Library

Models

Published models, methods, and open-source code for occupational biomechanics, in four groups: the classic assessment methods and indices (NIOSH lifting equation, RULA, REBA, strain index…), biomechanical and physiological models of spine loading, fatigue, and metabolic cost, vision models that read posture and risk from video, and wearable-sensor models driven by IMUs, insoles, and biosensors. Each entry links to its paper, its source code where released, and the software that implements it where one exists. Looking for data instead? Browse the dataset library.

49
Models
4
Categories
9
With code
9
As software
1
Coming soon

Assessment methods & indices (9) · Biomechanical & physiological models (6) · Video & vision models (18) · Wearable-sensor models (16)

Assessment methods & indices

9 models

Published observational methods, psychophysical tables, and exposure equations.

schaub-eaws-worksheet
Paper only

EAWS: Ergonomic Assessment Worksheet (European Assembly Worksheet)

TU Darmstadt (IAD) / International MTM Directorate · 2013

First-level screening worksheet integrating working postures, action forces, manual materials handling, and repetitive upper-limb load into one whole-body physical workload score (Theor. Issues Ergon. Sci., 2013). Developed with the MTM association and widely embedded in automotive production planning and digital human modeling suites. Use of the method and training are licensed; the paper describes the structure and rationale.

whole-bodyscreeningassemblyautomotivemmhupper-limblicensed-method
InputObserved working postures, action forces, manual materials handling parameters, and upper-limb repetitive load over a shift
OutputSection scores for postures, forces, MMH, and upper limb, combined into a whole-body risk score with traffic-light zones
DomainAssembly and production work — whole-body physical workload screening, common in automotive
No code released Paper ↗
waters-revised-niosh-lifting-equation
Software

Revised NIOSH Lifting Equation (RNLE)

NIOSH · 1993

The standard model for evaluating two-handed manual lifting (Ergonomics, 1993): six task-factor multipliers reduce a 23 kg load constant to a Recommended Weight Limit, and the ratio of actual load to RWL gives the Lifting Index (Composite Lifting Index for multi-task jobs). Public domain, anchored to the 3.4 kN L5/S1 compression criterion. Implementations include NIOSH's free NLE Calc mobile app and the Applications Manual (DHHS 94-110, linked as the record); the WISHA lifting calculator derives from it.

liftingniosh-lifting-equationmmhrisk-indexpublic-domain
InputSix task factors: horizontal and vertical hand locations, vertical travel distance, asymmetry angle, lifting frequency and duration, coupling quality
OutputRecommended Weight Limit plus the Lifting Index and Composite Lifting Index
DomainTwo-handed manual lifting — task design and risk evaluation
Available as software Paper ↗Record ↗Software ↗
snook-liberty-mutual-mmh
Software

Liberty Mutual (Snook) MMH Tables and the 2021 LM-MMH Equations

Liberty Mutual Insurance Research Center · 1991

Psychophysical tables of maximum acceptable weights and forces for lifting, lowering, pushing, pulling, and carrying by male and female population percentile (Snook & Ciriello, Ergonomics, 1991), the industry standard for designing MMH tasks. Recast in 2021 as the LM-MMH regression equations (Potvin et al., Ergonomics - linked as the record), which smooth the tables into continuous equations. Free interactive web tool from Liberty Mutual; the tool loads in browsers but returns 403 to automated link checkers.

psychophysicsmmhliftingpushing-pullingcarryingdesign-limits
InputTask type (lift, lower, push, pull, carry), hand heights and distances, frequency, and object width
OutputMaximum acceptable weights and forces by population percentile - the share of workers a task design accommodates
DomainManual material handling — psychophysical task design limits
Available as software Paper ↗Record ↗Software ↗
occhipinti-ocra-index
Software

OCRA Index for Repetitive Upper-Limb Work

EPM Research Unit, Milan · 1998

The OCRA index (Ergonomics, 1998) scores repetitive upper-limb work as the ratio of technical actions actually performed per shift to a recommended number derived from force, posture, repetitiveness, recovery periods, and additional factors, yielding exposure classes for work-related upper-limb MSD risk. It is the reference method cited by ISO 11228-3 and EN 1005-5 for biomechanical overload of the upper limbs; the EPM International Ergonomics School distributes free OCRA assessment tools on its site.

upper-extremityrepetitive-motionexposure-assessmentrisk-indexiso-11228
InputTechnical actions per shift with force, posture, repetitiveness, recovery-period, and additional factors
OutputRatio of actual to recommended technical actions, classified into upper-limb risk exposure classes
DomainRepetitive upper-limb work — exposure assessment
Available as software Paper ↗Software ↗
moore-garg-strain-index
Paper only

Strain Index and Revised Strain Index for Distal Upper-Extremity Risk

Medical College of Wisconsin / University of Wisconsin-Milwaukee · 1995

The Strain Index (AIHA Journal, 1995) multiplies six task-variable ratings into a single score for risk of distal upper-extremity disorders in hand-intensive work. The Revised Strain Index (Garg, Moore & Kapellusch, Ergonomics, 2017 - linked as the record) replaces the categorical multipliers with continuous functions of force, exertion frequency and duration, and posture, and has been validated against carpal tunnel syndrome incidence in prospective cohorts. Public method; both papers are paywalled.

upper-extremitystrain-indexrepetitive-motionrisk-indexexposure-assessment
InputSix task variables: intensity of exertion, duration of exertion, efforts per minute, hand/wrist posture, speed of work, duration per day
OutputStrain Index score classifying jobs as safe or hazardous for distal upper-extremity disorders
DomainHand-intensive repetitive work — distal upper-extremity MSD risk
No code released Paper ↗Record ↗
mcatamney-corlett-rula
Code

RULA: Rapid Upper Limb Assessment

University of Nottingham (Institute for Occupational Ergonomics) · 1993

Rapid Upper Limb Assessment (Applied Ergonomics, 1993): a survey method scoring observed upper-limb, neck, trunk, and leg postures with muscle-use and force ratings into a 1-7 grand score and four action levels for work-related upper-limb disorder risk. Public method requiring no equipment; among many implementations, the linked auto_rula library (with the ergo4all mobile app) scores RULA automatically from 3D pose data under a non-commercial MIT/Commons Clause license.

rulapostural-assessmentupper-extremityobservational-methodrisk-index
InputObserved postures of upper arm, lower arm, wrist, neck, trunk and legs, plus muscle-use and force/load ratings
OutputGrand score (1-7) with an action level indicating how urgently the work needs investigation and change
DomainSeated and standing upper-limb-intensive work — observational postural risk screening
MIT with Commons Clause (non-commercial) Paper ↗Code ↗
hignett-mcatamney-reba
Code

REBA: Rapid Entire Body Assessment

Nottingham City Hospital · 2000

Rapid Entire Body Assessment (Applied Ergonomics, 2000): whole-body observational scoring of trunk, neck, leg, and arm postures combined with load, coupling, and activity ratings into a 1-15 score and five action levels, designed for the unpredictable postures of healthcare and service work. Public method requiring no equipment; the linked rs9000/ergonomics Python library (MIT) computes REBA scores automatically from 3D pose keypoints, and REBA is the risk target of several models in this library.

rebapostural-assessmentwhole-bodyobservational-methodrisk-index
InputObserved trunk, neck, leg, upper-arm, lower-arm and wrist postures plus load/force, coupling, and activity ratings
OutputREBA score (1-15) with five action levels for whole-body MSD risk
DomainWhole-body, unpredictable working postures — observational MSD risk screening
radwin-frequency-duty-cycle-hal
Paper only

Frequency-Duty Cycle Equation for the ACGIH Hand Activity Level

University of Wisconsin-Madison / University of Michigan / UCSF · 2015

Nonlinear regression equation, HAL = 6.56 ln D [F^1.31 / (1 + 3.18 F^1.31)], that predicts the ACGIH hand activity level from exertion frequency F and duty cycle D as a continuous function (Ergonomics, 2015). It closely matches the TLV lookup table while extending beyond it, and became the basis of the 2018 ACGIH HAL TLV revision. NIOSH-funded; open author PDF and CDC STACKS record available.

hand-activity-levelacgih-tlvrepetitive-motionupper-extremityexposure-assessment
InputExertion frequency (Hz) and duty cycle (%)
OutputACGIH hand activity level (HAL) rating
DomainRepetitive hand-intensive work (upper-extremity exposure assessment)
akkas-hand-speed-duty-cycle-hal
Paper only

Hand Speed-Duty Cycle Equation for Estimating the ACGIH Hand Activity Level

University of Wisconsin-Madison / University of Michigan / UCSF · 2015

Companion equation to the frequency-duty cycle model: estimates the ACGIH hand activity level directly from RMS hand speed tracked in conventional video, scaled relative to hand breadth, plus duty cycle (Ergonomics, 2015). It underpins Radwin's video-based HAL pipeline, since commercialized in patent-protected computer-vision tools (KineVid LLC, licensed through WARF). NIOSH-funded; CDC STACKS record available.

hand-activity-levelacgih-tlvvideo-analysiscomputer-visionupper-extremityexposure-assessment
InputTracked RMS hand speed (scaled by hand breadth) and duty cycle from video
OutputACGIH hand activity level (HAL) rating
DomainRepetitive hand-intensive work (video-based exposure assessment)
No code released Paper ↗Record ↗

Biomechanical & physiological models

6 models

Predictive models with explicit physical or physiological structure: spine loading, muscle fatigue, metabolic cost.

santos-virtual-human-dhm
Software

Santos Virtual Human: Predictive Digital Human Modeling

University of Iowa Virtual Soldier Research / SantosHuman Inc. · 2025

Physics- and optimization-based predictive digital human developed at the University of Iowa Virtual Soldier Research program: predicts posture, motion, strength, reach, discomfort, and joint loads from task descriptions rather than prerecorded motion. The linked chapter (DHM 2025 symposium) is a recent application evaluating the U.S. Army Combat Fitness Test biomechanically with Santos. Commercially available through SantosHuman Inc.; research versions at the Iowa Technology Institute.

digital-human-modelingpredictive-simulationoptimizationstrengthfatiguecommercial
InputTask definition, anthropometry, loads, and environment; no prerecorded motion or mocap required
OutputPredicted posture and motion, joint torques, strength percent-capable, discomfort, and fatigue measures
DomainWorkplace and defense task design — simulation-based ergonomic evaluation without motion capture
Available as software Paper ↗Software ↗
aghazadeh-coupled-ann-spine-loads
Paper only

Coupled Neural Networks for Posture Prediction and Spinal Loads

Sharif University of Technology / Shahed University · 2020

Two coupled artificial neural networks trained on 15 subjects each performing 135 load-handling activities (nine horizontal by five vertical load locations): the first predicts full-body 3D posture from a few measurable inputs, the second maps predicted posture to lumbosacral moments and spinal loads (J. Biomech., 2020, vol. 102). Bypasses motion capture and detailed biomechanical modeling for quick spine-load screening of manual handling; extended by later work from the same group. No code release.

neural-networkposture-predictionspine-loadinglow-backmmhsparse-input
InputA small set of measurable task and subject parameters (load position in space, subject anthropometry), no motion capture
OutputFull-body 3D posture (segment orientations), then lumbosacral moments and L5/S1 compression and shear loads
DomainLoad-handling activities — spine-load estimation from a few easily measured inputs
No code released Paper ↗
xia-freylaw-3cc-fatigue-model
Paper only

Three-Compartment Controller (3CC) Muscle Fatigue Model

The University of Iowa · 2008

Physiology-based muscle-fatigue model (J. Biomech., 2008) representing a muscle as active, fatigued, and resting compartments with first-order transfer rates and a feedback controller that matches activation to the target load, predicting force decay and recovery over arbitrary duty cycles. Later Frey Law group work fit joint-specific fatigue/recovery parameters against published endurance-time and intermittent-contraction data, and the model has been adopted in digital human modeling and ergonomics software.

fatigueendurancemuscle-modelphysiologydigital-human-modeling
InputTarget load intensity and duty cycle, with joint-specific fatigue and recovery parameters
OutputTime histories of active, fatigued, and resting muscle compartments; predicted force decay, endurance time, and recovery
DomainSustained and intermittent occupational exertions — muscle fatigue and endurance prediction
No code released Paper ↗
marras-lmm-lbd-risk-model
Software

Marras Lumbar Motion Monitor Low-Back Disorder Risk Model

The Ohio State University (Biodynamics Laboratory) · 1993

Logistic risk model from a case-control study of 403 industrial lifting jobs (Spine, 1993): five trunk-motion and workplace measures captured with the Lumbar Motion Monitor - a wearable exoskeleton goniometer - combine into a probability of high-risk group membership for low-back disorder. Ohio State reports the model as two to three times more predictive of occupational LBD rates than the NIOSH lifting guides; the LMM instrument is commercial and the model lives on in the OSU Spine Research Institute's risk-exposure services.

low-backliftingrisk-assessmenttrunk-kinematicsepidemiology
InputTrunk kinematics from the Lumbar Motion Monitor plus workplace measures: lift rate, maximum load moment, sagittal flexion, lateral velocity, twisting velocity
OutputProbability of membership in the high-risk group for occupational low-back disorders
DomainIndustrial lifting jobs — low-back disorder risk surveillance
Available as software Paper ↗Software ↗
marras-granata-emg-spine-model
Paper only

OSU EMG-Assisted Model of Spine Loading During Free-Dynamic Lifting

The Ohio State University (Biodynamics Laboratory) · 1997

Biologically assisted biomechanical trunk model (J. Electromyogr. Kinesiol., 1997) that drives muscle-force estimates from surface EMG of ten trunk muscles plus trunk kinematics, capturing individual recruitment and co-contraction to compute 3D L5/S1 compression and shear during unconstrained whole-body dynamic lifting. Validated through muscle-gain and predicted-versus-measured trunk-moment checks across repeated free-dynamic exertions; the methodological backbone of much of the OSU spine-loading literature. Research model; no public software release.

emgspine-loadinglow-backliftingbiomechanical-model
InputSurface EMG from ten trunk muscles plus measured trunk kinematics during whole-body lifting
OutputIndividual muscle forces and 3D L5/S1 spine loads: compression, anterior-posterior and lateral shear
DomainDynamic occupational lifting — individualized spine-load estimation
No code released Paper ↗
garg-metabolic-energy-model
Software

Garg Metabolic Energy Prediction Model for Manual Materials Handling

University of Michigan · 1978

Additive model predicting the metabolic rate of manual-materials-handling jobs (AIHA Journal, 1978): a job is decomposed into task elements whose energy costs - functions of posture, load, frequency, and body weight - sum with postural maintenance costs to give kcal/min, used for whole-body fatigue criteria and work-rest scheduling. Implemented as the free University of Michigan Energy Expenditure Prediction Program (EEPP), a legacy tool whose page blocks automated link checkers but remains live.

metabolic-costenergy-expendituremmhfatiguework-design
InputJob decomposed into task elements (lift, lower, carry, walk, hold) with posture, load, frequency, and worker body weight
OutputPredicted metabolic energy expenditure rate (kcal/min) for the job
DomainManual material handling — metabolic workload and work-rest design
Available as software Paper ↗Software ↗

Video & vision models

18 models

Models that estimate posture, activity, or ergonomic risk from video, images, or skeleton sequences.

zheng-motionbert-stonemasonry-reba
Paper only

MotionBERT-Based 3D Posture Risk Assessment for Stonemasonry Workers

Huaqiao University · 2026

Cascaded markerless pipeline for an occupational trade with high-load manual tasks: YOLOv8n worker detection, knowledge-distilled RTMPose 2D keypoints, and MotionBERT spatiotemporal 3D reconstruction feeding automated REBA scoring (Measurement, 2026). Reports 28.3 mm mean per-joint position error under obstructed field conditions and 86.2 percent agreement with expert risk classifications for stonemasonry workers. No code release.

pose-estimationtransformermotionbertrebaconstructionmarkerlesscomputer-vision
InputRGB video of stonemasonry work, processed by YOLOv8n detection and distillation-optimized RTMPose 2D keypoints
OutputMotionBERT spatiotemporal 3D pose reconstruction and frame-wise REBA postural risk levels
DomainStonemasonry construction trade — automated postural risk assessment under cluttered field conditions
No code released Paper ↗
salehi-mobile-markerless-lifting
Paper only

Mobile-Device Markerless Motion Capture for Occupational Lifting

Oregon State University / Texas A&M University · 2026

Adapts OpenCap, the open-source smartphone-based markerless motion capture platform, to occupational lifting by retraining its marker augmentation model on a large, diverse manual-lifting dataset (Appl. Ergon., 2026). Against reference motion capture, the task-specific model cut joint kinematic errors by about 37 percent versus the original OpenCap model (9.5 vs. 15.0 degrees RMSE), with gains concentrated in trunk and upper-body joints and robustness across lift heights, asymmetry angles, and camera setups.

markerlessmotion-captureopencapliftingsmartphonevalidationcomputer-vision
InputVideo from two or more mobile-device cameras, processed through the OpenCap markerless pipeline
OutputFull-body 3D joint kinematics during lifting, from a task-specific marker augmentation model
DomainManual lifting — field-viable 3D kinematics measurement for ergonomics applications
No code released Paper ↗Record ↗
rs9000-ergonomics-reba-library
Code

rs9000/ergonomics: REBA Scoring Library From 3D Pose

Independent open-source project

Python library computing REBA scores directly from 3D pose keypoints (13+2 joints as root-relative X, Y, Z coordinates), released under the MIT license. A community open-source implementation of the REBA method (see the hignett-mcatamney-reba entry in this library) rather than a published model of its own: it bolts onto the output of any pose-estimation system to turn skeletons into postural risk scores, serving as a building block for automated occupational posture-risk pipelines.

rebaposture-assessmentopen-sourcepythonskeletonlibrary
Input3D pose keypoints (13+2 joints as X, Y, Z coordinates relative to the root joint): head, shoulders, elbows, wrists, hips, knees, ankles
OutputREBA scores computed from the joint configuration
DomainOccupational posture-risk pipelines — automated REBA scoring behind any pose-estimation system
MIT Code ↗
lin-auto-method-selection-posture
Paper only

Real-Time Posture Evaluation With Automatic Ergonomic Method Selection

National Tsing Hua University · 2022

Computes joint angles from workplace video via OpenPose, then a decision tree picks the most appropriate observational method (REBA, RULA, or OWAS) from task repetitiveness and upper/lower-limb activity and scores MSD risk (Sci. Rep., 2022, open access). Tested on 15 operation videos spanning six occupational categories (assembly, maintenance, manual handling, cleaning, office work, driving), isolating the ~10% of frames that are high risk and cutting expert evaluation time by roughly 90%. No code release.

posture-assessmentopenposerebarulaowasdecision-treecomputer-vision
InputRGB video of work tasks, processed to OpenPose joint keypoints, no body-worn sensors
OutputAutomatically selected assessment method (REBA, RULA, or OWAS), its risk score, and flagged high-risk frames
DomainGeneral occupational tasks — automated observational posture assessment from workplace video
No code released Paper ↗Record ↗
lee-scaffolding-3d-pose-risk
Paper only

Real-Time Monocular 3D Pose Risk Assessment for Scaffolding Workers

Sungkyunkwan University / Gangneung-Wonju National University / KAIST · 2026

Vision-based framework estimating 3D joint angles from a single RGB camera, classifying construction-specific hazardous postures, and computing time-weighted cumulative REBA scores in real time for scaffolding work (ISARC 2026). Validation showed strong agreement with expert assessments, with stable detection of squatting postures and higher misclassification for overhead work due to depth ambiguity and self-occlusion. No code release.

pose-estimationmonocularconstructionscaffoldingrebareal-timecomputer-vision
InputMonocular RGB camera video of scaffolding workers, no wearable sensors
Output3D joint angles, construction-specific hazardous posture classes, and time-weighted cumulative REBA scores
DomainConstruction scaffolding work — continuous WMSD risk monitoring of high-risk postures
No code released Paper ↗
cruciata-lightweight-vit-posture
Paper only

Lightweight Vision Transformer for Frame-Level Posture Risk Classification

University of Palermo / Polytechnic University of Marche / University of Perugia / University of Camerino · 2025

~5M-parameter vision transformer (SPECTRE-ViT) that classifies ergonomic risk for eight anatomical regions (neck, trunk, bilateral upper/lower arms, wrists) directly from raw RGB frames in a single multi-label pass (Sensors, 2025, open access). Trained on synchronized RGB video and full-body inertial motion capture with labels from RULA thresholds; reports F1 above 0.99 and AUC above 0.996 per region with real-time inference on edge devices. Code and data are available only on request to the authors.

posture-classificationvision-transformerdeep-learningrulawmsdmanufacturingedge-computing
InputRaw RGB video frames (224x224), no skeleton reconstruction or joint-angle estimation
OutputBinary ergonomic risk labels (acceptable vs. risky) for eight body regions per frame, from RULA-derived thresholds
DomainManual manufacturing — WMSD risk monitoring on assembly, handling, and quality-control tasks
No code released Paper ↗Record ↗
chen-colearning-3d-pose-construction
Paper only

Co-Learning 3D Pose Estimation for Real-Time Construction Ergonomics

The University of Hong Kong · 2024

Lightweight monocular 3D human pose estimation model with a residual log-likelihood estimation head, trained with a co-learning scheme that draws 2D and 3D features from multi-dimension datasets simultaneously (Comput.-Aided Civ. Infrastruct. Eng., 2024). Combined with pose tracking, it recognizes workers' 3D postures in real time for on-site ergonomic risk assessment in construction. No code release.

pose-estimationmonocularconstructiondeep-learningreal-timecomputer-vision
InputMonocular RGB video of construction workers, no markers or wearable sensors
OutputReal-time 3D postures via pose tracking and ergonomic risk levels for monitored workers
DomainConstruction sites — continuous on-site ergonomic risk monitoring from a single camera
No code released Paper ↗
parsa-stcn-action-ergonomic-risk
Code

Spatiotemporal Convolutional Networks for Action Segmentation and Ergonomic Risk Prediction

University of Washington / IIT Gandhinagar · 2019

IEEE RA-L 2019 method framing worker ergonomic-risk prediction as action segmentation of task video: per-frame VGG16 features drive an encoder-decoder temporal convolutional network that labels every frame with an action class tied to a safe, monitor, or high-risk tier, reaching 87-94% F1-overlap on videos over two minutes long. Introduced the UW-IOM dataset (20 participants manipulating boxes and rods; Mendeley Data, CC BY 4.0). TensorFlow code is on GitHub (no license stated).

activity-recognitionrisk-assessmentcomputer-visiondeep-learningtensorflowtemporal-convolutional-network
InputRGB video frames; VGG16 spatial features fed to a temporal convolutional network
OutputFrame-wise action labels mapped to safe / monitor / high-risk ergonomic tiers
DomainIndoor object manipulation (warehouse-style pick-and-place) — ergonomic risk prediction
parsa-mtl-era-activity-reba
Code

MTL-ERA: Multi-Task Activity Segmentation and REBA Risk Assessment From 3D Skeletons

University of Washington · 2021

Multi-task graph convolutional network (WACV 2021) that jointly segments worker activities and regresses frame-wise REBA ergonomic-risk scores from 3D skeleton sequences: a shared GCN backbone feeds an encoder-decoder TCN segmentation head and an LSTM risk head. On the UW-IOM dataset the best variant reached 92% F1-overlap for segmentation with a REBA-score MSE of 0.61, versus 1.68 for the single-task baseline. PyTorch code is on GitHub (no license stated).

activity-recognitionrebarisk-assessmentgraph-neural-networkdeep-learningpytorchskeleton
InputSequences of 15-joint 3D skeleton keypoints from long task videos
OutputFrame-wise activity segmentation labels and continuous REBA ergonomic-risk scores
DomainIndustrial object-manipulation work — activity recognition and postural risk scoring
mehrizi-multiview-3d-lifting-pose
Paper only

Deep Multi-View 3D Pose Estimation for Lifting Motions

Rutgers University / North Carolina State University / UNC Charlotte · 2019

Two-stage deep network estimating full-body 3D pose during lifting from two ordinary camera views - an hourglass 2D module per view feeding a multi-view 3D pose generator (J. Biomech., 2019; the arXiv preprint is the FG 2018 conference version). Validated against synchronized marker-based motion capture on 12 adults performing nine lifting variations (three heights, three asymmetry angles): mean 3D joint error 14.7 +/- 3.0 mm, with larger errors at 60-degree asymmetry and shoulder height. The lifting dataset and code were not released.

pose-estimationmarkerlessliftingdeep-learningmulti-viewcomputer-vision
InputRGB video frames from two synchronized camera views at 90 and 135 degrees, no markers or depth sensors
OutputPer-frame 3D coordinates of 14 body joints
DomainManual lifting — markerless full-body 3D pose for biomechanical analysis
No code released Paper ↗Preprint ↗
greene-cv-rnle-trunk-kinematics
Paper only

Computer-Vision Trunk Kinematics Enhancement of the NIOSH Lifting Equation

University of Wisconsin-Madison / NIOSH · 2021

Extends the Revised NIOSH Lifting Equation with trunk kinematics extracted from ordinary workplace video (HFES Proceedings, 2021): reanalyzing videos from NIOSH's prospective 78-worker cohort, average trunk speed and acceleration correlated with low-back-pain outcomes, and adding them to the Lifting Index significantly improved risk prediction (p = 0.003). The underlying trunk-angle extraction method (linked as the record; Human Factors, 2022, free full text) was validated against motion capture on 216 lifting trials (mean absolute difference 14.7 degrees, r-squared = 0.80).

computer-visionliftingniosh-lifting-equationtrunk-kinematicsrisk-assessmentmarkerless
InputConventional 2D workplace lifting video processed with a computationally efficient computer-vision method
OutputAverage trunk angular speed and acceleration, combined with the RNLE Lifting Index in a logistic low-back-pain risk model
DomainManual lifting — video-based low-back-pain risk prediction
No code released Paper ↗Record ↗
cp3d-construction-pose-risk
Code

CP3D: Construction 3D Pose Dataset and Deep-Learning Ergonomic Risk Assessment

University of Alberta · 2024

Construction-specific 3D pose resource and model (Automation in Construction, 2024, open access): ~420k Vicon-captured 3D poses of 7 actors across 14 common construction activities, on a purpose-built skeletal model that supplies every joint angle REBA and RULA require, plus a PyTorch multi-person pipeline scoring worker ergonomic risk from RGB images. Models trained with CP3D outperform those trained without it. The GitHub repo carries a REBA demo (no license stated); the dataset itself is requested via a link in the README.

pose-estimationconstructionrebarularisk-assessmentdeep-learningpytorchmocap
InputRGB images of construction workers with bounding-box and root-depth information
Output3D joint coordinates on a biomechanical skeleton covering all REBA/RULA joint angles, plus REBA and RULA risk scores
DomainConstruction work — 3D pose estimation and ergonomic risk assessment
agostinelli-cv-ergonomic-assessment
Paper only

Computer-Vision REBA/RULA Assessment Validated on Real Manufacturing Lines

Universita Politecnica delle Marche / University of Macerata · 2024

Markerless ergonomic-assessment platform combining tf-pose-estimation and MediaPipe to track joint angles from work-cycle video and compute REBA, RULA, and OCRA — validated in situ on three real manufacturing production lines with 12 operators against expert ergonomists (Scientific Reports, 2024, open access). Risk-level agreement reached 40-80% depending on line and method; the authors position it for continuous monitoring alongside, not instead of, expert assessment. The linked GitHub repo holds the raw validation data; the tool's source code is not released.

computer-visionrebarulaocramarkerlessrisk-assessmentmanufacturingfield-validation
InputRGB video of work cycles from commodity action cameras behind and lateral to the workstation
OutputJoint-position and inter-limb-angle time series with REBA, RULA, and OCRA scores over the work cycle
DomainManufacturing production lines — observational postural risk scoring from video
No code released Paper ↗Record ↗
yen-radwin-mvta-video-task-analysis
Software

Multimedia Video Task Analysis (MVTA): Video-Synchronized Biomechanical Data Acquisition

University of Wisconsin-Madison · 1995

Video-based data acquisition and interactive data-extraction method (IEEE Trans. Biomed. Eng., 1995): analog biomechanical signals are recorded in synchrony with task video, and analysts mark event breakpoints while the video plays at any speed or direction to obtain elemental times, event frequencies, duty cycles and postures. Implemented as the MVTA software, distributed commercially by NexGen Ergonomics, which supplied the duty-cycle measurements behind the frequency- and hand-speed-based ACGIH HAL equations.

video-analysistime-studyduty-cyclehand-activity-levelupper-extremity
InputTask video with analyst-marked event breakpoints; optional synchronized analog channels (EMG, goniometers)
OutputElemental times, event frequency, duty cycle, postural analysis
DomainRepetitive manual work — time study and exposure assessment from task video
Available as software Paper ↗Record ↗Software ↗
wang-2d-video-lifting-monitor
Software

2D Video-Based Lifting Monitor for the Revised NIOSH Lifting Equation

University of Wisconsin-Madison / NIOSH · 2019

Single-camera computer-vision method that detects lifting instances with a motion "ghosting" effect and predicts hand and feet locations to extract the spatial and temporal factors of the revised NIOSH lifting equation (Ergonomics, 2019); in the lab its recommended-weight-limit estimates were within 0.2 kg of 3D motion capture. Builds on bounding-box lifting-posture classification (Greene et al., Human Factors, 2019); patented as US 11,450,148 (WARF) and commercialized by KineVid LLC.

computer-visionliftingniosh-lifting-equationmarkerlessdeep-learning
InputSingle sagittal-plane video camera, no sensors on the worker
OutputLift detection, hand and feet locations, and the horizontal/vertical RNLE factors for the recommended weight limit
DomainManual lifting — Revised NIOSH Lifting Equation risk assessment
Available as software Paper ↗Record ↗Software ↗
chen-video-hand-activity-level
Software

Automated Video Exposure Assessment of the ACGIH Hand Activity Level

University of Wisconsin-Madison · 2013

Marker-less digital video processing that tracks hand motion in ordinary workplace video and quantifies repetitive hand activity automatically (Human Factors, 2013), later extended to fully automated elemental-time and duty-cycle measurement (Akkas et al., Ergonomics, 2016). Together with the hand speed-duty cycle equation it forms Radwin's video HAL pipeline, patented as US 9,566,004 and commercialized by the UW-Madison spin-off KineVid LLC.

computer-visionhand-activity-levelmarkerlessduty-cycleupper-extremity
InputConventional 2D workplace video; marker-less hand tracking
OutputHand speed, duty cycle and exertion frequency, converted to an ACGIH hand activity level
DomainRepetitive hand-intensive work (upper-extremity exposure assessment)
Available as software Paper ↗Software ↗
wang-roofing-pose-estimation
Paper only

Video-Based 3D Pose Estimation for Residential Roofing

NIOSH / University of Delaware · 2022

NIOSH-University of Delaware method for estimating 3D worker pose directly from video of residential roofing tasks (Comput. Methods Biomech. Biomed. Eng.: Imaging & Visualization, 2022), a step toward markerless ergonomic exposure assessment on job sites where marker-based motion capture is impractical. Public as a paper and NIOSH record; no code release.

pose-estimationmarkerlessroofingconstructiondeep-learning
InputRGB video of roofing work
Output3D human pose (joint positions)
DomainResidential roofing (construction)
No code released Paper ↗Record ↗
kinematicnet
Code

KinematicNet: Whole-Body Kinematics From Multi-View Images

NIOSH / University of Delaware · 2023

Deep-learning model that estimates whole-body joint kinematics directly from multi-view images (Computer Vision and Image Understanding, 2023), developed in a NIOSH-University of Delaware collaboration for markerless motion analysis of occupational tasks such as roofing. Open-access preprint on arXiv; PyTorch code released on GitHub under MIT.

pose-estimationmarkerlesskinematicsroofingdeep-learningpytorch
InputMulti-view RGB images
OutputWhole-body joint kinematics
DomainOccupational tasks (residential roofing)

Wearable-sensor models

16 models

Estimation models driven by IMUs, pressure insoles, and body-worn biosensors.

vignais-realtime-rula-feedback
Paper only

Vignais Real-Time IMU Ergonomic Feedback System

Universite de Technologie de Compiegne / DFKI Kaiserslautern · 2013

Landmark IMU-network system reconstructing upper-body joint angles in real time and computing RULA continuously, with local and global risk scores fed back to the worker through a see-through display and auditory warnings (Appl. Ergon., 2013, 44:566-574). Evaluated in a simulated industrial assembly task, where concurrent feedback reduced time spent at hazardous RULA levels; the design template for later real-time wearable coaching systems. No code release.

imurulareal-timefeedbackassemblylandmark-study
InputA network of body-worn inertial sensors reconstructing upper-body joint angles
OutputContinuous RULA scores with visual and auditory feedback delivered to the worker in real time
DomainIndustrial manufacturing and assembly — real-time worker posture feedback
No code released Paper ↗
schall-fethke-field-imu
Paper only

Schall and Fethke Field IMU Method for Postural Exposure

Auburn University / University of Iowa · 2016

Establishes IMU accuracy and repeatability for direct exposure measurement in the field: trunk angular displacement and upper-arm elevation were compared with optical motion capture over eight-hour laboratory trials and during field-based dairy parlor work (Ergonomics, 2016, 59:591-602). The method underlies the group's later full-shift studies of nurses and other workers, and is a standard reference for shift-long IMU posture sampling. No code release.

imuexposure-assessmentfield-methodtrunkupper-armvalidation
InputBody-worn inertial measurement units on the trunk and upper arms during real work shifts
OutputTrunk angular displacement and upper-arm elevation angles and angular velocities over the full shift
DomainFull-shift field-based occupational exposure assessment (validated during dairy parlor work)
No code released Paper ↗
robert-lachaine-imu-validation
Paper only

Full-Body IMU Joint Angle Validation for Manual Material Handling

IRSST (Montreal) / Ecole de technologie superieure · 2017

Systematic validation of full-body inertial motion capture joint angles against an optoelectronic reference during manual material handling (Med. Biol. Eng. Comput., 2017, 55:609-619), quantifying agreement per joint and plane and the drift accumulated over task duration. Widely cited as the methodological basis for using IMU suits in MMH ergonomics studies, including the IRSST force-plate-free L5/S1 model already in this library. No code release.

imuvalidationjoint-anglesmmhmethodologymotion-capture
InputFull-body Xsens inertial motion capture suit during manual handling tasks
OutputWhole-body joint angles benchmarked against an optoelectronic reference system
DomainManual material handling — methodological basis for inertial motion capture in MMH ergonomics
No code released Paper ↗
porta-single-imu-trunk-flexion
Paper only

Single-IMU Trunk Flexion Monitoring for Warehouse Work

University of Cagliari / Virginia Tech · 2020

Continuous trunk-flexion exposure tracking with a single lower-back IMU on twelve warehouse workers during real shifts (IJERPH, 2020, open access): workers spent 5.1 percent of work time at 30-60 degrees of flexion and 2.3 percent at 60-90 degrees. Sampling-duration analysis showed that, depending on acceptable error, monitoring periods up to about 50 minutes can characterize a shift's trunk flexion exposure, supporting practical minimal-sensor surveillance. No code release.

imutrunk-flexionexposure-assessmentwarehouseminimal-sensinglow-back
InputOne inertial measurement unit worn on the lower back during actual warehouse shifts
OutputTrunk flexion exposure classified by amplitude, frequency, and duration, plus minimum sampling duration guidance
DomainWarehouse work — minimal-sensor trunk flexion exposure surveillance during real shifts
No code released Paper ↗
peppoloni-imu-emg-upper-limb
Paper only

Peppoloni IMU and EMG Upper-Limb Risk Assessment System

Scuola Superiore Sant'Anna (PERCRO Lab) · 2016

Wearable system reconstructing a 7-degree-of-freedom upper-limb kinematic chain online from IMUs fused with surface EMG via unscented Kalman filtering, feeding automatic RULA and Strain Index scoring for repetitive efforts (Int. J. Ind. Ergon., 2016, 52:1-11). An early demonstration that continuous instrumented assessment can replace intermittent observational scoring in industrial upper-limb work. No code release.

imuemgupper-limbrulastrain-indexsensor-fusionreal-time
InputWearable IMUs fused with surface EMG on the upper limb
OutputOnline 7-DoF upper-limb kinematic chain reconstruction with automatic RULA and Strain Index scoring
DomainRepetitive industrial work — online upper-limb biomechanical load monitoring
No code released Paper ↗
openpack-torch-activity-recognition
Code

OpenPack Baseline Models for Packaging Work Recognition (openpack-torch)

Osaka University · 2024

Official PyTorch baselines accompanying the OpenPack dataset (IEEE PerCom 2024): U-Net and DeepConvLSTM models on IMU acceleration and ST-GCN on skeleton keypoints, framing packaging-operation recognition as frame-wise semantic segmentation over 10 operation classes. Ships as the pip-installable openpack-torch package (MIT) with tutorials and the companion openpack-toolkit for data loading; served as the reference implementation for the OpenPack Challenge 2022.

activity-recognitiondeep-learningimuskeletonlogisticspackagingbaselines
InputWearable IMU acceleration streams and skeleton keypoints from the OpenPack dataset
OutputFrame-wise labels over 10 packaging work operations (semantic segmentation of the work period)
DomainLogistics packaging work — operation recognition for IoT-enabled warehouses
lind-kth-smart-workwear
Paper only

KTH Smart Workwear System With Haptic Posture Feedback

KTH Royal Institute of Technology · 2020

IMU-instrumented workwear that monitors trunk inclination and upper-arm elevation and vibrates to coach the wearer's work technique (Sensors, 2020, open access). Evaluated on sixteen novices in simulated mail sorting, where it reduced adverse arm movements and postures; a companion Applied Ergonomics study in real order picking showed reduced time at trunk inclinations above 20-45 degrees and arm elevations above 30-45 degrees. No code or hardware release.

imusensorized-garmenthaptic-feedbackposturework-techniqueintervention
InputIMUs carried in embedded pockets of a sensorized workwear shirt, tracking trunk inclination and upper-arm elevation
OutputContinuous posture angles plus real-time vibrotactile feedback when exposure thresholds are exceeded
DomainRepetitive manual handling — work-technique training and postural exposure reduction
No code released Paper ↗
larsen-imc-spine-loading
Paper only

Inertial Motion Capture Driven Musculoskeletal Spine Loading Model

Aalborg University · 2020

Couples full-body inertial motion capture with a detailed musculoskeletal model and predicted ground reaction forces and moments to estimate L4-L5 compression and shear during symmetric and asymmetric manual lifting (Ann. Biomed. Eng., 2020, 48:805-821). Removing force plates makes spine-load estimation feasible outside the laboratory; errors were largest for heavy asymmetric lifts. No code release.

imumusculoskeletal-modelspine-loadinglow-backmmhinverse-dynamics
InputFull-body inertial motion capture suit kinematics; ground reaction forces and moments are predicted, not measured
OutputL4-L5 compression and anteroposterior shear forces from a musculoskeletal model during lifting
DomainManual materials handling — laboratory-free estimation of lumbar spine loads
No code released Paper ↗
wu-insole-load-estimation-exo
Paper only

Insole-Pressure Load Estimation for Adaptive Lifting-Exoskeleton Control

Florida International University · 2026

Machine-learning method estimating the mass of a manually lifted object from low-cost 36-channel insole plantar-pressure data, so an upper-limb industrial exoskeleton can scale its assistance to the actual load (IEEE AIRC 2026; open preprint on arXiv). On five subjects lifting 2-10 kg, channel-based support vector regression on differential pressure reached a mean absolute error of 0.55 kg and extrapolated to held-out load levels; a MobileNetV2 pressure-map variant was a within-subject feasibility study. The code repository cited in the paper is empty as of August 2026.

pressure-insolesload-estimationexoskeletonliftingmachine-learningsvr
Input36-channel plantar pressure from a pair of low-cost instrumented insoles
OutputEstimated mass of the lifted load (2-10 kg) as a set-point for exoskeleton assistance torque
DomainIndustrial manual lifting — adaptive assistance control of upper-limb exoskeletons
No code released Paper ↗Preprint ↗
niosh-wearable-imu-lifting-risk
Paper only

NIOSH Five-IMU Wearable System for Automatic Lifting Risk-Factor Assessment

NIOSH / FocusMotion · 2020

NIOSH algorithm computing the Revised NIOSH Lifting Equation input variables from five body-worn IMUs: a wrist-motion synchronization feature drives machine-learning lift detection (85% training accuracy) and a body-segment-length ratio model derives trunk flexion and hand locations (HCII 2020, LNCS 12198). Validated against optical motion capture on 10 subjects and 360 lifting trials - duration within ~1 s, trunk angle within ~2 degrees, and hand-location errors down to 14/2.2 cm with measured segment lengths. Open copy on CDC STACKS; no code release.

imuliftingniosh-lifting-equationwearablesmachine-learningexposure-assessment
InputFive body-worn IMUs (both wrists, dominant upper arm, upper back, dominant thigh), optionally with measured body-segment lengths
OutputAutomatic lift detection plus the RNLE input variables: lifting duration, trunk flexion angle, and vertical/horizontal hand locations
DomainManual lifting — Revised NIOSH Lifting Equation exposure assessment in the field
No code released Paper ↗Record ↗
muller-imc-l5s1-moments
Paper only

Force-Plate-Free L5/S1 Moment Estimation From Inertial Motion Capture

IRSST (Montreal) / Universite Laval / LBMC (Lyon) · 2022

Estimates L5/S1 moments from full-body inertial kinematics alone (Sensors, 2022, open access): an optimization distributes external forces over discrete foot and hand contact points subject to whole-body dynamics, removing the need for force plates. Validated on nine experienced handlers each performing 156 workplace-representative box transfers with six load types: RMSE 21.4 Nm for the L5/S1 flexion moment and 15.6 Nm for the asymmetric moment, with peak/cumulative flexion indicators correlating strongly (r-squared ~0.87) but asymmetric indicators weakly (~0.31). No code release.

imuinverse-dynamicsspine-loadinglow-backmmhforce-plate-free
InputFull-body Xsens inertial motion capture (17 IMUs) only; no force plates or hand-force sensors
OutputGround reaction forces, center of pressure, and L5/S1 flexion and asymmetric moments
DomainManual material handling — spine-load assessment in workplace settings
No code released Paper ↗
mohapatra-wearable-fatigue-prediction
Code

Wearable Network for Multilevel Physical Fatigue Prediction in Manufacturing Workers

Northwestern University / Boeing / Deere & Co. / University at Buffalo · 2024

Task-agnostic XGBoost regressor predicting continuous 0-10 Borg physical fatigue from a six-location wearable network - one skin-interfaced chest biosensor plus five IMUs (PNAS Nexus, 2024, open access). Developed on 43 participants replicating two strenuous aerospace-manufacturing tasks; an asymmetric LINEX loss cut fatigue underprediction from 0.71 to 0.38 with average MAE ~2.3 across tasks and unseen users. Code is on GitHub (no license stated) and the full deidentified multimodal database is on Zenodo (CC BY 4.0).

fatiguewearablesimubiosensorsmachine-learningxgboostmanufacturing
InputChest-mounted soft biosensor (heart rate, HRV, skin temperature) plus five torso/arm IMUs and worker attributes
OutputContinuous perceived physical fatigue on a modified Borg 0-10 scale
DomainManufacturing (aerospace composite layup and wire harnessing) — physical fatigue monitoring
matijevich-trunk-imu-insole-low-back-load
Paper only

Trunk IMU + Pressure-Insole Estimation of Low-Back Loading in Manual Material Handling

Vanderbilt University · 2021

Gradient-boosted decision-tree model estimating the time-series lumbar (L5/S1) extension moment from a single trunk IMU and pressure-sensing insoles (Sensors, 2021, open access). Trained and evaluated on 10 adults each performing about 400 distinct manual-material-handling tasks against lab-based ground truth: r-squared = 0.89 (RMSE ~20 Nm) with idealized signals and r-squared = 0.80 with actual wearable sensors, with the insoles proving irreplaceable among the sensor options tested. No public code or data release.

imupressure-insolesspine-loadingliftingmachine-learningwearables
InputOne trunk-mounted IMU plus bilateral pressure-sensing insoles
OutputContinuous time-series L5/S1 lumbar extension moment
DomainManual material handling — continuous low-back load monitoring
No code released Paper ↗
faber-ambulatory-l5s1-moments
Paper only

Ambulatory 3D L5/S1 Moment Estimation From a Full-Body Inertial Suit

Vrije Universiteit Amsterdam / Liberty Mutual Research Institute / Harvard T.H. Chan School of Public Health · 2016

Inverse-dynamics method line estimating 3D L5/S1 moments from a full-body inertial motion-capture suit without force plates (J. Biomech., 2016): top-down dynamics over upper-body kinematics kept moment RMS errors under 10 Nm (~5% of peak) in trunk bending, validated against optical mocap and force plates on nine participants. The 2020 extension (linked as the record, open access CC BY) adds instrumented force shoes and hand forces for 10 kg box lifting, where the top-down variant stayed under 20 Nm (~10% of peak). No code or data release.

imuinverse-dynamicsspine-loadinglow-backliftingwearables
InputFull-body Xsens IMU suit kinematics; the 2020 extension adds instrumented force shoes and hand forces
Output3D L5/S1 moments (extension and asymmetric components) and total ground reaction force
DomainTrunk bending and manual lifting — ambulatory spine-load assessment outside the lab
No code released Paper ↗Record ↗
chae-mun-insole-joint-moments
Paper only

Insole-Only Joint and Low-Back Moment Estimation for Lifting-Exoskeleton Control

Sungkyunkwan University · 2021

Method line estimating joint moments from plantar pressure alone for lifting-exoskeleton control (Applied Sciences, 2021, open access): an SVM posture classifier feeding posture-specific LSTM regressors estimated sagittal ankle/knee/hip/L5S1 moments during squat and stoop lifting with rRMSE 8-14% against optical mocap and force plates. The 2024 extension (Actuators, linked as the record) transfers a Bi-LSTM from 70 subjects on research insoles to a low-cost 18-point insole, estimating 3-axis L5/S1 moments in asymmetric lifting at ~12% rRMSE. No code or data release.

pressure-insolesload-estimationspine-loadingexoskeletonliftingmachine-learninglstm
InputPlantar pressure alone: 99-sensor research insoles, extended by transfer learning to an 18-point low-cost insole
OutputSagittal ankle, knee, hip, and L5/S1 moments (2021); 3-axis L5/S1 moments during asymmetric lifting (2024)
DomainManual lifting — sensing for exoskeleton control without body-worn kinematic sensors
No code released Paper ↗Record ↗
gnn-mtnet-imu-video-kinematics
Coming soon

GNN-MTNet: Graph-Enhanced IMU + Smartphone-Video Fusion for Full-Body Kinematics

New Jersey Institute of Technology / Texas A&M University / Georgia Institute of Technology · 2026

Graph-enhanced multimodal deep-learning model that fuses wearable IMU signals with 2-D keypoints from dual-view smartphone video to predict 16 full-body joint angles during occupational tasks. Per-channel bidirectional LSTM/GRU encoders with temporal attention feed a 40-node anatomical graph (GATv2), so accuracy degrades gracefully when sensors are occluded or missing, and a single-step autoregressive feedback keeps predictions temporally coherent. Developed on the offshore wind turbine maintenance dataset; paper and code release pending.

kinematicsimuvideosensor-fusiongraph-neural-networkdeep-learningpytorchwind-energyladder-climbing
Input11 body-worn IMUs (3-axis accelerometer + gyroscope) and OpenPose 2-D keypoints from two smartphone videos
Output16 lower-limb, lumbar, and arm joint angles over time
DomainField ergonomics of occupational tasks (offshore wind turbine maintenance: lifting, ladder stepping, rung climbing)
Release pending Paper pending