OSTEOARTHRITIS

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A. Definition
Osteoarthritis according to the American College of Rheumatology is a
heterogeneous group of conditions that lead to joint signs and
symptoms.Osteoarthritis (OA) is the most common form of arthritis and one of
the leading causes of disability. The knee is the largest synovial joint in humans,
consisting of bony structures (distal femur, proximal tibia, and patella), cartilage
(meniscus and hyaline cartilage), ligaments and synovial membrane. The latter is
responsible for the production of synovial fluid, which provides lubrication and
nutrition to the avascular cartilage. Unfortunately, given the high usage and stress
of this joint, it is a frequent site for painful conditions including OA. 7 It is also
recognized that cartilage tissue is not the only tissue involved. Due to its lack of
blood vessels and innervation, cartilage by itself is incapable of producing
inflammation or pain at least in the early stages of the disease. Therefore, The
main source of pain comes from changes in the noncartilaginous components of
the joint, such as the joint capsule, synovium, subchondral bone, ligaments, and
periarticular muscles. As the disease progresses, these structures are affected and
changes including bone remodeling, osteophyte formation, periarticular muscle
wasting, ligament laxity, and synovial effusion may become evident.This disorder
is a degenerative process in the joints that affects the knee joint.

B. Knee Anatomy

1. Knee Joint Bones

The knee joint is formed by several bones, namely:
a. Femur
The femur is the longest tubular bone. The framework at the base
of which is connected to the acetabulum forms a joint head called the
head of the femur. Above and below the columna femoris there are
spurs called the trochanter major and trochanter minor, at the ends
forming the knee joint, there are two protrusions called the condylus
medianus and condylus lateralis. Between these two condyles there is
an indentation where the kneecap bone (patella) is located which is
called the condylar fossa.

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 b. Tibial Bone
The tibia bone is a smaller bone, attached to the fibular bone at the
base, forming a joint with the peduncle of the foot at the end and there
is a taju called the median malleolus bone.
c. Fibula Bone
The fibula is the largest tubular bone after the femur which forms
the knee joint with the femur at the end having a bulge called the
lateral malleolus or the outer ankle.
d. Patellar Bone
In flexion and extension the patella moves on the femur. The
distance between the patella and the tibia when movement occurs is
fixed and what changes is only the distance between the patella and the
femur. The function of the patella besides acting as an attachment to
the muscles or tendons is as a lever for the knee joint. Under
conditions of 90 degrees the position of the patella between the two
condyles of the femur and during extension the patella lies on the
anterior surface of the femur.

Figure 1. Anatomy of a normal knee joint 3

2. Muscle
a. Knee Extensor Muscles (Quadriceps Femoris)

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 The quadriceps femoris muscle is one of the skeletal muscles found
on the front of the human thigh. This muscle has the dominant function of
extension at the knee. The quadriceps femoris muscle consists of four
muscles, namely:

Figure 2. Quadriceps Femoris Muscle3

i. Rectus Femoris muscle

It is located most superficially on the ventalis surface between the
other quadriceps muscles, namely the NPRStus lateralis and medialis
muscles. It originates at the anterior inferior iliac spine (caput rectum)
and at the ilium in the cranialis acetabulum (caput obliquum) and
holds the insertion of the tibial tuberosity by means of the patellar
ligament. This muscle is classified into muscle type 1.3
ii. NPRStus Lateralis muscle
This muscle type is a type II muscle that is on the lateral side
which holds attachments to the ventrolateral surface of the major
trochanter and the lateral labium, linea aspera femoris.
iii. Medial NPRS muscle
Attached to the labium medial linea aspera (lower two-thirds) and
includes type II muscles.3

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 iv. NPRStus intermedius muscle
Attachment to the ventro-lateral surface of the corpus femoris is
also a type II muscle.3

b. Knee Flexor Muscles (Hamstrings)

Hamstringsis a hamstring muscle that functions as a knee flexor and
hip extensor. In general, the hamstring is a type II muscle fiber muscle.
The hamstring is divided into three muscles namely:

Figure 3. Hamstring muscles 3

i. Biceps Femoris Muscle

Has two heads. Caput longum and breve, longum head originates
on the medial part of the tuber ichiadicum and semitendinosus muscle
while the breve head originates on the lateral labium linea aspera
femoris, inserts this muscle on the capitulum of the fibula.
ii. Semitendinosus muscle
This muscle originates on the medial part of the tuber ichiadicum
and inserts on the medial surface of the proximal end of the tibia.
iii.Semimembranosus muscle
Attached to the lateral pars of the ichiadicum tube descends
towards the medial side of the posterior femoral region and inserts on
the posterior surface of the medial condylus of the tibia.

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3. Ligaments
The passive stabilization function of the knee joint is carried out by
the ligaments. The ligaments in the knee joint are the cruciate ligaments
which are divided into two, namely the anterior cruciate ligament and the
posterior cruciate ligament. The collateral ligaments are also divided into
two parts, namely the medial collateral ligaments and the lateral collateral
ligaments
The cruciate ligament is the strongest ligament in the knee joint.
The cruciate ligaments are named because they cross one another. These
ligaments are at the front and back according to the attachment to the tibia.
The function of this ligament is to maintain movement at the knee joint,
limit extension movements and prevent rotational movements in extension
position, also maintain the forward and backward slide of the femur on the
tibia and as a stabilizer of the front and back of the knee joint.

Figure 4. Anatomy of a normal knee joint 3

a. Anterior cruciate ligament

The anterior cruciate ligament extends from the anterior part of the
intercondyloid fossa of the tibia attached to the lateral part of the

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 femoral condyle which functions to prevent the tibia from sliding
anteriorly towards the femur, resists external rotation of the tibia
during knee flexion, prevents knee hyperextension and helps when
rolling and gliding the knee joint.
b. Posterior cruciate ligament
The posterior cruciate ligament is a shorter ligament than the
anterior cruciate ligament. This fan-shaped ligament extends from the
posterior aspect of the tibia to the upper anterior portion of the tibial
intercondyloid fossa and is attached to the outer anterior aspect of the
medial condyle of the femur. This ligament functions to control the
slide of the tibia backward against the femur, preventing
hyperextension of the knee and maintaining stability of the knee joint.
c. Medial collateral ligament
The medial collateral ligament is the broad, flat ligament and its
membranous band lies on the medial side of the knee joint. This
ligament lies more posteriorly on the medial surface of the
tibiofemoral joint where it attaches above the medial epicondyle of the
femur below the adductor tubercle and downwards to the medial
condyle of the tibia and to the medial meniscus. This ligament is often
injured and its function is to maintain extension and prevent outward
movement
d. Lateral collateral ligaments
The lateral collateral ligaments are strong and attach above the
epicondyle of the femur and below the outer surface of the head of the
fibula. The function of this ligament is to control extension and prevent
medial movement. In knee flexion this ligament protects the lateral
side of the knee

4. Joint Capsule
The bones that form joints are connected to one another by a sheath
called the capsule articularis as a sheath that surrounds the joint surfaces
and tightly wraps the joint space between the bones. The outer layer of the

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 articular capsule (lamina fibrosa) is one of the important structures that
binds the bones forming joints. The fibrous lamina can withstand great
strain. The inner layer of the articular capsule (lamina synovial) is formed
by the synovial membrane which secretes synovial fluid (synovia) into the
joint space. The articular ends of the bone become enlarged and have a
thin but dense outer layer of bone (compacta), within which there is a
network of spongiosa bone. This knee joint capsule includes fibrous tissue
which is vascular so that if an injury is difficult the healing process
a. Articular cartilage/cartilage
Most adult joints are of the hyaline cartilage type and are the
vascular, alymphatic, and aneural tissues that cover the joint surfaces
of the long bones. Attached to the subchondral bone. The function of
cartilage is to cushion the bony covering in synovial joints, which
allows:3,8
- Withstanding pressure on the joint surface.
- Transmits and distributes increased loads.
- Maintains contact with minimal frictional resistance.
b. Exchange
Bursa is a bag filled with fluid that functions to prevent direct
friction, maybe muscle to muscle, muscle to bone and muscle to skin.
There are several bursae found in the knee joint, including: (1)
popliteus bursa (2) suprapatellaris bursa (3) infrapatellar bursa (4)
prepatellar subcutaneous bursa (5) subpatellaris bursa.

5. Meniscus
The meniscus is a soft tissue, the meniscus in the knee joint is the
lateral meniscus. The functions of the meniscus are (1) spreading the load
(2) shock absorbers (3) facilitating rotational movements (4) reducing
movement and stabilizers. Each pressure will be absorbed by the meniscus
and passed on to a joint.

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 Figure 5. Anatomy of the normal knee joint and OA6

C. Epidemiology

Osteoarthritis is a major cause of joint disability and is listed in the top

ten list of world diseases issued by the World Health Organization
(WHO). Epidemiological factors that increase the risk of knee OA include
joint injuries, joint overuse, and obesity. Joint injuries that occur at the age
of over 35 years are more at risk of causing OA than injuries at a young
age

Osteoarthritis accounts for most forms of arthritis and is a major cause

of disability in the elderly. OA is a major cause of burden to patients,
health care providers, and society. WHO reports that 40% of the world's
elderly population will suffer from OA, of which 80% have limited joint
motion. This disease usually occurs at the age of over 70 years. It can
occur in both men and women, but men can be affected at a younger age.
The prevalence of osteoarthritis in Indonesia is quite high, namely 5% at
age > 40 years, 30% at age 40-60 years and 65% at age > 61 years. Based
on a study conducted in rural Central Java, the prevalence for OA reached
52% in men and women between the ages of 40-60 years where 15.5% in
men and 12.7% in women9,10

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D. Etiology
Until now, the exact cause of knee OA is not known, but there are several
risk factors associated with knee osteoarthritis.
1. Age
The most important risk factor for OA is age, usually from young
adults to the elderly, but often over 50 years of age. With increasing age
there will be a decrease in cartilage volume, proteoglycan content,
cartilage vascularization, and cartilage perfusion. These changes can cause
characteristic changes that can be found on radiology, including thinning
of the joint space, and the appearance of ostheocytes. The prevalence and
severity of OA will increase with age, but OA does not only occur as a
result of increasing age, but can also occur due to changes in joint
cartilage.
2. Gender
The prevalence of OA is higher in women compared to men,
3.2% : 3%. This is associated with changes in postmenopausal women's
hormones
3. Hereditary Factor
Mutations in the procollagen gene or other structural genes for
joint cartilage elements such as collagen and proteoglycans play a role in
the emergence of a familial tendency in OA.8
4. Obesity
Obesity is a modifiable risk factor for OA. Obesity increases the
mechanical stress on the joints on which the body rests. This is closely
related to OA in the knees and in the lowest part of the hip. A study
evaluating the association between body mass index (BMI) over 14 years
and knee pain at 15 years in 594 women found that a high BMI at 1 year
and a significant increase in BMI over 15 years were predictors of knee
pain overall. bilateral at year 15.8
5. traumatized

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 Hip joint injury will cause reticular changes in the joint so that it
has an impact on the incidence of OA disease. In addition, heavy work
will determine the severity of OA experienced

6. Physical Activity
Heavy physical activity/weight bearing such as standing for a long
time (2 hours or more per day), walking long distances (2 hours or more
per day), lifting heavy objects (10 kg – 50 kg for 10 or more times per
week), pushing heavy objects (10 kg – 50 kg for 10 or more times per
week), going up and down stairs every day are risk factors for knee OA.

E. Clinical Signs and Symptoms

Symptoms that are commonly complained of by patients include: 1,8,11
1. Joint pain: This complaint is the main complaint that often brings patients
to the doctor. Pain usually increases with movement or certain activities and
slightly relieved by rest. Certain movements sometimes cause more intense
pain than other movements.
2. Barriers to joint movement: this disorder usually gets worse slowly in line
with increasing pain.
3. Stiff in the morning: in some patients, joint pain or stiffness may occur
after immobility, such as sitting in a chair or car for a long time or even after
waking up (for < 30 minutes).
4. Crepitation: a grinding (sometimes audible) feeling in the affected joint.
5. Joint enlargement (deformity): the patient may indicate that one of his
joints (often seen in the knee or hand) is slowly enlarging.
6. Gait change: almost all patients with OA ankle, heel, knee or hip develop a
limp and is a symptom that bothers the patient.
7. Other muscle pain of the musculoskeletal system.
8. Fatigue.

F. Diagnosis
The diagnosis of OA is established by history taking, physical examination
of the affected joint, checking for swelling and measuring the limits of joint

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 movement. X-rays, MRI, blood tests, and joint fluid analysis are recommended
as additional examinations to get a more detailed picture.
The American College of Rheumatology(ACR)compiled the diagnostic
criteria for idiopathic knee OA based on clinical and radiological examinations
as follows:

Table 1. Diagnostic criteria for knee OA according to ACR4

Clinical and
Clinical and Laboratory Clinical
radiology
 Knee pain + at least 5 of  Knee pain + at least  Knee pain + at least
the following 9: 1 of 3 of the 3 of the following
- Age > 50 years following: 6:
- Stiffness<30 minutes - Age > 50 years - Age > 50 years
- Crepitation - Stiffness<30 - Stiffness<30
- Pain on the bone minutes minutes
- Bone widening - Crepitus + - Crepitation
- Not warm to touch osteophytes - Pain on the bone
- LEDs <40mm/hr - Bone
- Rheumatoid enlargement
factor<1:40 - Not warm to
- Synovial fluid: clear, touch
viscous, leukocytes
<2000/mm3
Physical examination

Complaints that arise are then confirmed by physical examination which

shows joint enlargement, crepitations during active movement, muscle
weakness and joint instability. Examinations that can be carried out include:
local examination of the knee joint to assess signs of OA (Figure 6),
examination of the range of motion (ROM) of the knee joint (Figure 7).

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 Figure 6. Local examination of the knee joint 8
(a) Fluctuation test to see if there is fluid in the knee; (b) Palpation of the
lateral line of the joint in a patient with knee OA.
Figure 7. Knee Joint ROM 8

Flexion and extension. Internal and external rotation cannot be performed

during extension. In 90° of knee flexion with the lower leg hanging freely, the
knee exhibits a ROM from 10◦ in internal rotation to 25◦ in external rotation.

Provocation tests that can be done to check the knee joint:

a. McMurray test
This test is an examination to reveal meniscal lesions. In this test,
the patient lies on his back with one hand holding the examiner's heel
and the other hand holding the knee. The leg is then bent at the knee
joint. The lower limb exrotates/endrotates and is slowly extended. If
you hear a "click" sound or you can feel it when the knee is

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 straightened, then the medial meniscus or its posterior part may be torn.

Figure 8. McMurray Examination14

b. Anterior Drawer Test

This is a test to detect rupture of the anterior cruciate ligament of
the knee. The patient must be in a supine position with the hips flexed
45˚, knees flexed 90˚ and both feet parallel. You do this by moving the
tibia upward, there will be a hyperextension movement of the knee joint
and the knee joint will feel loose. The examiner's position is in front of
the patient's feet. If pushed more than normal (> 5 mm), it means a
positive drawer test

Figure 9. Anterior Drawer Test Examination 14

c. Posterior Drawer Test

Posterior Drawer Testthe same as the Anterior Drawer Test, only
holding the tibia and then pushing it backwards

Figure 10. Examination of the Posterior Drawer Test 14

d. Lachman test
Lachman testperformed by placing the knee in a flexed position at

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 approximately 30°, with the leg externally rotated. One hand of the
examination stabilizes the lower leg by holding the end or distal end of
the upper leg, and the other hand holds the proximal part of the tibia,
then tries to move it anteriorly. The Lachman Test serves to detect the
presence of anterior cruciate ligament lesions

Figure 11. Lachman Examination14

e. Appley Compression Test

This test is done to determine knee pain caused by a torn
meniscus. The patient is in a lying prone position and the lower leg is
bent at the knee joint and then pressure is placed on the patient's heel.
The emphasis is continued while turning the leg inward (endorotation)
and outward (exrotation). If the patient feels pain on the medial or
lateral side of the knee joint line, then the medial and lateral meniscus
lesions are very likely to exist.

Figure 12. Examination of the Appley Compression Test 12

f. Appley Distraction Test

This test is performed to differentiate meniscus or ligament
lesions in the knee joint. This inspection is a continuation of the
Appley Comppression Test. Distraction the knee joint while turning

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 the lower leg in and out and fix it. If there is pain in the exorrotation
and endorotation distractions, then this is caused by a lesion in the
ligament

Figure 13. Examination of the Appley Distraction Test 14

g. Test for Medial Stability

This test is to assess the instability of the medial collateral
ligament. The patient lies supine with the knees fully extended. Grasp
the lower leg with one hand placed on the posterior lateral knee and
force the distal lower leg laterally. Create valgus forces on the knee
and pressure on the medial collateral ligament. The maneuver is
performed at 0° and 30° knee flexion. Positive test if pain and/or
increased separation at the medial joint line

Figure 14. Test for Medial Stability 12

h. Test for lateral stability

This test is to assess the instability of the lateral collateral
ligament. The patient is in a supine supine position with the knee fully
extended. Grasp the lower leg with one hand placed on the posterior

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 medial knee while forcing the distal lower leg medially. Create varus
on the knee and stress on the lateral collateral ligaments. The maneuver
is performed at 0° and 30° knee flexion. The test is positive if there is
pain and/or increased space at the lateral joint line

Figure 15. Test for lateral stability12

Supporting investigation
1. Radiological Examination
A simple investigation that is often performed in OA cases is a
radiological examination of the AP/lateral genu in a standing position.
Typical features of knee OA are the presence of osteophytes & joint space
narrowing. 1,15 The degree of joint damage is based on radiological
features based on Kellgren & Lawrence criteria. 16

(A) (B)

(C) (d)

Figure 16. Kellgren and Lawrence criteria14

Grade 0: Normal radiology.

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 Grade 1: Doubtful osteophytes, normal joint appearance
Grade 2: Osteophytes are clear, joint space is good
Grade 3: Moderate and multiple osteophytes, joint space narrowing,
moderate sclerosis and possibly bony contour deformity.
Grade 4: Large osteophytes, marked joint space narrowing,
subchondral sclerosis and marked bony contour deformity.

G. MANAGEMENT
Osteoarthritis is an incurable condition. Handling is carried out aims to
reduce symptoms so that sufferers can continue their activities and live a
normal life. Symptoms of this condition can sometimes decrease slowly over
time.4,12,14

Management of patients with OA in the form of pharmacological and non-

pharmacological therapy, and medical rehabilitation, namely: 1,4,8,13,14,17

a. Pharmacological therapy
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- Intra-articular steroids
- Surgical therapy
- malalignment, knee valgus–varus deformity
- Osteotomy
- Arthroplastytotal joint
b. Non-pharmacological therapy
- Education and information
- Physical therapy and rehabilitation
- Weight loss
c. Medical rehabilitation in OA. The goals of medical rehabilitation in
general:
- Reducing pain
- Fixed range of motion (ROM)
- Repair function

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 - Improve quality of life

Management of medical rehabilitation in patients with knee OA includes:

1. KFR specialist
The doctor who performs the KFR examination, makes a diagnosis and
determines a medical rehabilitation program.
2. Physiotherapy
a. Cold Therapy
Cold therapy is used to improve blood circulation, reduce
inflammation, reduce muscle spasms and joint stiffness so as to reduce
pain. Can also use compressed ice on painful joints. Cold therapy
techniques, namely ice massage by rubbing ice directly on the treated
area for 5-7 minutes, ice compresses for 15-20 minutes, cold
compresses (vapocoolant spray) for example with chlorethyl spray,
especially for muscle spasms and MTPS (Myofascial Trigger Point
Syndrome). ).12,14
b. Heat Therapy
Heat therapy can be divided into 2 types, namely superficial heat
therapy and deep heat therapy. Superficial heat therapy, namely heat
only affects the cutis or subcutis tissue (hot packs, infrared, warm water
compresses, paraffin baths). Deep heat therapy, heat can penetrate
deeper into the tissues, to the muscles, bones and joints
1) Microwave diathermy(MWD)
Is a therapy using a wavelength between infrared waves
and short wave diathermic. The heat obtained from these waves
can be used to reduce pain. Diathermy waves are obtained by
heating a device called a magnetron. The output is transmitted to a
small channel and microwaves are emitted with a frequency of
2,450 cycles/second with a wavelength of 12.25 cm. This therapy
is suitable for pain, bacterial infections, and abscesses. The benefit
of this therapy is to increase the body's defense system and help
relaxation

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 2) Short wave diathermy(SWD)
It is a therapy using electric current with a frequency of
27,120,000 cycles/second with a wavelength of 11 meters. The
application method used is the condenser field method and cable
method. This method is suitable for use to treat inflammation of
shoulder joint pain, elbow joint, cervical degeneration, OA,
ligament sprains, low back pain, pain in the heel (plantar fascitis)
and sinusitis.

3) Ultra sound diathermy(USD).

Is a therapy using sound waves with a frequency of
500,000 to 3,000,000 cycles/second. Ultra sound is produced by
the vibrations of certain crystals. In the early stages, the ultrasound
application is carried out for 3 to 4 minutes, while in the advanced
stages, it is carried out for 6 to 8 minutes. This therapy is suitable
for elbow inflammation (tennis elbow), plantar pain (plantar
fascitis), muscle and ligament shortening, tendon inflammation,
ligament sprains, and chronic wounds. The benefit of this therapy
is to relieve pain and speed up wound healing. In the case of OA
USD (ultra sound diathermy) is used. 13,14

c. Electrical Therapy
TENS (Transcutaneous Electrical Nerve Stimulation)is a modality
used to reduce or eliminate pain. TENS is most often used for acute
pain and can also be used for chronic pain. The use of electrical therapy
is based on the gate control theory of Melzack and Wall, where large
diameter skin nerve fibers are stimulated by TENS and this stimulation
mechanism inhibits the transmission of pain stimuli to the spinal cord.
The next theory says that TENS works by stimulating endorphins and
endogenous opiates

d. Hydrotherapy
Hydrotherapy is a physical therapy by utilizing the physical
properties of water. Using water therapy helps someone heal. The

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 benefits of water in exercise therapy can be seen from the buoyancy
effect of water which will reduce the effect of gravity on any part of the
body so that there is a decrease in body activity and exercise is not
accompanied by pain. Warm water will reduce muscle spasms resulting
in overall relaxation and cause an increase in blood flow resulting in a
decrease in pain levels. Hydrotherapy is useful for giving exercise. The
buoyancy of the water will make the part or limb that is immersed
lighter so that the joint is easier to move. The warm water temperature
will help reduce pain, relax muscles and provide a sense of comfort

e. Muscle Strengthening Exercises

Exercise is known to improve and maintain joint movement,
strengthen muscles, increase static and dynamic resistance and
improve function. Strength training includes isometric, isotonic, and
isokinetic exercises. Isotonic means equal tension or weight. Tension
develops constantly as the length of the muscle changes. It involves
shortening of muscles and active contraction and relaxation of muscles
and occurs during movements such as walking, running, skipping etc.
In isometric contraction, the length of the muscle remains constant
while the tension varies. Here, tension develops in the muscles, but the
muscles don't shorten to move the object.Isokinetic pattern, in which
the muscle shortens. The isokinetic contraction of the load borne is not
the same and the speed in covering the track distance is average.13,14
3. Occupational Therapy
Occupational therapy includes exercises to coordinate activities of
daily living (AKS) to provide exercises to restore function so that patients
can return to their normal activities or work.
4. Prosthetic Orthotics
Prosthetic orthotics are used to restore function, prevent and correct
disabilities, support weight and support diseased limbs. In patients with
OA, it is usual to plan to use a knee brace or knee support.
5. Medical Social Officer
The aim is to resolve and solve social problems related to the patient's

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 illness, such as patient problems in the family and community
environment.
6. Psychology
An activity that aims to help patients who have problems in life or
problems with behavior and mental processes.

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