Convex-Concave Rule (and concave-convex rule)

Convex-Concave Rule (and concave-convex rule): These rules describe an arthrokinematic pattern that minimizes the inherent migration of the center of the axis of rotation of a joint, in the direction of arthrokinematic roll. Note, these rules were developed with the intent to aid in teaching, specifically to assist with “visualizing” joint motion. They were not intended to dictate the direction of joint mobilization or manipulation techniques (although they can aid in decision-making).

• The concave-convex rule implies that when a bone ending in a concave surface (e.g., the humeral head) is moving on a convex surface (e.g., the glenoid fossa), that glide will occur in the opposite direction of the roll.
• The convex-concave rule implies that when a bone ending in a convex surface (e.g., the mortise of the ankle) is moving on a concave surface (e.g., the dome of the talus), that glide will occur in the same direction as the roll.

For more information, we recommend the following publication: The convex-concave rules of arthrokinematics: flawed or perhaps just misinterpreted? (Hyperlink article title - https://mtitx.com/wp-content/uploads/2016/05/Journal-of-orthopaedic-and-Sports-Physical-Therapy-2012-Neumann.pdf )An example from this publication:

“…consider an adult-size humeral head with a circumference of 16 cm. A motion of 90° of GH joint abduction occurring purely due to a rolling motion (with no concurrent inferior slide at the articular surface) would theoretically cause the humeral head to roll upward on the glenoid about 4 cm. Clearly, a significant, concurrent inferior slide of the humeral head must occur. This offsetting slide is an essential component of GH joint abduction, especially considering that the adult subacromial space is only about 1 cm in height.”

Although, these rules are often attributed to Kaltenborn (2), their origin is likely decades older (1950s – 1960s) with references in publications by MacConaill, Maitland, Basmajian, and Steindler (3-6).

1. Neumann, D. A. (2012). The convex-concave rules of arthrokinematics: flawed or perhaps just misinterpreted?. journal of orthopaedic & sports physical therapy, 42(2), 53-55.
2. MA, M. (1964). JOINT MOVEMENT. Physiotherapy, 50, 359-367.
3. MacConaill, M. A. (1953). The movements of bones and joints: 5. The significance of shape. The Journal of bone and joint surgery. British volume, 35(2), 290-297.
4. Basmajian, J. V., & MacConaill, M. A. (1969). Muscles and movements: A basis for human kinesiology. Williams & Wilkins
5. Maitland GD. Peripheral Manipulation. 2nd ed. Boston, MA: Butterworths; 1977Steindler, A. (1955). Kinesiology of the human body under normal and pathological conditions. (No Title).
6. Steindler, A. (1955). Kinesiology of the human body under normal and pathological conditions. (No Title).