This text explores postures and balance of the human body. It describes how different stances affect balance, particularly under conditions like uneven weight distribution and external forces like the wind. It also examines the mechanics of pulling versus pushing, focusing on specific muscles and how leverage affects strength.
On the Human Figure.
There is an uncommon posture when the shoulder leans towards the side where the foot does not bear the body's weight: then the entire balance of the figure relies on the hip and lower back. See figure A from plate XVII.
A person stands in an uncertain posture when weight is equally on both feet: this is the usual position of those languishing from illness, those tired from excessive work, or those burdened by decrepit old age. It is also common among children who lack sure posture. See figure B on the same plate.
Someone walking against a strong wind does not adhere to the rules of balance for keeping their body upright over its center of support: the more they lean forward, the stronger the wind blows. Same plate, fig. C.
A person has more strength to pull than to push, because when pulling, the arm muscles are engaged, which are only strong for pulling, not pushing. This also relates to the muscle AB (plate XVIII, figure below) which flexes the arm, being stronger and further from the elbow's pivot, above the arm, than the muscle DE below the arm, extending it and being weaker, as it's closer to the center of the same elbow C. This movement comes from a simple force of the arms, and a compound force, when arm strength is combined with the body's weight, as illustrated in the following plate's example.