The subtalar joint contributes to 10% of dorsiflexion of the ankle. There are three articulating facets between the talus and the calcaneus, delineated as the anterior, middle and posterior facets. The sustentaculum tali forms the floor of middle facet, and the anterior facet articulates with the head of the talus, and sits lateral and congruent to the middle facet.
The most abundant element on Earth is oxygen, but the most abundant element in the entire universe is hydrogen. On Earth, oxygen makes up approximately 47 percent of the Earth's mass and is found both in Earth's atmosphere and crust. Continue Reading.
Hydrogen: the essentials. Note that while hydrogen is normally shown at the top of the Group 1 elements in the periodic table, the term alkaline metal refers to the Group 1 elements from lithium downwards and not hydrogen. Hydrogen is the lightest element. It is by far the most abundant element in the universe and makes up about about 90% of the universe by weight. It is also the most abundant element in the earth's sun. Hydrogen as water (H 2 O) is absolutely essential to life and it is present in all organic compounds.