Oblique Pull

“It is worthy of note that, owing to the oblique direction in which the muscles are commonly inserted into the bones, much of their force is lost so far as producing movement is concerned. Suppose the log of wood in the diagram to be raised by pulling on the rope in the direction a; it is clear at first that the rope will act at a great disadvantage; most of the pull transmitted by it will be exerted against the pivot on which the log hinges, and only a small fraction be available for elevating the latter. But the more the log is lifted, as for example into the position indicated by the dotted lines, the more useful will be the direction of the pull, and the more of it will be spend on the log and the less lost unavailingly in merely increasing the pressure at the hinge.” —Martin, 1917

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