What Is Biomechanics? Methods, Subfields, and Funding

Biomechanics is the study of the structure, function, and motion of living systems using the methods of mechanics. It asks how forces act on and within the body, how tissues deform and fail, and how organisms move, and it answers with a mix of physical measurement, mathematical modelling, and computer simulation. The scale ranges from single molecules and cells through tissues and organs to the movement of a whole person or animal. This guide defines the field, maps its major subfields, explains the core methods (motion capture, force plates, finite element modelling, and musculoskeletal simulation), traces the field’s history, and adds the research-administration layer that generic overviews leave out: who funds biomechanics, which societies and journals anchor it, and which compliance obligations come with the work.

What Is Biomechanics?

Biomechanics sits where mechanics, biology, and medicine meet. Mechanics supplies the vocabulary: force, moment, stress, strain, stiffness, fluid flow, energy. Biology and physiology supply the system under study: a bone, a tendon, an artery wall, a muscle, a joint, a running athlete, a beating heart. The central move is to treat a living structure as something that carries load, deforms, and responds to its mechanical environment, and then to measure or predict that behaviour quantitatively.

Two features distinguish biomechanics from ordinary engineering mechanics. First, living materials are rarely simple. Soft tissues are typically nonlinear, anisotropic, and time dependent, and they differ between individuals and change with age, disease, and training. Second, living tissue is not passive: bone remodels in response to load, muscle adapts to training, and cells change behaviour depending on the forces applied to them. The study of that last feedback loop is called mechanobiology, and it is now one of the most active branches of the field.

Biomechanics is practised in engineering departments, kinesiology and sport-science departments, medical schools, orthopaedic and rehabilitation research centres, and in industry (medical devices, footwear, protective equipment, automotive safety). The questions are correspondingly varied: how should a hip implant be designed so the surrounding bone is not weakened, why does a particular gait pattern overload the knee, how much stress does an aortic aneurysm wall carry before it ruptures, or how do cells sense the stiffness of the matrix they sit on.

How Biomechanics Relates to Neighbouring Fields

Biomechanics overlaps with several disciplines that are easy to confuse with it.

• Kinesiology. Kinesiology is the broader study of human movement and physical activity. Biomechanics is one of its core subfields alongside exercise physiology and motor control, so most kinesiology departments teach and research it. Biomechanics itself is wider than kinesiology, though, because it also covers non-human animals, plants, cells, and engineered devices.
• Biomedical engineering. Biomedical engineering applies engineering to medicine and biology. Biomechanics is one of its main specialisations, alongside areas such as biomaterials, bioinstrumentation, and imaging.
• Mechanical engineering. Mechanical engineering provides the solid mechanics, fluid mechanics, and dynamics on which biomechanics is built, and many biomechanics researchers are trained there.
• Biophysics. Biophysics uses physics to explain biological phenomena in general; biomechanics is the part of that territory concerned specifically with force, motion, and deformation.
• Neuroscience. Movement is produced by the nervous system acting through muscles, so the study of motor control connects biomechanics to neuroscience.

Major Subfields of Biomechanics

Musculoskeletal and Orthopaedic Biomechanics

This is the subfield most people picture. It studies bones, joints, cartilage, ligaments, tendons, and muscles, and the loads they carry during daily activity, work, and sport. Typical topics include joint contact forces, the mechanics of fracture and fracture fixation, the design and wear of joint replacements, spinal loading, and the mechanical causes of injury. It is closely tied to orthopaedic surgery and rehabilitation research.

Human Movement, Gait, and Sports Biomechanics

Here the system of interest is the moving person. Researchers describe walking, running, jumping, reaching, and balance, compare healthy and pathological movement, and look for mechanical factors in performance and injury. Clinical gait analysis, for example, is used to characterise how disease or injury alters walking. Sports biomechanics applies the same tools to technique, equipment, and injury prevention.

Tissue and Cellular Biomechanics

This subfield characterises the mechanical properties of tissues such as cartilage, skin, tendon, and bone, and increasingly the behaviour of individual cells and the extracellular matrix. It overlaps with mechanobiology, which investigates how mechanical forces influence cell signalling, tissue development, repair, and ageing. Experimental work uses mechanical testing, microscopy, and imaging-based strain measurement, paired with constitutive models of how the tissue deforms.

Cardiovascular and Fluid Biomechanics

Blood is a fluid and vessels are deformable tubes, so the circulation is a natural mechanics problem. Researchers study blood flow patterns, the stresses that flow imposes on vessel walls, the wall mechanics of arteries and aneurysms, heart valve function, and the mechanics of the heart muscle itself. Related fluid problems include airflow in the lungs and the mechanics of the eye and inner ear. Computational fluid dynamics is a standard tool here, often driven by patient-specific geometry taken from medical imaging.

Rehabilitation, Assistive, and Wearable Technology

Prostheses, orthoses, exoskeletons, and powered assistive devices all depend on a quantitative understanding of how the body moves and loads its joints. This is where biomechanics meets robotics. Wearable inertial sensors also move measurement out of the laboratory: see the dictionary entry on wearable devices and digital health technologies for how such devices are treated in clinical research.

Core Methods and Tools

Most biomechanics studies combine measurement with modelling. The standard toolkit is below.

Motion Capture

Motion capture records the position of the body in space over time. The most common laboratory approach uses multiple infrared cameras that track reflective markers attached to anatomical landmarks. Software reconstructs each marker’s three-dimensional trajectory, and a kinematic model converts those trajectories into joint angles and segment motions. Alternatives include marker-less systems that use video and computer vision, and wearable inertial measurement units that can record movement outside the laboratory. Each trades accuracy against convenience. Marker-based capture is generally treated as the reference method for laboratory work, but skin movement over underlying bone is a recognised source of error whichever system is used.

Reporting standards matter because joint angles depend on how coordinate systems are defined. The Standardization and Terminology Committee of the International Society of Biomechanics has published recommendations on joint coordinate systems for reporting human joint motion, including Wu et al. (2002) in the Journal of Biomechanics for the ankle, hip, and spine. Following such a recommendation makes results comparable across laboratories.

Force Plates and Kinetics

A force plate (or force platform) is a rigid instrumented surface that measures the ground reaction force applied to it, usually as three force components and the associated moments, and the point of application of that force. Combined with motion capture and body-segment inertial properties, ground reaction forces feed an inverse dynamics analysis that estimates the net joint forces and moments the body must have produced to generate the observed movement. Force plates are also used directly for balance and posture testing and for jump and landing studies. Other kinetic tools include pressure-sensing insoles and mats, instrumented implants, and load cells in materials-testing machines.

Electromyography

Electromyography (EMG) records the electrical activity associated with muscle activation using surface or fine-wire electrodes. It indicates when and roughly how strongly a muscle is active, and it is often used alongside motion capture to link movement to neuromuscular control. EMG does not by itself measure muscle force, which is one reason musculoskeletal models are used to estimate it.

Musculoskeletal Modelling and Simulation

Muscle forces and joint contact loads cannot usually be measured directly in living people, so they are estimated with computer models of the skeleton, joints, and muscle-tendon actuators. OpenSim, described by Delp and colleagues in IEEE Transactions on Biomedical Engineering in 2007, is a widely used open-source system for building such models and running dynamic simulations of movement. Researchers use these models to ask what-if questions that cannot be tested on people, such as how a surgical change or an altered gait would redistribute load. Model outputs depend heavily on their assumptions, so credible studies report how the model was scaled, validated, and tested for sensitivity.

Finite Element Modelling

The finite element method divides a structure into many small elements and solves the governing equations of mechanics across them numerically, yielding stress and strain fields that are hard or impossible to measure. It was introduced to orthopaedic biomechanics in 1972, when Brekelmans, Poort, and Slooff published a finite element analysis of skeletal parts in Acta Orthopaedica Scandinavica. Today it is used to model bones and implants, the spine, cartilage and soft tissue, arterial walls, and heart valves. Patient-specific models are typically built from computed tomography or magnetic resonance images, with material properties assigned to each region. The central methodological challenge is credibility: a finite element result is only as reliable as the geometry, material model, boundary conditions, and validation behind it.

Many studies chain these tools together: imaging to build a geometry, a finite element or fluid model to simulate it, and benchtop mechanical testing of tissue or implants to validate it.

A Brief History

The mechanical study of the body is old. Giovanni Alfonso Borelli’s De Motu Animalium (On the Movement of Animals), published in 1680–1681 after his death, analysed animal and human movement in rigorously mechanical terms, and he is often called the father of biomechanics. In the nineteenth century, Eadweard Muybridge and Étienne-Jules Marey pioneered the use of serial photographs to study the mechanics of locomotion, anticipating modern motion capture. In 1892 Julius Wolff published Das Gesetz der Transformation der Knochen (The Law of Bone Remodelling), the source of what is now called Wolff’s law: bone adapts its internal architecture to the loads placed on it. That idea is an early statement of mechanobiology.

The field organised itself institutionally in the 1970s. The International Society of Biomechanics was founded in 1973, the European Society of Biomechanics in 1976, and the American Society of Biomechanics in 1977. The Journal of Biomechanics began publication in 1968. In parallel, computing changed the work: the finite element method entered orthopaedics in 1972, and open-source tools such as OpenSim later made musculoskeletal simulation available to laboratories without custom software.

Societies and Journals

Professional Societies

• International Society of Biomechanics (ISB). Founded at Penn State University on 30 August 1973, after the decision to create it was made at the 3rd International Seminar on Biomechanics in Rome in 1971. Through its standardization and terminology work, ISB publishes recommendations such as the joint coordinate system definitions mentioned above.
• European Society of Biomechanics (ESB). Founded at a meeting of 20 scientists from 11 countries in Brussels on 21 May 1976, with the goal of encouraging and promoting research and information exchange in biomechanics.
• American Society of Biomechanics (ASB). Founded in Iowa City, Iowa, in October 1977 by a group of 53 scientists and clinicians, to support exchange among people working in different areas of biomechanics.

The societies cooperate, including through the World Congress of Biomechanics. National and regional societies elsewhere, such as the Australian and New Zealand Society of Biomechanics and the Japanese Society for Clinical Biomechanics and Related Research, are also affiliated with the field’s main journal.

Journals

• Journal of Biomechanics (Elsevier, since 1968), affiliated with the ASB, ESB, ISB, and several national societies.
• Journal of Biomechanical Engineering, the journal of the Bioengineering Division of ASME.
• Clinical Biomechanics (Elsevier, since 1986), with a focus on medical and clinical applications.
• Gait & Posture (Elsevier, since 1993), covering measurement and study of gait and posture.

Subfield journals and the broader biomedical engineering and orthopaedic literature also carry a great deal of biomechanics research. Authors should check each journal’s current scope, data-sharing, and authorship policies before submitting.

Who Funds Biomechanics Research?

Biomechanics is funded from both engineering and biomedical sources, and the choice of sponsor shapes how a project is framed.

• National Science Foundation (NSF). The Biomechanics and Mechanobiology (BMMB) program sits in the Division of Civil, Mechanical, and Manufacturing Innovation (CMMI) within the Directorate for Engineering. It supports fundamental research on the mechanical behaviour of biological molecules, cells, tissues, and living systems, by theoretical, computational, or experimental approaches. BMMB projects need a clear biological component and a clear mechanics component. NSF does not support clinical trials, although feasibility studies involving human volunteers or animal subjects may be supported where they fit the scientific objectives. For more on the agency see the dictionary entry on the National Science Foundation, and for how to look up funded projects see NSF award search.
• National Institutes of Health (NIH). Biomechanics is funded through several institutes depending on the application. Relevant ones include the National Institute of Biomedical Imaging and Bioengineering (NIBIB), the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) for bone, joint, and muscle problems, and the National Heart, Lung, and Blood Institute (NHLBI) for cardiovascular and pulmonary mechanics. Institute interests change, so check the current funding opportunities and use NIH RePORTER to see what each institute has actually funded. Competitiveness varies by institute and year: see NIH paylines for FY2026.
• Other sources. Depending on the application, support also comes from the Department of Defense, other federal agencies, private foundations, medical-device and sporting-goods companies, and, outside the United States, national research councils and European Union programmes.

Funder choice has a methodological consequence. A mechanistic, model-driven proposal fits NSF’s BMMB program, while a project tied to a specific disease, patient population, or clinical outcome usually belongs at an NIH institute. Reading a program’s own description before drafting is the cheapest way to avoid a mismatch.

Research Administration Considerations

Biomechanics projects raise a recognisable set of compliance and management issues.

• Human subjects. Motion-capture and force-plate studies recruit volunteers, including children, older adults, and patients, so most need review by an institutional review board. Marker placement, maximal efforts, and balance-challenge tasks should each be addressed in the protocol and consent process.
• Animal and cadaveric work. Tissue biomechanics frequently uses animal models or donated human tissue, which bring institutional animal care review or tissue-handling and biosafety requirements.
• Data management. A single gait study produces large volumes of marker trajectories, force signals, EMG, video, and model files. A data management plan should say how these are formatted, documented, stored, and shared, and how identifiable movement data and imaging will be protected. Sharing the model, the code, and the processing settings is increasingly expected for reproducibility.
• Equipment and facilities. Motion-capture and force-plate laboratories are expensive, space-hungry, and typically run as shared facilities. Recharge rates, calibration schedules, and operator training should be planned in the budget. Indirect cost recovery rules apply to the award as a whole, and equipment purchases are subject to the sponsor’s rules.
• Ergonomics. Biomechanical principles also underpin laboratory safety. See laboratory ergonomics for bench, hood, and pipetting work and the overview of human factors engineering.

Training Paths

Biomechanics researchers come from several routes. An engineering route (mechanical or biomedical engineering) emphasises mechanics, computation, and modelling. A movement-science route (kinesiology, exercise science, sport science) emphasises human subjects work, measurement, and physiology. A clinical route (physical therapy, orthopaedics, and related health professions) emphasises patient populations and translation. Graduate programmes in biomechanics exist under all three headings, and many laboratories are interdisciplinary. Core skills include mechanics and dynamics, linear algebra and numerical methods, programming for signal processing and modelling, experimental design and statistics, and anatomy. Principal investigators in this field usually need to coordinate engineers, clinicians, and technicians, so team management matters as much as technical skill; see principal investigator for how that role is defined in research administration.

Where Biomechanics Fits Among the Sciences

Because it spans physical, life, and health sciences, biomechanics does not sit neatly in one branch. The branches of science overview shows how its parent fields relate, and the research methods hub collects CASRAI guides on study design, measurement, and analysis that biomechanics studies rely on.

Frequently Asked Questions

What is biomechanics in simple terms?

Biomechanics is the application of mechanics, the physics of force and motion, to living things. It explains how bodies and tissues bear loads, move, and fail, from the scale of a cell to the scale of a whole athlete.

What is the difference between biomechanics and kinesiology?

Kinesiology is the broad study of human movement and physical activity, including physiology, motor control, and psychology. Biomechanics is the mechanical branch of that study, and it also extends beyond human movement to tissues, cells, animals, and devices.

What is the difference between biomechanics and biomedical engineering?

Biomedical engineering is a whole engineering discipline applied to health. Biomechanics is one of its major specialisations, and it is also practised outside biomedical engineering departments, for example in kinesiology and orthopaedics.

What does a force plate measure?

A force plate measures the ground reaction force exerted on it, typically as force components in three directions, the associated moments, and the point where the force is applied. Combined with motion capture, it allows estimation of joint forces and moments through inverse dynamics.

What is finite element modelling used for in biomechanics?

It estimates stress and strain inside structures that cannot be measured directly, such as bone around an implant or an arterial wall. Models are usually built from imaging data and must be validated against experiments to be credible.

Which biomechanics societies should researchers know?

The International Society of Biomechanics (founded 1973), the European Society of Biomechanics (1976), and the American Society of Biomechanics (1977) are the three principal ones, and many countries have their own national societies.

Who funds biomechanics research in the United States?

Mainly NSF, through its Biomechanics and Mechanobiology program, and NIH, through institutes such as NIBIB, NIAMS, and NHLBI, depending on the topic. The Department of Defense, foundations, and industry also contribute.

Does biomechanics research need ethics approval?

Studies involving human participants generally need institutional review board approval, and work with animals or donated human tissue needs the corresponding institutional oversight. Purely computational studies using fully de-identified or published data may need less, but the institution decides.