A Practical Physiology: A Text-Book for Higher Schools

by Albert F. Blaisdell

I. Bony Landmarks.

1. The occipital protuberance can be distinctly felt at the back of the head. This is always the thickest part (often three-quarters of an inch or more) of the skull-cap, and is more prominent in some than in others. The thinnest part is over the temples, where it may be almost as thin as parchment.

2. The working of the condyle of the lower jaw vertically and from side to side can be distinctly felt and seen in front of the ear. When the mouth is opened wide, the condyle advances out of the glenoid cavity, and returns to its socket when the mouth is shut. In front of the ear, lies the zygoma, one of the most marked and important landmarks to the touch, and in lean persons to the eye.

3. The sliding movement of the scapula on the chest can be properly understood only on the living subject. It can move not only upwards and downwards, as in shrugging the shoulders, backwards and forwards, as in throwing back the shoulders, but it has a rotary movement round a movable center. This rotation is seen while the arm is being raised from the horizontal to the vertical position, and is effected by the cooperation of the trapezius with the serratus magnus muscles.

4. The patella, or knee-pan, the two condyles of the tibia, the tubercle on the tibia for the attachment of the ligament of the patella, and the head of the fibula are the chief bony landmarks of the knee. The head of the fibula lies at the outer and back part of the tibia. In extension of the knee, the patella is nearly all above the condyles. The inner border of the patella is thicker and more prominent than the outer, which slopes down toward its condyle.

5. The short, front edge of the tibia, called the “shin,” and the broad, flat, subcutaneous surface of the bone can be felt all the way down. The inner edge can be felt, but not so plainly.

6. The head of the fibula is a good landmark on the outer side of the leg, about one inch below the top of the tibia. Note that it is placed well back, and that it forms no part of the knee joint, and takes no share in supporting the weight. The shaft of the fibula arches backwards and is buried deep among the muscles, except at the lower fourth, which can be distinctly felt.

7. The malleoli form the great landmarks of the ankle. The outer malleolus descends lower than the inner. The inner malleolus advances more to the front and does not descend so low as the outer.

8. The line of the clavicle, or collar bone, and the projection of the joint at either end of it can always be felt. Its direction is not perfectly horizontal, but slightly inclined downwards. We can distinctly feel the spine of the scapula and its highest point, the acromion.

9. Projecting beyond the acromion (the arm hanging by the side), we can feel, through the fibers of the deltoid, the upper part of the humerus. It distinctly moves under the hand when the arm is rotated. It is not the head of the bone which is felt, but its prominences (the tuberosities). The greater, externally; the lesser in front.