Trunk flexion from anatomical position occurs around the X axis in which direction?

Trunk flexion from the anatomical position occurs around the X axis and is characterized by bending forward at the waist. In this movement, the upper body moves closer to the thighs, which corresponds to a decrease in the angle at the hip joint. The positive direction for flexion is typically defined as moving forward or downward toward the ground.

Therefore, when assessing the movement around the X axis, we denote this forward bending or flexion as +θX. This is consistent with standard biomechanical conventions where movements in the positive direction are considered to reflect flexion. Thus, recognizing trunk flexion in this manner provides clarity in understanding how body segments move relative to each other in three-dimensional space.

In summary, trunk flexion is identified as +θX, aligning with the standard definitions of movements and the axes around which they occur in clinical biomechanics.