Pivot joint in rotating an arm inward). When rotating the forearm, these movements are typically called pronation and supination. In the standard anatomical position, the forearms are supinated, which means that the palms are facing forward, and the thumbs are pointing away from the body. In contrast, a forearm in pronation would have the palm facing backward and the thumb would be closer to the body, pointing medially. Examples of a pivot joint include: In contrast, spherical joints (or ball and socket joints) such as the hip joint permit rotation and all other directional movement, while pivot joints only permit rotation. Pivot
Western saddle variations include the following: There are many variations of design and optional equipment elements that were influenced by geographic region, history, use and the body types of horses bred in a given area. Certain stylistic elements seen on some, but not all western saddles include: There are several different sizes of trees commonly found in saddles. Trees differ in the width of gullet and bars of the saddle, pitch of the bars (steep to flat, usually between an angle of 86 to 94 degrees with 90 being common), and length of the bars. The tree also influences the shape of