biomechanics, in science, the study of biological systems, particularly their structure and function, using methods derived from mechanics, which is concerned with the effects that forces have on the motion of bodies. Ideas and investigations relating to biomechanics date back at least to the Renaissance, when Italian physiologist and physicist Giovanni Alfonso Borelli first described the basis of muscular and skeletal dynamics. Research in biomechanics became more widely known in the 20th century.

Contemporary biomechanics is a multidisciplinary field that combines physical and engineering expertise with knowledge from the biological and medical sciences. There are multiple specialty areas in biomechanics, such as cardiovascular biomechanics, cell biomechanics, human movement biomechanics (in particular orthopedic biomechanics), occupational biomechanics, and sport biomechanics. As an example, sport biomechanics deals with performance improvement and injury prevention in athletes. In occupational biomechanics, biomechanical analysis is used to understand and optimize mechanical interaction of workers with the environment.

Biomechanics research has fueled a diverse range of advances, many of which affect daily human life. Development of the biomechanics of labour, for example, focused on increasing worker efficiency without sacrificing labour safety. It resulted in the design of new tools, furniture, and other elements of a working environment that minimize load on the worker’s body. Another development was clinical biomechanics, which employs mechanical facts, methodologies, and mathematics to interpret and analyze typical and atypical human anatomy and physiology.

During World War I and World War II, there was significant focus on the development of prosthetic limbs for amputee veterans, which led to major progress in biomechanics and rehabilitation medicine. Work in that area focused on increasing the mechanical efficiency of orthopedic implants, such as those used for hip or knee replacements. A biomechanics research-based approach also helped contribute to improvements in walking devices designed for individuals with lower-leg amputation and children with cerebral palsy. The development of a new class of prosthetic feet that store and return mechanical energy during walking allowed for a reduction of metabolic expenditure in amputees and made it possible for individuals with amputation to participate in athletic activities. The biomechanically based design of assistive devices, such as wheelchairs, and the optimization of environmental elements, such as stairs, allowed individuals with disabilities to improve their mobility.

The applications of biomechanics are wide-ranging. Some examples include the use of biomechanical analysis in the design of implantable artificial prostheses, such as artificial hearts and small-diameter blood vessels; in the engineering of living tissues, such as heart valves and intervertebral discs; and in injury prevention related to vehicle accidents, including low-speed collisions involving minor soft-tissue injuries and high-speed collisions involving severe and fatal injuries.