Synonyms
Joint head, socket, joint mobility Medical: Articulatio
- Hip joint
- Shoulder joint and
- Basic Finger Joints
Ball joints have an infinite number of axes of motion, but from a functional point of view three main axes are defined, so that these are joints with three degrees of freedom. This is done around a sagittal axis:
- Abduction (abduction) and the
- Approach (adduction), around the transverse axis the
- Bending (flexion) and the
- (extension) and around the longitudinal axis the
- Inrolling (internal rotation) and
- External rolling (external rotation)
A nut joint is a joint in which the socket extends beyond the equator of the joint head. Egg joints have elliptical joint bodies with two joint bodies standing perpendicular to each other.
Two degrees of freedom are possible and thus four main movements are possible. Typical egg joints are the wrist close to the body and the head joints between the back of the head and the first cervical vertebra (atlas). Hinge joints, wheel joints or trunnion joints are also called roller joints.
In hinge joints, a cylindrical joint body engages in the groove-shaped recess of a hollow cylindrical joint body. Hinge joints have only one degree of freedom. Typical hinge joints are: In wheel or trunnion joints, a cylindrical skeletal element is connected to the corresponding part of a hollow cylinder and a ring or cross band.
Here, only rotary movements around an axis are possible. Saddle joints have saddle-shaped curved joint surfaces whose two main axes of movement are perpendicular to each other. Rotational movements are only possible when both joint surfaces are out of contact.
The thumb saddle joint is a typical saddle joint. Plane joints have nearly plane joint surfaces and allow shifting and rotating movements in one plane. The small vertebral joints belong to the plane joints.
Taut joints (amphiarthroses) are joints whose mobility is severely restricted by tight ligaments. These include the tibiofibular joint (tibiofibular joint) and the sacroiliac joint (sacroiliac joint).
- Elbow joint and the
- Upper ankle joint
