Flashcards on Convex Concave Rule in Arthrokinematics
Convex Concave Rule in Arthrokinematics: Student's Guide
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Arthrokinematics of Joints
8 cards
Card 1
Question: What do the terms 'convex' and 'concave' surfaces mean in the context of joints?
Answer: A concave surface is 'caved in' (as shown on the left), while a convex surface bulges outward. These terms are used to differentiate joint surfaces fo
Card 2
Question: What is the purpose of the convex-concave rule?
Answer: To understand arthrokinematics – specifically, how joint surfaces slide and move relative to each other (e.g., in the shoulder and elbow).
Card 3
Question: How do the bone and joint surface move when a concave surface is moving?
Answer: When a concave surface moves, the joint surface and the bone move in the same direction.
Card 4
Question: Provide an example where a concave surface is moving and describe the direction of movement.
Answer: In the elbow, the ulna is concave and the humerus is convex. When the concave ulna moves, both the joint surface and the bone move in the same directi
Card 5
Question: How do the bone and joint surface move when a convex surface is moving?
Answer: When a convex surface moves, the bone moves in the opposite direction to the joint surface.
Card 6
Question: Provide an example where a convex surface is moving and describe the direction of movement.
Answer: In the shoulder, the convex humerus moves on the concave scapula. When the convex surface moves downward, the bone (humerus) moves in the opposite dir
Card 7
Question: What's an easy way to remember which surface is concave?
Answer: Think of a concave surface as being 'caved in' or 'hollowed out'.
Card 8
Question: Why is it important to know which surface (convex or concave) is moving?
Answer: Because it determines the relative direction of glide between the joint surface and the bone (either the same or opposite direction), which is crucial