Joints & Joint Movements | Skeletal System 05 | Anatomy & Physiology

Summary

This video provides an in-depth overview of key joints and their movements essential for understanding human biomechanics, especially in sports. The shoulder, elbow, hip, wrist, knee, and ankle joints are explored, highlighting their structure and function. The video covers a variety of joint movements, including flexion, extension, hyperextension, dorsiflexion, plantar flexion, rotation, circumduction, and others, explaining their relevance and application in sports. Viewers are encouraged to practice and engage with their own body to reinforce the concepts, ultimately helping to better understand joint movements and their role in athletic performance.

Takeaways

• 😀 The shoulder joint is a ball and socket joint formed by the humerus, clavicle, and scapula.
• 😀 The elbow is a hinge joint made up of the humerus, radius, and ulna, allowing flexion and extension.
• 😀 The hip joint is also a ball and socket joint, formed by the femur and pelvis, allowing a wide range of movement.
• 😀 The wrist is classified as a condyloid joint, allowing flexion, extension, and other movements beyond simple hinge action.
• 😀 The knee joint is a classic hinge joint, primarily formed by the femur and tibia, with the patella offering protection.
• 😀 The ankle joint is another hinge joint, formed by the tibia, fibula, and tarsals, with flexion and extension movements.
• 😀 Flexion refers to decreasing the joint angle, while extension increases it. An example is elbow flexion and extension.
• 😀 Dorsiflexion and plantarflexion are specific to the ankle, where both upward and downward foot movements are classified as flexion.
• 😀 Hyperextension occurs when a joint extends past its normal range, like the elbow going beyond 180 degrees.
• 😀 Abduction is the movement of a limb away from the body's midline, while adduction brings it back towards the midline.
• 😀 Rotation involves pivoting around a fixed axis, whereas circumduction is the circular movement at a joint, like the shoulder or hip.

Q & A

What are the primary bones that form the shoulder joint?

The shoulder joint is formed by the humerus (upper arm), clavicle (collarbone), and scapula (shoulder blade).

How does the elbow joint differ from the shoulder joint in terms of structure?

The elbow is a hinge joint, formed by the humerus in the upper arm, and the radius and ulna in the forearm, allowing for bending and straightening motions.

What type of joint is the hip, and what bones are involved?

The hip is a ball-and-socket joint, with the femur (thigh bone) as the ball and the pelvis forming the socket.

Why is the wrist considered a condyloid joint rather than a pure hinge joint?

The wrist is classified as a condyloid joint because it allows not only flexion and extension but also other movements, unlike a hinge joint which only permits bending and straightening.

What is the function of the patella in the knee joint?

The patella, or kneecap, sits on top of the knee joint and primarily serves to protect the joint and improve the efficiency of leg movement.

What are dorsiflexion and plantar flexion at the ankle, and how do they differ?

Dorsiflexion refers to the movement where the toes point upwards, decreasing the angle between the foot and the tibia, while plantar flexion refers to pointing the toes downward, also decreasing the joint angle but in the opposite direction.

What is hyperextension, and why is it not desirable in some joints like the knee?

Hyperextension occurs when the joint angle exceeds 180 degrees. It is undesirable in joints like the knee because it can damage ligaments and other structures.

What is the difference between abduction and adduction?

Abduction refers to moving a limb away from the body's midline, while adduction refers to moving a limb toward the body's midline.

What is the movement of circumduction, and which joints allow it?

Circumduction involves moving the distal end of a limb in a circular motion, which is possible at ball-and-socket joints like the shoulder and hip.

How are horizontal flexion and horizontal extension different from regular flexion and extension?

Horizontal flexion and extension occur in the horizontal plane and involve movements across the body, such as bringing the arm toward or away from the torso, whereas regular flexion and extension happen in the sagittal plane, affecting joint angles in a forward or backward direction.