Popliteus muscle assists in flexing the leg upon the thigh; when the leg is flexed, it will rotate the tibia inward. It is especially called into action at the beginning of the act of bending the knee, inasmuch as it produces the slight inward rotation of the tibia, which is essential in the early stage of this movement. When the knee is in full extension, the femur slightly medially rotates on the tibia to lock the knee joint in place. Popliteus is often referred to as the "Key" to unlocking the knee since it begins knee flexion by laterally rotating the femur
Tibia fusus cm (9 in.). These shells are large, spindle-shaped with moderately convex turns and an extremely long, thin and slightly curved siphonal canal. The basic color ranges from straw yellow to reddish-beige. The aperture is ovate and white inside, with 6 fingerlike growths on the outer lip. It is a fairly common species where it occurs, but because of its attractive appearance, it is highly sought after by shell collectors. Embryos develop into free-swimming planktonic marine larvae (trocophore) and later into juvenile veligers. Tibia fusus Tibia fusus, common name Spindle tibia or Shinbone Tibia Gastropod, is a species of large sea