About long bone photography, the correct statement is

The long axis is parallel to the short axis of the membrane, and the joint surface is the same height and aligned at the same position.

1, the long axis is parallel to the short axis of the film: when the doctor shoots, the long axis of the long bone is parallel to the short axis of the film, so that a clear and undistorted image can be obtained.

2, the joint surface is the same height: the doctor needs two positions for photography, including the positive position and the lateral position. In both shooting positions, the articular surface is kept at the same height.

3. Alignment of the same part: two shooting positions of the same part are aligned at the same end as the upper and lower limbs to ensure the consistency of contrast.