A: Radius
B: Ulna
C: Carpals (wrist)
D: Humerus

1: Synovial joint: Pivot.
It is situated between the radius and the ulna. The only movement allowed is rotation. This is characteristic of the pivot joint. The head of the radius rotates within a ringlike ligament secured to the ulna.
2: Synovial joint: Condyloid (= ellipsoidal).
It is situated between the radius and the carpals. The movements allowed are flexion/extension, adduction/abduction and circumduction. Both saddle and condyloid (= ellipsoidal) joints allow such movements. However the shapes of its articular surfaces classify it as a condyloid joint: one bone's oval convex surface fits into the oval concavity of the adjacent bone.