Sem biomech-6 physiotherapy bachelor year.pdf

Physiotherapy lectures last year

2. Definition
Joint is the articulation between any of
rigid component parts of the skeleton
whether bones or cartilage by different
tissues.

3. Functions of the joints:
Allowing movements of body segments by
providing the bones with a mean of moving.

Providing stability without interfering with the
desired motion.

The function of the joints depends upon the
shape of the contours of the contacting
surfaces and how well it fits together.

4. Cartilaginous Fibrous
Synovial
Synarthroses diarthroses Amphiarthroses
JOINT CLASSIFICATION ACCORDING
TO MOTION CAPABILITIES:

5. JOINT CLASSIFICATION ACCORDING
TO MOTION CAPABILITIES:
Immovable Joints, Synarthroses:

These fibrous joints can attenuate force (absorb shock) but
permit little or no movement of the articulating bones.

Sutures: In these joints, the irregularly grooved articulating
bone sheets mate closely and are tightly connected by fibers
that are continuous with the periosteum.
The sutures of the skull.

Syndesmoses: In these joints, dense fibrous tissue binds the
bones together, permitting extremely limited movement.
coracoacromial, mid radioulnar, mid tibiofibular, and inferior
tibiofibular joints.

6. Synarthroses

7. Slightly Movable Joints, Amphiarthroses:

These cartilaginous joints attenuate applied forces and
permit more motion of the adjacent bones than
synarthrodial joints.

Synchondroses: In these joints, the articulating bones
are held together by a thin layer of hyaline cartilage.

the sternocostal joints

Symphyses: In these joints, a disc of fibrocartilage
separates the bones.
the vertebral joints and the pubic symphysis



JOINT CLASSIFICATION ACCORDING
TO MOTION CAPABILITIES:

8. Amphiarthroses

9. Freely Movable Joints,
Diarthroses or synovial:

At these joints, the
articulating bone surfaces
are covered with articular
cartilage, an articular
capsule surrounds the joint,
and a synovial membrane
lining the interior of the joint
capsule secretes a lubricant
known as synovial fluid.


JOINT CLASSIFICATION ACCORDING
TO MOTION CAPABILITIES:

10. Hinge
Pivot
Ball and
Socket
Ellipsoid
Saddle
Gliding
Types of synovial joints

13. Synovial joints vary widely in structure and movement
capabilities. They are commonly categorized according to
the number of axes of rotation present. Joints that allow
motion around one, two, and three axes of rotation are
referred to respectively as uniaxial, biaxial, and triaxial
joints.

 A few joints where only limited motion is permitted in any
direction are termed nonaxial joints.

 Joint motion capabilities are also sometimes described in
terms of degrees of freedom (df ), or the number of planes
in which the joint allows motion. A uniaxial joint has one df,
a biaxial joint has two df, and a triaxial joint has three df.

Synovial Joints

14. Bursae:
Are small capsules, lined with
synovial membranes and filled
with synovial fluid, that cushion
the structures they separate.
Most bursae separate tendons
from bone, reducing the friction
on the tendons during joint
motion.
Some bursae, as the olecranon
bursa of the elbow, separate
bone from skin.

15. Tendon sheaths:
 are double-layered
synovial structures that
surround tendons
positioned in close
association with bones.

Many of the long muscle
tendons crossing the wrist
and finger joints are
protected by tendon
sheaths.

16. Articular Cartilage
In the human body, a special type of dense, white connective
tissue known as articular cartilage provides a protective
lubrication.

A 1- to 5-mm-thick protective layer of this avascular, non-
innervated material coats the ends of bones articulating at
diarthrodial joints.

Articular cartilage serves two important purposes:
It resists compression and spreads loads at the joint over a
wide area so that the amount of stress at any contact point
between the bones is reduced.
It allows movement of the articulating bones at the joint with
minimal friction and wear.

17. Articular Cartilage
It is a soft, porous,
and permeable tissue
that is hydrated.
It consists of
specialized cells
called chondrocytes
embedded in a matrix
of collagen fibers,
proteoglycans, and
non-collagenous
proteins.

19. Articular Cartilage
Nourishment comes by diffusion from synovial
fluid with loading and unloading of the joint.

When joint loading occurs at a low rate, the solid
components of the cartilage matrix resist the load.
When loading is faster, however, it is the fluid
within the matrix that primarily sustains the
pressure.

Unfortunately, once damaged, articular cartilage
has little to no ability to heal or regenerate on its
own.

20. Articular Fibrocartilage
At some joints, articular
fibrocartilage, in the form of
either;
a fibrocartilaginous disc
or partial discs known as
menisci, is also present
between the articulating bones

21. Articular Fibrocartilage
The roles of articular fibrocartilage may include:

Distribution of loads over the joint surfaces.
Improvement of the fit of the articulating surfaces.
Limitation of translation or slip of one bone with
respect to another.
Protection of the periphery of the articulation.
Retention of joint lubrication.
Shock absorption.

22. JOINT STABILITY
The stability of an articulation is its ability to
resist dislocation. Specifically, it is the ability
to resist the displacement of one bone end
with respect to another while preventing
injury to the ligaments, muscles, and muscle
tendons surrounding the joint.

23. Factors influencing Joint Stability:
Shape of the Articulating Bone Surfaces

Although most joints have reciprocally shaped
articulating surfaces, these surfaces are not
symmetrical, and there is typically one position of
best fit in which the area of contact is maximum,
the close-packed position with greatest stability.

Any movement of the bones at the joint away from
the close-packed position results in a loose-
packed position, with reduction of the area of
contact.

25. Arrangement of Ligaments and Muscles

At joints such as the knee and the shoulder, in which
the bone configuration is not particularly stable, the
tension in ligaments and muscles contributes
significantly to joint stability by helping to hold the
articulating bone ends together.

If these tissues are weak from disuse or lax from being
overstretched, the stability of the joint is reduced.
Strong ligaments and muscles often increase joint
stability.
Factors influencing Joint Stability:

26. Factors influencing Joint Stability:
Other Connective
Tissues

White fibrous connective
tissue known as fascia
surrounds muscles and
the bundles of muscle
fibers within muscles,
providing protection and
support.

28. Relationship Between
Physiological & Accessory Motion
Physiological motion (Osteokinematics):
Result of concentric or eccentric active muscle
contractions.
Bones moving about an axis or through flexion,
extension, abduction, adduction or rotation

Accessory Motion (Arthrokinematics):
Motion of articular surfaces relative to one another.
 Generally associated with physiological movement.
As, Roll, Slide and Spin.