Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

What describes the shape of an infant's head associated with lateral strain?

1. Round and symmetrical

2. Long and narrow

3. Parallelogram shape

4. Square and flat

The correct answer is: Parallelogram shape

The description of an infant's head associated with lateral strain is characterized by a parallelogram shape. This occurs due to the asymmetrical forces acting on the skull, often resulting from positional molding or mechanical stress during delivery. When lateral strain is present, the bones of the skull can be displaced in such a way that the front and back of the head become elongated while the sides appear flattened. This specific deformation leads to the characteristic parallelogram shape, wherein the head's overall symmetry is disrupted, creating slanted contours. In understanding head shapes in infants, recognizing the distinct changes that lateral strain causes is crucial. Other shapes, such as round and symmetrical, long and narrow, or square and flat, do not adequately represent the deformation that occurs with lateral strain. A round and symmetrical shape suggests no strain or molding, while a long and narrow shape indicates a different pattern of cranial molding typically not associated with lateral strain. A square and flat shape may describe a different type of cranial deformation, rather than the unique parallelogram formation characteristic of lateral strain.