Designing with Data: How Motion Capture Is Transforming Ergonomics in Manufacturing and Product Development

Every day on factory floors around the world, workers perform thousands of repetitive movements. Most of these motions look harmless in isolation, but over weeks and years, they can accumulate into musculoskeletal disorders and injuries that constitute a leading category of workplace harm.

According to the U.S. Bureau of Labor Statistics, about 30% of all injuries and illnesses involving lost workdays are associated with repetitive motion or overexertion, and in manufacturing specifically, upper-limb musculoskeletal injuries account for approximately one-third of all injuries with lost workdays. NIOSH has estimated the total annual cost of work-related MSDs at $13 billion to $54 billion USD.

The challenge for ergonomists has always been measurement. Traditional ergonomic assessments rely on observational methods, such as watching a worker, scoring their posture against checklists like RULA (Rapid Upper Limb Assessment) or REBA (Rapid Entire Body Assessment) and estimating exposure. As a recent PRISMA-structured systematic review noted, these traditional methods "may suffer from subjectivity and limited sampling". They capture only a snapshot of a workday and depend heavily on the assessor's judgment.

Motion capture technology is changing that by making movement measurement objective and continuous.

What motion capture adds to ergonomics

Motion capture records the position and orientation of the body or specific body segments over time. In an ergonomics context, this means an ergonomist can capture a worker's joint angles, reach distances, movement velocities and repetition frequencies with far greater precision than the human eye allows.

A 2025 systematic review published in Sensors analysed 20 studies comparing marker-based and markerless motion capture systems for industrial ergonomic risk assessment. It found that motion capture can support objective movement assessment, real-time feedback, continuous risk detection and automated ergonomic screening, all capabilities that integrate directly with established assessment tools like RULA, REBA, EAWS, and the NIOSH lifting equation.

The key advantage is objectivity. Rather than estimating that a worker's upper arm is elevated "about 30 degrees," mocap records the exact angle, how long it is sustained and how often it repeats. Then this precision data can be mapped directly onto ergonomic risk thresholds.

The four technology families

Not all motion capture systems work the same way. It’s important to explore each technology's distinct strengths, limitations and ideal use cases.

Optical marker-based systems

Optical marker-based systems use arrays of cameras to track reflective markers placed on a subject's body. They are the gold standard for accuracy in biomechanical measurement, consistently achieving low joint-angle errors below 3 degrees and high spatial precision.

OptiTrack, a leading manufacturer in this space, delivers sub-millimeter accuracy for its movement sciences systems, with the PrimeX 22 cameras offering ±0.15mm precision at frame rates up to 360 FPS. In one published ergonomic study, an OptiTrack system with eight PrimeX 22 cameras served as the reference for validating both inertial and video-based ergonomic assessment methods, using 39 biomechanical markers placed on the subject.

The trade-off is infrastructure. Marker-based systems require controlled environments, calibration and markered suits. As the 2025 systematic review noted, their cost, specialised equipment requirements and setup complexity can limit their use in real-world industrial environments.

Markerless optical systems

Markerless systems use cameras and AI-driven pose estimation to track human movement without markers or suits. This removes the biggest barrier to workplace adoption, as workers can be captured in their own clothing or uniform, performing job tasks with minimal setup.

Theia (above) uses deep-learning AI to track 124 keypoints on the body, delivering precision of less than 1 cm and 3 degrees. 

Captury offers a different flavour of markerless capture. Its CapturyLive platform provides real-time 3D motion tracking from video cameras, capable of tracking multiple actors simultaneously, including full body, fingers and face. 

However, markerless systems do have limitations. The PRISMA review noted that they remain "sensitive to occlusion, clothing, and environmental variability". The 2025 Sensors review found markerless systems suitable for "ergonomic screening in structured or moderately complex industrial scenarios" but not yet a replacement for marker-based precision.

Inertial systems

Inertial measurement unit (IMU) systems use wearable sensors containing accelerometers, gyroscopes and magnetometers to track body segment orientation and movement. They require no cameras and no line of sight, making them well-suited to field deployment on shop floors.

Noitom's Perception Neuron series is a prominent example. They offer wireless anti-magnetic systems (PN Studio) and wired inertial systems (PN Link) designed for continuous data acquisition in complex environments.

The accuracy of inertial systems has been validated against optical gold standards, however inertial systems do have caveats. They can be intrusive to wear, require calibration procedures, and may be affected by magnetic interference in environments with heavy machinery. 

Electromagnetic tracking

Electromagnetic tracking, while less commonly associated with ergonomics, occupies a valuable niche. Polhemus, the pioneer in this space, uses proprietary AC electromagnetic technology to provide true six-degrees-of-freedom tracking without cameras, line of sight, or optical markers. Sensors can be embedded inside objects or concealed beneath clothing, and tracking continues uninterrupted through occlusion, even in complete darkness.

The system requires only three components: a source (transmitter), sensors, and a Systems Electronic Unit that streams data at 60 to 960 Hz. Its solid-state technology never suffers from drift, a persistent challenge for inertial systems.

The trade-off is range and environmental sensitivity. The working volume is bounded by the transmitter's magnetic field rather than being scalable like an optical camera array, and metallic objects in the workspace can distort the field and degrade accuracy. 

Polhemus’ official statement on metallic distortion states: “The majority of the time, Polhemus electromagnetic tracking solutions do not encounter any issues with metallic distortion (a non-linear signal corruptor which induces accuracy degradation in the tracker's output).”

Manufacturing and product development applications

In manufacturing, motion capture enables a range of ergonomic interventions. Workstations can be redesigned based on reach and posture data rather than guesswork, and assembly tasks can be analysed cycle by cycle to identify cumulative exposure patterns. 

In product development, motion capture supports human-centred design from the earliest prototype stages. Designers can evaluate how a worker interacts with a tool, whether a control panel is within comfortable reach, or whether a vehicle cab accommodates different body sizes. Markerless systems like Captury, which can be operated without specialised personnel and set up in a matter of hours, lower the barrier to conducting ergonomic studies during the design process rather than after a product ships.

The integration of motion capture with digital human modeling, virtual reality, and CAD environments is an emerging frontier. Markerless systems can be integrated with virtual workplace prototyping and AI-driven analysis, supporting the human-centered goals of Industry 5.0.

Choosing the right system

No single technology is best for every application. The choice depends on the environment, the required accuracy, the acceptable setup burden and the number of subjects.

For maximum precision in controlled lab settings - such as validating a new tool design or conducting certification-grade assessment - optical marker-based systems like OptiTrack remain the reference standard.

For scalable, non-intrusive workplace monitoring - such as continuous screening on an assembly line - markerless systems from Captury offer the lowest setup burden and the greatest scalability.

For field capture where camera infrastructure is impractical - such as tracking workers across a large factory - inertial systems from Noitom provide portability and real-time data.

For constrained spaces where line of sight is impossible - such as inside a vehicle cab or beneath equipment - electromagnetic tracking from Polhemus fills a gap no other technology addresses.

Motion capture is empowering ergonomists 

All technologies require careful validation against the specific tasks and environments where they will be deployed, but the trajectory is clear. Motion capture is transforming ergonomics from a discipline that relies on observation and estimation to one grounded in objective, measurable movement data.

For manufacturers, that means earlier risk detection, better design and fewer injuries, and for product developers, it means designing for real human bodies from the start. For ergonomists, it means better evidence to support the decisions they have always made - now with the data to back them up.

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Our team of motion capture experts can work with you to find the best tracking solution for your needs. Get in touch today: sales@target3d.co.uk