Types of joints:
Ball-and-socket joint: Consists of a bone with a globular or slightly egg-shaped head that articulates with the cup-shaped cavity of another bone. Such a joint allows a wider range of motion than does any other kind, permitting movements in all planes, as well as rotational movement around a central axis. The hip and shoulder contain joints of this type.
Condyloid joint: The ovoid condyle of one bone fits into the elliptical cavity of another bone, as in the joints between the metacarpals (bones of the palm) and phalanges (bones of the fingers and toes). This type of joint permits a variety of movements in different planes; rotational movement, however, is not possible.
Gliding joints: The articulating surfaces are nearly flat or slightly curved. These joints allow sliding or back-and-forth motion and twisting movements. Most of the joints within the wrist and ankle, as well as those between the articular processes of adjacent vertebrae, belong to this group. The sacroiliac joints and the joints formed by ribs 2 though 7 connecting with the sternum are also gliding joints.
Hinge joint: The convex surface of one bone fits into the concave surface of another, as in the elbow and the joints of the phalanges. Such a joint resembles the hinge of a door in that it permits movement in one plane only.
Pivot Joint: The cylindrical surface of one bone rotates within a ring formed of bone and fibrous tissue of a ligament. Movement at such a joint is limited to rotation around a central axis. The joint between the proximal ends of the radius and the ulna, where the head of the radius rotates in a ring formed by the radial notch of the ulna and a ligament (annular ligament), is of this type. Similarly, a pivot joint functions in the neck as the heard turns from side to side. In this case, the ring formed by a ligament (transverse ligament) and the anterior arch of the atlas rotates around the dens of the axis.
Saddle joint: Forms between bones whose articulating surfaces have both concave and convex regions. The surface of one bone fits the complementary surface of the other. This physical relationship permits a variety of movements, mainly in two planes, as in the case of the joint between the carpal (trapezium) and the metacarpal of the thumb.
Types of joints movements:
Flexion: Bending parts at a joint so that the angle between them decreases and the parts come closer together (bending the lower limb at the knee).
Extension: Straightening parts at a joint so that the angle between them increases and the parts move farther apart (straightening the lower limb at the knee).
Hyperextension: Excess extension of the parts at a joint, beyond the anatomical position (bending the head back beyond the upright position).
Dorsiflexion: Bending the foot at the ankle toward the shin (bending the foot upward).
Plantar flexion: Bending the foot at the ankle toward the sole (bending the foot downward).
Abduction: Moving a part away from the midline (lifting the upper limb horizontally to form a right angle with he side of the body).
Adduction: Moving a part toward the midline (returning the upper limb from the horizontal position to the side of the body).
Rotation: Moving a part around an axis (twisting the head from side to side). Medial rotation involves movement toward the midline, whereas lateral rotation involves movement in the opposite direction.
Circumduction: Moving a part so that its end follows a circular path (moving the finger in a circular motion without moving the hand).
Supination: Turning the hand so the palm is upward or facing anteriorly (in anatomical position).
Pronation: Turning the hand so the palm is downward or facing posteriorly (in anatomical position).
Eversion: Turning the foot so the sole faces laterally.
Inversion: Turning the foot so the sole faces medially.
Protraction: Moving a part forward (thrusting the chin forward).
Retraction: Moving a part backward (pulling the chin backward).
Elevation: Raising a part (shrugging the shoulders).
Depression: Lowering a part (drooping the shoulders).
Major joints of the body (usually involved with SMA):
| Joint | Type of joint | Type of movement |
| Shoulder | Ball-and-socket | Flexion, extension, adduction, abduction, rotation, circumduction |
| Elbow | Hinge | Flexion, extension |
| Proximal radioulnar | Pivot | Rotation |
| Wrist | Condyloid | Flexion, extension, adduction, abduction, circumduction |
| Carpometacarpal 1 | Saddle | Flexion, extension, adduction, abduction |
| Carpometacarpal 2-5 | Condyloid | Flexion, extension, adduction, abduction |
| Metacarpophalangeal | Condyloid | Flexion, extension, adduction, abduction |
| Interphalangeal | Hinge | Flexion, extension |
| Hip | Ball-and-socket | Flexion, extension, adduction, abduction, rotation, circumduction |
| Tibiofemoral (knee) | modified hinge | Flexion, extension, slight rotation when flexed |
| Ankle | Hinge | Dorsiflexion, plantar flexion, slight circumduction |
| Metatarsophalangeal | Condyloid | Flexion, extension, adduction, abduction |
Definitions
of
joints:
Proximal
radioulnar:
The
joint
near
the
radius
and
ulnar
bones.
Carpometacarpal
1:
The
joint
between
the
wrist
bone
and
the
first
palm
bone.
Carpometacarpal
2-5:
The
joint
between
the
wrist
bone
and
the
2nd
through
the
5th
palm
bone.
Metacarpophalangeal:
The
joints
between
the
palm
bones
of
the
hand
and
the
finger
and
toe
bones.
Interphalangeal:
The
joints
between
the
bones
of
the
fingers
and
toes.
Tibiofemoral:
The
joint
in
the
knee
between
the
tibial
and
the
femoral
bones.
Metatarsophalangeal:
The
joint
in
between
the
palm
of
the
foot
and
the
toes.
