The 6 Types of Joints - Human Anatomy for Artists

Summary

This Proko lesson delves into the six types of synovial joints crucial for artists: hinge, pivot, ball & socket, ellipsoid, saddle, and plane. It emphasizes their unique movements and positions, aiding in realistic pose creation and understanding body limitations. The lesson also introduces the spine's significance and assigns practical exercises for better comprehension, encouraging study and simplified drawing of these joints.

Takeaways

• 💡 The human skeleton's joints define the body's motion and its limitations, with a focus on synovial joints for artists due to their mobility.
• 🎯 Synovial joints are crucial for artists as they allow for movement, unlike fibrous and cartilaginous joints which are mostly immobile.
• 🔍 Importance of understanding synovial joints for accurate representation in art, such as the hinge joint's role in limiting foot movements.
• 🤸‍♂️ Six types of synovial joints are identified: Hinge, Pivot, Ball & Socket, Ellipsoid, Saddle, and Plane, each with unique movement capabilities.
• 📐 Hinge joints permit flexion and extension, exemplified by the elbow joint, which only allows movement in one direction.
• 🔄 Pivot joints enable rotation around a single axis, as seen in the radio-ulnar joint, allowing for pronation and supination of the forearm.
• 🏋️‍♂️ Ball & Socket joints offer the broadest range of motion, including flexion, extension, abduction, adduction, rotation, and circumduction, with examples being the shoulder and hip.
• 🛤️ Ellipsoid joints resemble ball & socket joints but restrict rotation, allowing movement on two axes, such as in the wrist.
• 🤲 Saddle joints, like the carpometacarpal joint of the thumb, feature a unique structure that allows for a combination of movements with slight rotation.
• 🛴 Plane joints, while less mobile, permit gliding or rotation and are often found in groups, like in the hand and foot.
• 📝 Assignments for the lesson include finding and studying the movement of these joints on oneself and drawing them in simplified forms for better understanding and application.

Q & A

What is the primary focus of this Proko lesson?

The primary focus of this Proko lesson is to teach about the types of synovial joints in the human body, which are important for artists to understand when drawing moving figures.

Why are synovial joints particularly important for artists?

Synovial joints are important for artists because they are the joints that allow movement, such as the shoulder and knee, and understanding them helps in accurately depicting motion and poses in art.

What types of joints are not considered important for artists in this context?

Fibrous and cartilaginous joints are not considered important for artists in this context, as they hardly move or do not move at all, unlike synovial joints.

How many types of synovial joints are there, and what are they?

There are six types of synovial joints: Hinge, Pivot, Ball & Socket, Ellipsoid, Saddle, and Plane.

What is the basic movement allowed by a hinge joint?

A hinge joint allows movement only on one axis, permitting flexion and extension, similar to the way a door opens and closes.

How does a pivot joint differ from a hinge joint in terms of movement?

A pivot joint allows rotation around one axis, but along the long axis of the bone, enabling movements like pronation and supination of the forearm.

What kind of movement does a ball & socket joint allow?

A ball & socket joint allows movement in all axes, including flexion, extension, abduction, adduction, rotation, and circumduction, providing the greatest range of motion.

What is unique about the ellipsoid joint compared to the ball & socket joint?

The ellipsoid joint is similar to a ball & socket joint but does not allow rotation due to its oval shape and ligaments, though it can still rotate on two axes.

How does the saddle joint differ in structure from other synovial joints?

The saddle joint has a unique structure where both bones have a concave and convex surface that fit together, allowing for a combination of movements including flexion, extension, abduction, adduction, circumduction, and slight rotation.

What is the main function of a plane joint?

A plane joint allows for gliding or rotation movements, typically found in groups such as the carpals of the hand and the tarsals of the foot.

What special assignment is given to the viewers of the lesson, and where should they post their work?

The viewers are assigned to find and study the movements of the synovial joints on themselves and to draw them as simple versions. They should post their drawings in the Facebook group at facebook.com/groups/anatomy4artists for critique.

What additional resources are available for viewers to enhance their understanding of anatomy?

Additional resources include a PDF ebook that visually defines all the anatomical terms, another PDF ebook classifying every joint in the body by type, and a 3D model of Robo Skelly, all available as premium features at proko.com/anatomy.