The term “biomechanics of gait” refers to the sum of physiological functions that merge to enable a body to walk or run in a particular pattern. In studying the biomechanics of running or walking, a researcher views the body as a machine and employs the principles of physical science and mechanics to analyze whether a gait is normal and healthy or abnormal and harmful. Motion studies typically focus on two distinct aspects of the biomechanics of gait: the kinematics involved in movement and the kinetics involved in the same set of movements.
Every physical body has a signature style of standing and moving. The study of kinematics concerns itself with that style of motion; it focuses on posture, how the legs swing, how the hips and pelvis bend and whether toes point upward or forward during gait. Extension and rotation of the knee and whether feet are arched or flat are additional mechanical features of gait studied in kinematics. Kinetics studies, however, focus solely on the physics of gait, measuring the speed of the gait, how gravity pulls on the body during a walk or run and with how much force a foot hits the ground. In studying this realm of the biomechanics of gait, researchers also note how much shock the feet, legs, joints and bones absorb with every footfall and whether that shock significantly impairs gait speed.
While experts in biomechanics of gait can use eyes and cameras to visually observe kinetics and kinematics, many researchers rely on sophisticated equipment systems. The force platform, which is similar to a treadmill, is a common piece of equipment used to study gait. It records how hard and fast a person walks or runs.
Platforms are frequently used in laboratories on test subjects who have both healthy and unhealthy gaits. Other measuring equipment used in the study of the biomechanics of gait include foot switches, which attach to a person’s foot sole to gauge speed, and direct motion systems, which use a set of pulleys attached to a waist belt to measure force and velocity. In addition, electromyography systems can use electrodes to analyze muscle activity.
Gait research can be helpful for people who have had broken hip bones, knee surgery or torn tendons and ligaments. During rehabilitation, therapists can use knowledge of proper biomechanics of gait to correct gait problems in recovering patients. Sometimes, surgery, injury or simply improper form can alter biomechanics of gait, causing the core of the body to lean too far forward or the feet to rotate excessively. Over-rotation or over-extension in any part of the body during running or walking can result in the overuse of muscles, excess use of energy and the recurrence of injury.