Applied anatomy and kinesiology; the mechanism of muscular movement . of grain is very similar, with a one-sided action when the objectis shouldered. Picking strawberries and weeding onions and othersmall plants, because of the stooping posture, give much work forthe extensors of trunk and limbs. Baggage men, expressmen, and men who haul lumber, stone andfreight of all kinds have to grasp, lift, and in general use the bodily INDUSTRIAL OCCUPATIONS 319 mechanisms just mentioned. Many other special examples willoccur to the reader. Lifting and reaching upward is seen in hanging clothes on aline.
Applied anatomy and kinesiology; the mechanism of muscular movement . of grain is very similar, with a one-sided action when the objectis shouldered. Picking strawberries and weeding onions and othersmall plants, because of the stooping posture, give much work forthe extensors of trunk and limbs. Baggage men, expressmen, and men who haul lumber, stone andfreight of all kinds have to grasp, lift, and in general use the bodily INDUSTRIAL OCCUPATIONS 319 mechanisms just mentioned. Many other special examples willoccur to the reader. Lifting and reaching upward is seen in hanging clothes on aline. Women with weak arms are especially likely to hollow theback and protrude the abdomen in this work, for reasons givenelsewhere. Carrying hod is work for the extensors of the trunk and lowerlimbs and for the middle trapezius and levator of the side holdingthe hod. The workman is apt to flex his trunk laterally to avoidputting the weight on the muscles of one side of the trunk, and thisis apt to induce lateral curvature unless the hod is carried on alter-nate Fig. 193.—^The action of the body in shoveling. Shoveling is a more complex movement. When the materialmoved is loose like sand or coal the shovel is loaded by pushing itinto the pile, using the triceps to extend the elbow and the arm-raising group to support it. When the work calls for more forcethese two groups increase their action and the abdominal muscles,particularly on the side toward the shovel, act to aid them. Theentire weight of the body is brought to bear on the work by lean- 320 INDUSTRIAL OCCUPATIONS ing forward and the rear limb helps by a push with its extensormuscles. The shovel and its load is lifted by the extensors of the spineand hips, the arms remaining extended. The hand and arm nearerthe shovel bear the whole load, the other arm pushing down on theupper end of the handle, using triceps and arm depressors. Thelifting arm is strongly supported by the trapezius and after it hasbeen raised 45 d
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