arc wall push up
Gravity eliminated short arc
Gravity eliminated full arc
isotonics
isotonics
Shuttle - Leg Press
Shuttle - Leg Press
Partial AntiAnti-Gravity
Partial AntiAnti-Gravity
Short Arc
Full Arc
Isotonics
Isotonics
45°
45° angle SA incline push up
45°
45° angle FA incline push up
Anti gravity
Anti gravity
multi angle
isometrics
stabilization
Wall Sits
Tubing DumbbellsImpulse-BAPS
AntiAnti-Gravity
MultiMulti-angle
Anti gravity
protected arc isotonics con/ecc
Anti gravity
full arc
AntiAnti-Gravity
AntiAnti-Gravity
AntiAnti-Gravity
Isometrics quadruped holds push up
position holds
MultiStabilization balance or tilt board
Multi-angle
Protected Arc Isotonics
traditional push upsups-Con/Ecc
Con/Ecc
Full Arc
Isotonics
push up +; depth push ups
Functional Activities
AntiAnti-Gravity
wheelbarrow; treadmill;
slide board or profitter
Full Arc
PARAMETER
CKC EXERCISE
OKC EXERCISE
Definition
Axis of Motion
Stabilization
Movement
Emphasis
Planes
distal end segment fixed
motion distal and proximal
postural means
functional and coordinated
domination
triplanar
distal end segment free
motion only distal
artificial (straps)
isolation
isolation
cardinal plane emphasis
Muscle Contraction
accelerate/decelerate/stabilize
concentric or eccentric
Velocity
Resistance
variable acc/deceleration
body weight
Reactive
neuroproprioceptive
distal end segment fixed
variable or fixed
external loads
Proactive
Feedback
Joint Mobilization
Exercise Fatigue
Joint Stability
Exercise Variation
Functional activities
Treadmill- Bicycle
Plyometrics
Box Jumps
Plyometrics push up clappers; UE drops
open vs. closed kinetic chain contrast
Movement Purpose
Anti gravity
isotonics con/ecc
Squat-Lateral
Steps Ups
Stairmaster
detected by substitution
joint compression
unlimited potential
proximal segment is
fixed
momentary failure
long axis distraction
limited by machine
design
How do I provide resistive training
overload?
Intensity
–
–
–
–
–
–
concentric vs. eccentric; (speed specificity)
increasing weight or resistance (ex: DeLorme, DAPRE, Holten)
changing speed or rate of movement (time under tension), pause vs fluid at
endpoints of repitition
muscular isolation
Lever arm length
Pre fatigue, partial reps in different ranges, isotonic/isometric mix in set
Frequency
Duration
–
–
–
–
number of training sessions/unit of time
rest intervals (recovery time; challenge aerobic or anaerobic systems)
increased sets or repetitions
increased time of training
Rest period between sets
The Holten Curve
100%
5-10 sec
isometric
95%
90%
10-15 sec
isometric
% of 1
RM
85%
1 rep
2 reps
4 reps
7 reps
20-30 sec 80%
isometric
11 reps
75%
16 reps
40-50 sec 70%
# of
reps
22 reps
endurance
25 reps
isometric
50-60 sec
isometric
Repetition Domains: Cross over
strength
65%
60%
30 reps
SAMPLE EXERCISE PRESCRIPTION
Repetition Science
REPS % of RM
RHYTHM
REST
GOAL
INTERVAL
25
40%
slow
1 min
muscle endurance
8
70%
explosive
5 min
power
6
80%
slow ecc;
2 min
medium conc
hypertrophy
4
90%
slow
5 min
maximum strength
2
>100%
eccentric
slow
5 min
maximum strength
based on one repetition single lift capacity
ENDURANCE
•
3 sets of 15-25 reps
(one minute) at 40-50%
of SLC
Monday: 3 sets of 8 reps at
80% of SLC
• Wednesday: 3 sets of 4 reps
at 90% of SLC
• Friday: 3 sets of 6 reps at
80% of SLC
• Each of these would have a
different motor unit
recruitment pattern
* single lift capacity re-determined each week
Another way to incorporate “Rhythm or
Tempo” into the equation.
strength gains
% contribution
•
MASTERY of EXERCISE CRITERIA
muscular
hypertrophy
neural recruitment
Biomechanically correct movement with demonstration of
control
No substitution patterns or tendencies
Minimal perception of exertion
I-D-F goal accomplished
Non-symptom producing
•
•
•
time (weeks of training)
STRENGTH-POWER
•
•
no residual soreness (DOMS)
no increase in pain or stiffness reported
no increase in swelling
“like black smoke coming out of an engine”
no increase in redness or palpable cutaneous skin
temperature
no decrease in function reported or observed
REHABILITATION
PROGRESSION VARIABLES
How to Change the Challenge
Easy
Hard
Simple
Complex
Safe
Provocative
Known
Unknown
REHABILITATION
PROGRESSION VARIABLES
SIMPLE
COMPLEX
train a muscle
asymptomatic single
plane motion
symmetrical
train a movement
multiple or triplane
motion
asymmetrical or
reciprocal
unilateral
coordinate
bilateral
isolate
REHABILITATION
PROGRESSION VARIABLES
KNOWN
ENVIRONMENT
UNKNOWN
ENVIRONMENT
REHABILITATION
PROGRESSION VARIABLES
EASY
proactive movement
stable support surface
reactive movement
unstable or changing
support surface
HARD
anti-gravity
maximal intensity
(slow twitch recruitment)
recruitment)
(fast twitch
body weight only
short lever arms
body weight +
external overload
long lever arms
REHABILITATION
PROGRESSION VARIABLES
SAFE
PROVOCATIVE
protected arc of motion
visual input
full arc of motion
“blind”
Points of Emphasis
gravity assisted or eliminated
submax intenisty
transitional movement
biomechanically correct control
and movement
movement and exercise in
non-symptom producing planes
and motions
don’t tweak of change the exercise because you are
bored - does the patient need the challenge or
change?
understand the “science of specificity”
“Make rehab fun”
fun”
Is your
patient
carrying their
share of the
load?
Thank you.
Science and Clinical Application of
Electrotherapeutic Modalities
Julie DeVahl, PT, MS
Assistant Professor
Department of Physical Therapy
Historical Perspective
z
z
z
z
Technology Today
400 BC: Torpedo fish
Middle 1700’s: storage of
electricity
Middle 1800’s: physiology
of underlying electrotherapy
Early 1900’s: most
physicians used some form
of electrotherapy.
Course Objectives
z
Describe the theory of pain management with
electrical stimulation
z
Compare physiology of electrically stimulated
and volitional muscle contractions
z
Identify strategies for electrode placement
z
Select stimulation parameters for effective
pain management and neuromuscular
rehabilitation programs
Historical Perspective
z
z
1919 “Electreat”
1960’s TENS and
NMES
Terminology
z
TENS pain management
–
–
z
Acute, well-defined
Ch i diff
Chronic,
diffuse
NMES muscle contractions
–
–
–
–
–
–
Strengthening
Treatment of disuse atrophy
Increase and maintain range of motion
Muscle re-education and facilitation
Spasticity management
Orthotic substitution
1
Terminology
z
z
EMS stimulation of
denervated muscle
FES multi-channel to
restore function
Electrotherapy
for Pain Management
Much of what we do to treat
patients’ pain is to change their
patients
perception of pain.”
Bishop Phys Ther 1980
Electrode Placement Strategies for
Pain Management
z
Acute and/or well-localized pain
–
–
–
z
Electrode Placement Strategy:
Bracket Structure
Bracket structure
S
Structure
and
d iinnervation
i
Radiating pain pathways
Chronic and/or diffuse pain
–
Motor, trigger or acupuncture points
Electrode Placement Strategy:
Bracket Structure
Electrode Placement Strategy:
Bracket Structure
2
Electrode Placement Strategy:
Bracket Structure and Innervation
Electrode Placement Strategy:
Pain Pathway
Electrode Placement Strategy:
Electrode Placement Strategy:
Motor, Trigger and Acupuncture Points
Motor, Trigger and Acupuncture Points
B11
St34
Sp10
Si 11
St36
Upper back pain
St36
“Z”
Knee pain
Electrode Placement Strategy:
Motor, Trigger and Acupuncture Points
Gb31 Low back and lateral
Leg pain
Electrode Placement Strategy:
Motor, Trigger and Acupuncture Points
Li16
Li14
Gb34
Li10
Li4
3
Trial Electrodes
Point Finding Technique
Stimulation Parameters for Pain
Management
Stimulation Parameters for Pain
Management
z
Acute and/or well-localized pain
–
–
–
–
z
z
Amplitude: sensory
Phase duration: short (<150 µsec)
sec)
Frequency: high (usually 80-150 pps or beats/sec)
Mechanism: Gate theory, enkephalin release
Chronic and/or diffuse pain
–
–
–
–
Amplitude: mild motor (if over contractile tissue)
Phase duration: long (>150 µsec)
Frequency: low (1-10 pps or bursts/sec)
Mechanism: β-endorphin release
Physiologic Effects of NMES
z
Research with animal models:
– Low Freq TENS (4 pps) triggers release of serotonin
spinally and activates serotonin receptors, 5-HT2
and 5
5-HT3,
HT3 muscarinic and mu
mu-opioid
opioid receptors
supraspinally.
– High Freq TENS (100 pps) triggers release of GABA
and decreases glutamate levels spinally and
activates delta-opioid and muscarinic receptors in
the spinal cord and delta-opioid receptors
supraspinally.
Review of TENS basic science and clinical
effectiveness. Sluka and Walsh. J Pain. 2003.
Muscle Fiber Types
Type I
Type IIa
Type IIb
http://www.neuro.wustl.edu/neuromuscular/pathol/2atroph.htm
4
Motor Unit
Motor Unit Classification
Muscle fibers
Nerve axon
Nerve cell body
Energy source
Voluntary
E-Stim
Recruitment of
motor units
i
Type I (smaller)
1st
Type II (larger)
1st
Firing frequency
Asynchronous
Slower (2-10Hz)
Less fatigue
Synchronous
Faster (30-75 Hz)
More fatigue
Disuse Atrophy
Type II (a/b)
Fast twitch
Oxygen
Oxygen/Glycogen
Contraction speed
Slow
Fast
Endurance
High
Medium/Low
Fatigue
Slow
Medium/Fast
Strength/Force
Low
High
Static
Postural
Dynamic
Explosive
Function
Differences in Voluntary & Electrically
Stimulated Contractions
Type I
Slow twitch
Disuse Atrophy
z
Refers to the changes in
the muscle after a period
of immobilization or
reduced activity
z
Decrease in the crosssectional area of the
muscle belly, with type II
muscle fibers being
affected to a greater
degree
Role of NMES
I
II
Low-level voluntary exercise targets
Type
yp I fibers
z E-stim recruits Type II fibers first, then
Type I as amplitude increases
z Combined E-stim and exercise beneficial
during early rehab programs
z
5
Are there muscle adaptations to
training with electrical stimulation?
Electrode Placement for
Quadriceps
Vastus Lateralis muscle biospy following 10 weeks of NMES
Munsat, McNeal and Waters (1976) Arch Neurol 33:608-617
Electrode Placement for
Quadriceps
Electrode Placement
for Hamstrings
Clinical Goal: Muscle Conditioning
NMES Clinical Goal: Strengthening
z
z
z
Intermittent high force stimulation
Æmuscle overload Æ
STRENGTHENING
z
Prolonged low force stimulation
Æmovement repetitionÆENDURANCE
Strength of
stimulated
contraction should be
60% off MVC
For individuals with
disuse atrophy,
stimulated
contraction should be
greater than patient’s
volitional contraction
Medtronic, Inc.
6
NMES Clinical Goal: Strengthening
Strengthening-Medium Frequency
Stimulation
Mode: Contract/Relax,1:5 ratio
(10sec on, 50 sec off)
z Amplitude: maximal motor recruitment
z Frequency: 50 bursts/sec or pps
z Phase Duration: 200-300 µsec
z Rx Time: 10 min (10 maximal
contractions) every other day
z
NMES Clinical Goal:
Endurance Program
Determination of
Total Stimulation Time
Mode: Contract/Relax, 1:3-1:5 ratio
z Amplitude: Submax. motor
z Frequency: 30-50 pps
z Phase Duration: 300 µsec
z Rx Time: 30-60 min actual contraction
(2-4 hours)
TT = Ts
z
What does the patient do during
2-4 hours of NMES?
z
z
z
Start with multiple shorter session
Volitional effort with a portion of the session
– Home exercises
Allow NMES to cycle during remainder of session
– Work at a desk
– Do homework
– Read the newspaper
– Watch TV
__________
(T1+T2)
T1
TT = Total time
Ts = Stim time (sec)
T1= on cycle (sec)
T2= off cycle (sec)
60 min stim with On:
Off set at 4:12 sec
TT = 3600 (4+12)
4
TT = 900(16)
TT =14,400 sec
240 min= 4 hours
NMES Clinical Goal:
Muscle Re-education
Mode: Contract/Relax 1:1 ratio
Amplitude:
p
Submax. motor
z Frequency: 30-50 pps
z Phase Duration: 300 µsec
z Rx Time: 10-15 min. (up to 30 minutes)
z Patient must work with the stimulation!
z
z
7
Functional Retraining
Closed Chain Activities with Limited Weight-bearing
Functional Retraining
Agility and Plyometrics
Functional Retraining
Closed Chain and Balance
Functional Retraining
Closed Chain with Motor Control and
Balance Activities
Functional Retraining
Closed Chain, Motor Control and Stability
Functional Retraining
Plyometrics with Limited Weight-bearing
8
Functional Retraining
Plyometrics with Full Weight-bearing
Modified Electrode Placement
z
z
z
Postural Muscle Re-education
z
z
Helpful Hints…
z
Middle and lower
traps
Can use bilateral or
unilateral
–
–
z
z
z
z
z
Baker LL, Wederich CL, McNeal DR, et al. NeuroMuscular
Electrical Stimulation. A Practical Guide. 4th Edition. 2000.Los
Amigos Research & Education Institute, Inc. Downey, CA.
www.RanchoREP.org
Delitto A, Rose SJ, McKowen JM, et al. Electrical stimulation
versus voluntary exercise in strengthening thigh musculature after
anterior cruciate ligament surgery. Phys Ther. 1988;68:660-663.
Fitzgerald GK, Piva SR, Irrgang JJ. A modified neuromuscular
electrical stimulation protocol for quadriceps strength training
following anterior cruciate ligament reconstruction. J Ortho Sports
Phys Ther. 2003;33:492-501.
Gorgey AS, Dudley GA. The role of pulse duration and stimulus
duration in maximizing normalized torque during neuromuscular
electrical stimulation. J Orthop Sports Phys Ther. 2008;38:508516.
Lower electrical resistance
–
z
References
2 channels/3
electrodes
O er each head of
Over
the gastroc
Shared electrode at
muscle/
tendinous junction
(soleus)
Trim hair
Prepare skin
Be specific with electrode
placement
Use large electrodes for
NMES and combine with
exercise
Use TENS as a tool to meet
mobility goals
References
z
z
z
z
z
Gregory CM, Bickel CS. Recruitment patterns in human skeletal
muscle during electrical stimulation. Phys Ther. 2005;85:358-364.
Kim K, Croy T, Hertel J, et al. Effects of neuromuscular electrical
g
reconstruction on
stimulation after anterior cruciate ligament
quadriceps strength, function, and patient-oriented outcomes: a
systematic review. J Orthop Sports Phys Ther. 2010;40:383-391.
Lamm KE. Optimal Placement Techniques for TENS. A Soft
Tissue Approach. Course Lab Manual. Tuscon, AZ. 1989.
Munsat TL, McNeal DR, Waters RL. Preliminary observations on
prolonged stimulation of peripheral nerve in men. Arch Neurol.
1976;33:608-617.
Sjolund BH, Eriksson MBE. The influence of naloxone on
analgesia produced by peripheral conditioning stimulation. Brain
Res. 1979;173:295-301.
9
References
z
z
z
z
z
Sluka KA, Walsh D. Transcutaneous electrical nerve stimulation: Basic
science mechanisms and clinical effectiveness. J Pain. 2003;4:108-121.
Snyder-Mackler L, Delitto A, Bailey S, et al. Quadriceps femoris muscle
strength and functional recovery after anterior cruciate ligament
reconstruction: a prospective randomized clinical trial of electrical
stimulation. J Bone Joint Surg. 1995;77:1166-1173.
Stevens JE, Mizner RL, Snyder-Mackler L. Neuromuscular electrical
stimulation for quadriceps strengthening after bilateral total knee
arthroplasty: a case series. J Orthop Sports Phys Ther. 2004;34:21-29.
Yu J, Carroll. Electrode Placement Manual for TENS. Medtronic, Inc.
San Diego, CA. 1982.
Vance CGT, Radhakrishnan R, Skyba DA, Sluka KA. Transcutaneous
electrical nerve stimulation at both high and low frequencies reduces
primary hyperalgesia in rats with joint inflammation in a time-dependent
manner. Phys Ther. 2007;87:44-51.
10
Lecture Objectives
Therapeutic Ultrasound: Review of
Concepts and Clinical Application
Ross Querry, PT, PhD
Associate Professor
Department of Physical Therapy
Ultrasound
Review the inherent physical properties of how US energy may
work in a physiological system
Develop a critical understanding that the US prescription is
specific for each clinical application
Evaluate specific techniques of application of therapeutic US and
how they may be modified to achieve treatment goals
Review clinical evidence to the efficacy of US and how our
decisions assist or detract from the body of evidence when
applied to our patients
Ultrasound
Modality used for a number of purposes
–
Diagnosis
Definition: inaudible, acoustic, mechanical vibrations of high
frequency that produce thermal and non-thermal effects
First reported in medical literature in Germany in the 1930’s
Application of therapeutic US based partially on military research
from WWII
Council on Physical Medicine & Rehabilitation of the AMA
Echocardiography
Echocephalography
Doppler
Blood Flow
Doppler
Obstetrical
–
Surgical
–
Therapeutic
Gallstone
–
ablation
Beam Non-Uniformity Ratio (BNR)
Physical Properties of Ultrasound
Recommended therapeutic US as an adjunctive therapy for the
treatment of pain, soft tissue injury, and joint dysfunction in 1955
Acoustic energy relies
on molecular collision for
transmission
Mechanical wave in
which energy is
transmitted by molecular
vibration of medium
through which it travels
We are attempting to
produce physiological
effects from this acoustic
energy
Ratio at the highest intensity
(W/cm2) found in the near zone to
the average intensity (W/cm2)
Smaller the ratio difference of the
BNR, the more homogenous the
US beam
Ideal: 2:1 to 6:1 BNR. Greater the
ratio difference, the greater the
potential for hot spots.
Forms of Energy Absorption
Actual BNR Diagrams
Reflection: Occurs at interfaces when ultrasound travels
from one tissue to another
Acoustic impedance: Determines amount of energy
transmitted or reflected at tissue interfaces
Refraction: Deviation of sound waves which occurs at
tissue interfaces
Standing Wave Generation
Treatment Decision Variables
Interaction of incident waves
and tissue interfaces have
influence on how standing
waves are created.
Do you make a decision with a
rationale for each one of
these! Or does everyone in
the clinic get the same
treatment?
This will be greatest in bone
(reflected), least in tissues with
high water content (transmitted)
Frequency
Frequency
Number of Oscillations in 1
second (Hertz)
Rate of absorption and
attenuation increases as
frequency increases
3.0 MHz is absorbed 3x faster
than 1.0 MHz
– Key variable in deciding in
intensity prescription
Therapeutic US
–
.75 - 3.3 MHz (1,000,000
cycles/s)
Frequency determines depth
of penetration and rate of
heating!!!
The faster rate of absorption =
faster peak heating of tissues
3.0 MHz US heats human
muscle 3x faster than 1.0 MHz
US!
Effective Radiating Area (ERA)
Portion of the transducer
that actually produces
the sound wave
Closer the ERA and the
transducer size the
better to ensure more
consistent contact and
therapeutic dose in the
treatment area
= 4.62 cm2
About a 5 cm2
Sound head
??? How big of an area
did you treat with US as
a PT tech?
3 ERA
ERA always smaller than
the transducer
Treatment Area and Duration
Effective Radiating Area (ERA)
Treatment duration is dependent upon
–
–
–
–
The surface area treated
Treatment goals
Frequency, why
Sound head ERA
Selecting Pulse Ratio
Depends on the state of the target tissue
The more acute the tissue, the more “energy
sensitive” it is
–
–
Surface area (cm2) receiving treatment should
be no greater than 1.5 - 3 x the ERA of the
transducer for the recommended intensity and
duration
Intensity
–
–
Not the same as time since injury. Why?
Appears to respond to larger ratios (lower duty cycles)
As tissue moves away from acute, favors smaller ratios
(smaller cycles)
1:4…1:3…1:2…1:1…continuous
Therapeutic Effects
Treatment recommendation:
–
–
Lowest intensity at the frequency that will
transmit the necessary US energy to the
desired tissue should be used
Research is supporting that many of our
treatments are too low in intensity, too short
in time, too infrequent = too little effect for
significant impact. (Systematic review PT
Journal , January 2010)
Thermal and
Non-Thermal
Thermal Effects of Ultrasound
Thermal Effects - Vascular
Increased blood flow, diffusion rates, and membrane
permeability, enzymatic activity
Mild inflammatory response that may help in the
resolution of chronic inflammation
–
–
1°C tissue temp increase or mild
–
Reduction of muscle spasms
Modulation of pain: Increased nerve conduction
velocity and increased pain threshold
Decrease in joint stiffness
–
Tissue with poor vascular supply:
2-3°C tissue temp increase or moderate
Vascular muscle tissue:
–
Increase in the extensibility of collagen fibers found in
tendons and joint capsules
–
–
4°C tissue temp increase or vigorous
Absorption of ultrasound is in direct proportion to the
protein content of the tissues sonated
Tissues that are selectively heated by ultrasound:
–
–
–
–
–
–
superficial bone
joint capsules
tendon
scar tissue
peripheral nerves
cell membranes
Cavitation: bubble formation in
tissue due to expansion and
contraction of gases
Stable: Beneficial by increasing
flow in fluid around vibrating
molecules
Unstable or transient cavitation:
large excursions in bubble volume
causing collapse after only a few
cycles
–
Remember relationship of frequency to heating rage
Non-thermal theoretical mechanism
1MHz at 1 W/cm2 inc. 0.2 deg/min
3MHz at 1 W/cm2 inc. 0.6 deg/min
Non-thermal Effects of US
Thermal Effects
1MHz at 1 W/cm2 inc 0.86 deg/min
3MHz at 1 W/cm2 inc. 2 deg/min pat tendon
Related to high intensity, low
frequency US, and to “hot spots”
Non-thermal Effects of US
Acoustic streaming (microstreaming):
–
increases the cell diffusion rate of ions and metabolites
across the cell membrane and increases the fluid
interchange
As long as the cell membrane is not damaged,
acoustic streaming can be of therapeutic value is
accelerating the healing process
Non-thermal Effects
Therapeutic Goals
Tissue regeneration and soft tissue repair
–
–
Pitting Edema:
–
Continuous 3MHz US with 1-1.5 W/cm2
Scar Tissue and Joint Contracture:
–
–
Increased tissue temperatures increase elasticity and decrease
viscosity of collagen fibers
Continuous US: 0.5 - 2.0 W/cm2
Chronic Inflammation:
–
–
Results are equivocal:
Overall: Pulsed US may be effective in increasing blood flow for
healing, and for pain reduction through heating. Thermal energy
needed for pro-inflammatory response
Indications for Ultrasound
Resorption of Calcium
Deposits
–
Soft Tissue Healing and Repair (pulsed US)
–
–
Results are strong but
limited studies: Shoulder
Bone Fractures
–
–
–
–
Dose: 0.1 - 0.2 W/cm2 cont US, or
1.0 W/cm2 20% pulsed US
Indications for Ultrasound
Maximizes inflammatory – proliferation –remodeling
phases
Edema reduction
Decreased acute muscle spasm and pain
Phonophoresis
–
Commonly Stated
Indications for Ultrasound
Overall: Evidence does
support use of US
Special US bone
stimulators available
–
US thought to accelerate inflammatory phase of
healing. Pro-inflammatory
Single treatment actually stimulate release of
histamine from mast cells
Histamine attracts polymorphonuclear leukocytes
that “clean up” debris and monocytes
Suggested treatment protocol: After bleeding stops,
within 1st few hrs of injury
.5 W/cm2-pulsed US or .1W/cm2 - continuous
USx5’
Indications for Ultrasound
Stretching of Connective
Tissue
– “Stretching Window”
stretch during US
application
– 3 MHz : (1.2cm depth)
Temperature remained in
vigorous heating for 3.3
minutes
– 1 MHz: (4 cm depth)
Temperature decreased 1
deg in 2’ and another 2 deg
in 5.5’
Ineffective Ultrasound Treatment
Can Occur Because:
Diluting the treatment dose… too much area
Failure to identify the location, breadth, and
depth of the target tissue (s)
Improper frequency to reach target tissues
Selection of a poor beam profile
Inadequate or excessive intensity levels
Failure to select the duty factor that will provide
the correct amount of thermal or non-thermal
effects
Failure to maintain and calibrate equipment
Cochrane Reviews
Cochrane Reviews
Updated Jan. 2009, same conclusion
Cochrane Reviews
Update US and Knee OA
PT Journal
January 2010
Consensus is most US
dosage in research is
under dosed
Methodology is poor
We are our own worst
enemy
–
Rutjes, AW, Update Jan 2010
Summary
US is still one of the most widely utilized modalities
Proper clinical application at a minimum requires
specific thought to the physical properties of US and a
rationale based patient prescription
Research findings are mixed at best ad most often
unfavorable
Poor methodology is most often stated limitation of
studies
Critical thinking for
clinical application
Low Level Laser Therapy: Principles,
Application, and Evidence
Ross Querry, PT, PhD
Associate Professor
Department of Physical
Therapy
Laser & Light: History
By the end of the 60’s, Endre Mester
(Hungary) –
In early 1962, the 1st low level laser was
developed.
In Feb. 2002, the MicroLight 830 (ML830)
received FDA approval for Carpal Tunnel
Syndrome Treatment (research treatment)
Review the inherent physical properties of how Low Level Laser
energy may work in a physiological system
Develop a critical understanding that the Low Level Laser
prescription is specific for each clinical application
Evaluate specific techniques of application of Low Level Laser
Therapy and how they may be modified to achieve treatment
goals
Review clinical evidence to the efficacy of Low Level Laser
Therapy and how our decisions assist or detract from the body of
evidence when applied to our patients
What is Laser Therapy?
Light Amplification by the
Stimulated Emission of Radiation
Compressed light of a
wavelength from the cold, red
part of the spectrum of
electromagnetic radiation
Laser therapy – has been studied in Europe
for past 25-30 years; US 15-20 years
Naming References
was reporting on wound healing through laser
therapy
Lecture Objectives
Therapeutic Laser
Low Level Laser
Therapy (3LT)
Low Power Laser
Therapy
Low Level Laser
Low Power Laser
Low-energy Laser
Soft Laser
Low-reactive-level Laser
Monochromatic - single frequency,
single color
Coherent – the waves are in phase
with one another
Directional- exhibits minimal
divergence, beam is concentrated
What is Low Level Laser Therapy (3LT)
Low-intensity-level Laser
Photobiostimulation
Laser
Photobiomodulation
Laser
Mid-Laser
Medical Laser
Biostimulating Laser
Bioregulating Laser
The application of red and
near infrared light over
injuries or wounds to
improve soft tissue healing
and relieve both acute and
chronic pain.
Not intended to produce
heat
Types of Lasers
High “Hot”
Surgical Lasers
Hard Lasers
Thermal
Energy – 3000-10000 mW
–
–
–
–
Parameters
Low “Cold”
–
–
–
–
–
–
Medical Lasers
Soft Lasers
Subthermal
Energy – 1-500 mW
Therapeutic (Cold) lasers
produce maximum output
of 90 mW or less
600-1000 nm light
Parameters - Wavelength
Nanometers (nm)
Longer wavelength (lower
frequency) = greater
penetration
–
600-1300nm: optimal depth of
penetration in human tissue (14cm)
Intensity of laser alters the clinical effects
within the tissue
–
–
–
–
–
–
Make incisions and cauterize during surgery
Sterile, allows fine control, cauterize as it cuts=less
scarring
Low-intensity “cold” laser facilitate healing
Same intensity will have different effects on
different tissues
Wavelength
Output power
Average power
Intensity
Dosage
Parameters – Power
Output Power
–
–
–
–
Watts or Milliwatts ( W or mW)
The rate of energy flow
Important in categorizing laser for
safety
Fixed
Power Density (intensity)
–
–
W or mW/cm2
Amount of power per unit area
Parameters – Energy Density
High-intensity “hot” lasers heat and destroy tissue
Laser
–
Wavelength is affected by
power
Parameters-Intensity
Dosage (D)
Amount of energy
applied per unit area
over entire treatment
time
Measured in
Joules/square cm
(J/cm2)
–
–
Joule – unit of energy
1 Joule = 1 W/sec
Most laser and light
therapy devices allow for
selection of energy or
energy density.
Various dosage ranges
per site (1-9 J/cm2)
Parameters – Energy Density
Recommended Dosage
Range
Dependent on application and
stage of healing
Recommendations vary within
the literature
– This is a primary area
where inconclusive or
conflicting results may
apply
Ardnt-Schultz Principle
WALT
WALT Resources
World Association of Laser Therapy
http://www.walt.nu
Dosage Recommendations
Scientific Recommendations
Other resource links
–
Arndt-Schultz Law – dosage matters
Substances vary in action
depending on whether the
concentration is high,
medium, or low.
For 3LT
–
–
–
Low dose may
understimulate
High concentrations
suppress or cause
detrimental effects
Therapeutic window is the
goal
Who do we trust for this
dosage?
Dosage Table 904 nm 3T
(780-860 nm avail. on site)
How to design/evaluate RCTs/SRs/MAs
Dosage Table 904 nm 3T
(780-860 nm avail. on site)
Physiological Effects of 3LT
Biostimulation – improved metabolism, increase of cell
metabolism
–
Increases speed, quality & tensile strength of tissue repair
–
More than 50 light sensitive molecules and substances have
been identified in our cells and tissue
Improved blood circulation & vasodilation
Increases ATP production
Analgesic effect
Anti-inflammatory & anti-edematous effects
–
–
–
Increases blood supply
Relieves acute/chronic pain
Reduces inflammation
Physiological Effects of 3LT
Stimulation of wound healing
–
–
Increase collagen production
Increase macrophage activity
–
Red light affects all cell types
–
Promotes faster wound healing/clot
formation
Helps generate new & healthy cells &
tissue
–
Tissue and Cellular Responses
–
Develops collagen & muscle tissue
–
Stimulates immune system
Alter nerve conduction velocity
–
Stimulates nerve function
Tissue and Cellular Responses
Infrared light is more
selective absorbed by
specific proteins in the cell
membrane & affects
permeability directly
Thought to be the primary
contributor to many clinical
benefits of laser and light
therapy especially with tissue
healing
Absorbed by the mitochondria
present in all cells
Cytochromes (respiratory chain
enzymes) within the mitochondria
have been identified as the
primary biostimulation
chromophores (primary lightabsorbing molecules).
Enzymes are catalysts with the
capability of processing
thousands of substrate
molecules, they provide
amplification of initiation of a
biological response with light.
Key Metabolic Action Site
Cytochromes function to couple the
release of energy from cellular
metabolites to the formation of high
energy phosphate bonds in
adenosine triphosphate (ATP)
–
ATP is used to drive cell
metabolism (maintain membrane
potentials, synthesize proteins &
power cell motility & replication).
Assuming cytochromes also can
absorb energy directly from
illumination, it is possible that
during LLLT light energy can be
transferred to cell metabolism via
the synthesis of ATP.
Tissue and Cellular Responses
Magnitude of tissue’s reaction are
based on physical characteristics of:
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Output wavelength/frequency
Density of power
Duration of treatment
Vascularity of target tissues
Direct effect - occurs from absorption
of photons
Indirect effect – produced by
chemical events caused by
interaction of photons emitted from
laser & the tissues
J Photochemistry & Photobiology, Jan 2009
Effects of Laser and Light: Modulate
Inflammation
Associated with:
Increased levels of prostaglandin F2α
, interleukin-1α, and interleukin-8
Decreased levels of PGE2 and tumor
necrosis factor
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Lymphedema
64 Participants; 27 received placebo followed by laser; 37 received 2 x 3
weeks laser
significant improvements after 2 x laser in
affected arm (maintained at 1 - 3 months)
trunk (maintained at 1 - 3 months)
Found to promote proliferation of
various cells and increase
immune response through
activation of T and B lymphocytes
Fibroblasts
Keratinocytes
Endothelial Cells
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Effects of Laser and Light: Promote
Vasodilation
Thought to occur by stimulation of
microcirculation through release of
preformed nitric oxide
Vasodilation can accelerate
healing
decreases affected limb volume
decreases whole upper body fluid
improves tonometry of upper arm and posterior torso
Carati CJ (2004). Am J Oncology Review 3: 255-60
Carati CJ (2003). Cancer, 98: 1114-22
Effects of Laser and Light: Alter Nerve
Conduction Velocity and Regeneration
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Greatest effects noted with red
laser and over the site of nerve
compression
Conflicting findings in the
literature
Effects:
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Increased oxygen and other
nutrients
Removal of waste products
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Wound and Fracture Healing
Study outcomes are mixed
Red or IR light 5-24 J/cm2 most effective
Doses above 16-20 J/cm2 may inhibit wound healing
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Stimulation of leukocytic phagocytosis and fibroblast proliferation, increasing
collagen synthesis and procollagen RNA levels, improving circulation and
inhibiting bacterial growth
Acceleration of fracture healing
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Musculoskeletal Disorders
4-16 most recommended
Begin at lower end and progress as tolerated
Acceleration of wound healing
Increased tensile strength of wound
Increased collagen content
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Well-documented clinical trials still needed
Increase rate of hematoma absorption, bone remodeling, blood vessel
formation, calcium deposition and macrophage, fibroblast and chondrocyte
activity
Increased nerve conduction
velocities
Increased frequency of action
potentials
Decreased distal sensory latencies
Accelerated nerve regeneration
Induce axonal sprouting and
outgrowth of cultured nerves and in
in vitro brain cortex
Studies are mixed, however a meta
analysis reported on average low-level
laser therapy has been found more
effective than placebo for the treatment
of musculoskeletal disorders
Arthritic and Soft tissue conditions
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Treatment of RA:
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Increased hand grip strength and flexibility
Decreased pain and swelling
Treatment of OA:
Decreased pain and increased grip strength
(hands)
Decreased pain and improved function
(cervical)
Pain Management
Reduce pain and dysfunction associated
with musculoskeletal conditions
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Exercise with Laser Most Effective Therapy
Castano AP, Lasers Surg Med 2007 Jul;39(6):543-50
TMJ Pain and 3LT
A well-designed study was performed using laser therapy on
patients who had low back pain for at least 12 weeks. Laser
therapy was performed twice a week for 6 weeks along with
exercise therapy and compared to exercise and laser alone as
controls. In these patients, laser therapy combined with exercise
was more beneficial than exercise without laser. This study
demonstrates that laser can be an excellent adjunct for
practitioners who emphasize exercise therapy for their patients
and produces better results than exercise alone.
A common problem in older patients as
well as diabetics and workers exposed to
toxic chemicals. Often challenging for
modern medicine.
This study found that laser therapy
improved spatial perception,
demonstrating improved nerve function,
as well as improved EMG study
outcomes. These positive results support
previous research that documented that
laser can regenerate nerve tissue.
Peric Z, 2007 May-Jun;135(5-6):257-63
Mazzetto MO, Cranio
2007 Jul;25(3):186-92
This study investigated TMJ
pain and Laser therapy.
Results confirmed the results
of previous studies noting that
laser was more effective than
placebo at reducing TMJ
pain.
Djavid GE, Aust J Physiother 2007;53(3):155-60.
3LT for Peripheral Neuropathy
Laser as Effective as Cortisone!
Rats with arthritis were exposed to a number of different laser
protocols. It was found that illumination with 810-nm laser was
almost as good as cortisone at reducing
swelling! It was found that higher doses were more important and
more effective than any other parameter. Laser therapy not only
reduced joint swelling but also
correlated with decreased serum prostaglandins, a common
marker of inflammation.
Arthritis
Lateral epicondylitis
Low back pain
Neck pain
Trigger points
Chronic pain
3LT and Low Back Pain
Arthritis Anti-inflammatory Impact
The efficacy of low-power lasers in tissue repair and pain
control: a meta-analysis study.
Findings in review of 34 research papers
mandate the conclusion that laser
phototherapy is a highly effective
therapeutic for tissue repair and pain
relief.
Enwemkea CS, et. al. Photomed Laser Surg. 2004 Aug;22(4):323-9.
THERMOGRAPHIC STUDY OF LOW LEVEL LASER
THERAPY FOR ACUTEACUTE-PHASE INJURY
THERMOGRAPHIC STUDY OF LOW LEVEL LASER
THERAPY FOR ACUTEACUTE-PHASE INJURY
In acute phase, tissue
temp rose around
trauma site (42°C) and
reduced in peripheral
area (29°C)
After LLLT irradiation,
skin temperature fell 3°
C in trauma area and
rose 3°in peripheral
area reaching normal
temperatures
Rapidly improved
blood and lymphatic
flow and alleviated
swelling and edema
Asagai, Y. et al. Laser Therapy, 2001
Asagai, Y. et al. Laser Therapy, 2001
THERMOGRAPHIC STUDY OF LOW LEVEL LASER
THERAPY FOR ACUTEACUTE-PHASE INJURY
Asagai, Y. et al. Laser Therapy, 2001
3LT and Exercise
Am J Sports Med 2008 36: 881
Lancet, Vol 374, December 2009
Effects of Low-Level Laser Therapy (LLLT) in the Development of ExerciseInduced Skeletal Muscle Fatigue and Changes in Biochemical Markers Related
to Postexercise Recovery
Effects of Low-Level Laser Therapy (LLLT) in the Development of ExerciseInduced Skeletal Muscle Fatigue and Changes in Biochemical Markers Related
to Postexercise Recovery
3LT and Lateral Epicondylitis: EBP in
action, but never stop learning!
Maher, S. Physical Therapy . Volume 86 . Number 8 . August
2006
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Bjordal, JM. Letter to the Editor; Physical Therapy . Volume 87 .
Number 2 . February 2007 (Dr. Bjordal is international expert on
3LT)
Maher, S. Author Response; Same issue
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Summary
Low Level Laser energy has the ability to stimulate photosensitive
receptors in multiple biological tissues
Although empirical and clinical findings show positive results,
there is conflicting data and methodological concerns
More controlled studies using proper dosing and rigorous
methodology are needed to determine the types of laser and
dosages that are required to attain reproducible results for
therapists
Low Level Laser Therapy has potential to become a valuable tool
in rehabilitation, but it is an example of how understanding the
technology is crucial for clinical application
Evidence in Practice article looking at systematic review of 3LT for
lateral epicondylitis
Clinical decision based on SR: 3LT not effective
Brings up critical limitations in the SR search and in interpreting
research on 3LT
Explains how the original EBP article was an exercise how how to
apply research evidence to clinical decisions, but also reinforces
limitations of SRs