What axis does moving forward and backward correspond to in human biomechanics?

In human biomechanics, moving forward and backward corresponds to the z-axis. This axis typically represents movements along the sagittal plane, which divides the body into left and right halves. When a person moves forward, such as in walking or running, they are translating their body along this axis in a positive direction. Conversely, moving backward involves a negative translation along the same axis.

Understanding the axes of movement is essential in biomechanics as it allows for a better grasp of how different motions occur in relation to the body's structure. Movements associated with the x-axis generally involve lateral motion (side to side), while the y-axis is often associated with vertical motion (up and down). The w-axis is less commonly referenced, particularly in standard biomechanical frameworks, making the z-axis the relevant choice for forward and backward movements.