Here is a brief, advanced-undergraduate intro paragraph for a moment analysis section in a biomechanics assignment:

Moment analysis is a foundational concept in biomechanics, concerned with the rotational effects that forces produce about a defined axis or point. A moment (or torque) is mathematically expressed as M = F × d, where F is the applied force and d is the perpendicular distance from the line of action of that force to the axis of rotation - known as the moment arm. In the context of the human musculoskeletal system, moments govern joint kinematics and the mechanical demands placed on muscles, ligaments, and bone. Skeletal muscles rarely act along the line connecting two joints; instead, they generate force at an offset, creating moments that produce or resist angular motion at the joint. Quantifying these moments is essential for understanding movement efficiency, joint loading patterns, injury mechanisms, and the design of orthotic or prosthetic devices. This analysis applies the principles of static and dynamic equilibrium to characterize the net moments acting at selected joints during a given movement task.

Feel free to ask if you want it adjusted - shorter/longer, a different joint focus (e.g., knee, shoulder), or with specific equations formatted for a report.