What Is Biomechanics? A Guide to Human Movement Analysis 

Every movement the human body makes is the result of forces acting on and within the body. Biomechanics is the science that measures those forces and explains their effects. This guide covers what biomechanics is, the main areas within it, how a movement analysis is carried out, and how it is applied in sport, research, and clinical settings. 

Biomechanics is the study of how mechanical forces act on and within living organisms, and how those forces produce movement. It applies the principles of mechanics, force, motion, energy, and material behavior to biological structures such as bones, muscles, tendons, and joints to understand how and why the body moves as it does. 

In practice, biomechanics answers two linked questions: what is the body doing, and what is causing it to do that? A sprinter’s stride, a patient’s walking pattern, and a warehouse worker’s lifting technique can all be described in the same mechanical terms, angles, velocities, forces, and loads. Sitting at the intersection of anatomy, physiology, physics, and engineering, biomechanics is used wherever movement needs to be measured objectively rather than judged by eye. 

Biomechanics is usually divided into sub-disciplines defined either by what is being measured or by the setting in which it is applied. 

1. Kinematics

Kinematics describes motion without reference to the forces causing it. It covers joint angles, segment positions, displacement, velocity, and acceleration— for example, how far the knee flexes during a squat. Kinematics is the foundation of most movement analysis because it produces the descriptive picture against which everything else is interpreted. 

2. Kinetics

Kinetics deals with the forces and moments that cause motion: ground reaction forces, joint moments, muscle and tendon loading, and mechanical power. Where kinematics tells you that a runner’s knee collapses inwards, kinetics helps explain the loading pattern behind it. 

3. Sports Biomechanics

Sports biomechanics applies these measurements to athletic performance: refining technique, quantifying power transfer, informing equipment design, and identifying loading patterns associated with injury risk. 

4. Clinical and Rehabilitation Biomechanics

This area studies movement in the context of injury, surgery, neurological conditions, and recovery. Gait analysis is a well-known example, providing objective measurements of walking patterns that support assessment and tracking of progress over time. 

5. Occupational and Ergonomic Biomechanics

Occupational biomechanics examines movement and loading in the workplace, lifting, repetitive tasks, posture, and tool design, to reduce musculoskeletal strain. 

6. Tissue and Musculoskeletal Biomechanics

At a smaller scale, tissue biomechanics investigates how bone, cartilage, muscle, and tendon respond to load, as well as their stiffness, elasticity, and failure thresholds. This work underpins implant design, prosthetics, and computational modeling of the musculoskeletal system. 

Human movement analysis is the process of measuring, quantifying, and interpreting how a person moves. It is the applied arm of biomechanics, where biomechanics provides the theory, and movement analysis provides the measurement. 

Analysis can be qualitative or quantitative. Qualitative analysis relies on structured observation, a coach or clinician watching a movement and describing what they see. It is quick and accessible, but subjective and limited by the eye’s resolution. Quantitative analysis uses instrumentation to produce numerical data on positions, angles, forces, and timing, making it repeatable and comparable between sessions, individuals, and normative datasets. 

A movement analysis is a structured assessment in which a person performs specific tasks while instrumentation records their movement, producing data that is then processed and interpreted. Most analyses follow the same five stages. 

1. Define the question. The task, the variables of interest, and the intended outcome are agreed upon first. A return-to-sport screen, a gait assessment, and a technique review each demand a different protocol. 
2. Set up and calibrate. The capture volume is calibrated, equipment is synchronized, and, in marker-based systems, reflective markers are placed on anatomical landmarks. A static reference trial is usually captured to build the subject’s biomechanical model. 
3. Capture the movement. The participant performs the task while cameras, force plates, and any additional sensors record simultaneously. Several repetitions are usually captured so representative trials can be selected. 
4. Process the data. Raw data is reconstructed, labeled, filtered, and gap-filled, then combined with the biomechanical model to calculate joint angles, moments, powers, and event timings. 
5. Interpret and report. Results are compared against normative data, the individual’s own baseline, or the opposite limb, and translated into findings a coach, clinician, or researcher can act on. 

Accuracy depends heavily on the first two stages. Marker placement, calibration quality, and model choice all influence the output, which is why standardized protocols matter as much as the hardware itself. 

Biomechanics in sport is the measurement of an athlete’s movement in order to improve technique, increase efficiency, and manage injury risk. Rather than replacing coaching judgment, it gives coaches objective evidence for decisions that would otherwise rest on observation alone. Typical applications include: 

• Technique refinement: identifying where power is generated and where it is lost through the kinetic chain, from a bowling action to a rowing stroke. 

• Injury risk screening: quantifying asymmetries and loading patterns associated with elevated risk, such as knee valgus on landing. 

• Return-to-play decisions: comparing an injured limb with the uninjured side to inform staged progression back to competition. 

• Equipment and footwear design: testing how kit affects loading, comfort, and performance. 

• Talent identification and development: tracking movement quality as young athletes grow and train. 

In clinical research and gait laboratories, biomechanics provides objective measurements of movement that support assessment and help track change over time. Instrumented gait analysis is the most established application, widely used in the study of cerebral palsy, stroke recovery, amputee gait, and lower-limb orthopedic conditions. 

Common uses include informing surgical planning discussions, evaluating the effect of orthotics and prosthetic components, quantifying rehabilitation progress with measurements rather than impressions, and generating the datasets behind outcome studies. Because the same protocol can be repeated months apart, it is particularly valuable for longitudinal work in which subtle changes matter. 

Biomechanical analysis draws on several complementary technologies, usually synchronized so the data streams can be interpreted together. 

• Optical motion capture: multiple calibrated cameras track reflective markers to reconstruct three-dimensional movement with high precision. This remains the reference method for laboratory-based analysis. 

• Markerless motion capture: computer vision models estimate body position from video, removing marker placement and reducing setup time. It is increasingly used alongside marker-based capture where speed and ease of data collection are priorities. 

• Force plates: embedded in the floor to measure ground reaction forces, which are combined with kinematic data to calculate joint moments and powers. 

• Electromyography (EMG): records muscle activation timing and intensity. 

• Inertial measurement units (IMUs): wearable accelerometers and gyroscopes that allow capture outside the laboratory. 

• Pressure mapping: measures load distribution across the foot or seated surface. 

• Analysis software: processes raw data, applies biomechanical models, and produces reports for coaches, clinicians, and researchers. 

Vicon’s optical and markerless motion capture systems are used in gait laboratories, sports science departments, and research institutions worldwide to capture the movement data that underpins this work. 

• Biomechanics is the study of how mechanical forces act on and within living bodies to produce movement. 

• Kinematics describes motion; kinetics explains the forces behind it. Together, they form the basis of most analysis. 

• Human movement analysis is the applied measurement of movement, and can be qualitative (observational) or quantitative (instrumented). 

• A movement analysis typically follows five stages: define the question, set up and calibrate, capture, process, and interpret. 

• In sport, biomechanics supports technique refinement, injury risk screening, return-to-play decisions, and equipment design. 

• In clinical research, instrumented gait analysis provides objective measurements that support assessment and long-term tracking. 

• Optical and markerless motion capture, force plates, EMG, and IMUs are the core technologies used to collect biomechanical data.