Outlines of human osteology / by F.O. Ward.

Frederick Oldfield Ward

Date:: 1876

Credit: Outlines of human osteology / by F.O. Ward. Source: Wellcome Collection.

364/392 page 344

$motive organs come at last to be exerted, on the one hand Lte TT'T ^'''^ ^ sitfor\w?f/ /•I'-T''*'* P^^'^^^^' the former tran- sition, into artificial conveyance; by the latter into ■ is f ^p^oial) a,Metic%ports. Inrnished with this usehil preliminary knowledge, we may next proceed (stiU m detail the comphcated actions of progression- and especially those by which its two most important mo'des- yiz., ^oalk^nc| and running, are performed; and for this purpose we shall constantly avail ourselves of the valuable experimental and theoretical investigations of W. and E Weber, to whose work (entitled MechaniJc der Mensch- referred ^^^^ already several times 416. The object, in walMng, is to keep the body moving at a rate as nearly as possible imiform, in aline as nearly as _ possible horizontal. In order to understand how this object is accomphshed, we must consider, first, the series ot movenients performed by the locomotive organs at each step,_ and the direction in which the force they exert is applied to the trunk; and secondly, the external forces which act on the body in walking, and concur with the ^^1*;^^'' ^^''^ production of the observed effect. 417. Each leg is planted on the ground during one step, and swings m the air during the next; so that, to trace Its entire action, we must follow it through two consecu- tive steps. As, however, one leg is in the act of swinging m the air, while the other is resting on the ground, the two together exemplify the whole series of movements in each single step. 418. The leg that we set forward in taking a step, advances at its upper extremity, by turning below on the planted foot, first at the ankle-joint, and afterwards on the ball of the great toe; in which advance the trunk, resting on its upper end, necessarily participates. During this action there is an instant when the direction of the limb (represented by a line drawn from the centre of the head of the femur to the centre of the surface which, for the time being, touches the ground) is exactly vertical ;— that IS to say, when the head of the advancing femur arrives directly over the planted foot. During the period which precedes this moment, the foot is in advance of the body, and the direction of the leg is from the trunk down- ward imd. forward; during the subsequent period, the foot$

Outlines of human osteology / by F.O. Ward.

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