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 is the simplest element. An atom of hydrogen consists of only one proton and one electron. It's also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth-it's always combined with other elements.ater, for example, is a combination of hydrogen and oxygen (H 2 O). Hydrogen is also found in many organic compounds, notably the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane.