Pick the wrong method and you get a precise score that misses the real risk. This guide explains what each method measures, how to choose between them task by task, and how to apply them so the results hold up.
Every assessment starts with a choice that is easy to get wrong. A lifting task scored with a posture method misses the load; a repetitive task scored with a lifting method misses the repetition that is wearing out the shoulder. The cost of those blind spots is large.
3 in 5
workers in the EU report musculoskeletal complaints — the most common work-related health problem in Europe.
EU-OSHA, Work-related MSDs, facts and figures (2019)$13.7 bn
a year: what overexertion from lifting, pushing, pulling and carrying costs US employers, the costliest cause of serious workplace injuries (2022 data).
Liberty Mutual Workplace Safety Index 2025937,620
musculoskeletal cases with days away, restricted work or job transfer in the US private sector in 2023–2024.
National Safety Council, Injury Facts (BLS data)26 days
median time away from work after a shoulder injury in 2023–2024, against 8 days for all lost-time cases.
National Safety Council, Injury Facts (BLS data)From chapter 2
Answer up to four questions about one task. It’s the same decision tree the guide walks through, with the reasons behind each branch.
Question 1 of 4
Does the operator lift or lower a load with both hands, 3 kg or more, as a regular part of the task?
Question 2 of 4
Does the task repeat the same arm and hand actions, in cycles or recurring patterns, for an hour or more per shift?
Question 3 of 4
Does the operator bend, twist, kneel or reach into awkward postures during the task?
Question 4 of 4
Does the operator push or pull a load on wheels, such as a trolley or a pallet truck?
Your result
This task needs
None of the four signals applies. Screen the task with REBA to confirm, then revisit if the task changes.
The question each one answers, the body region it protects and what none of them measure.
A four-step decision tree, the signals that you picked the wrong one and a checklist before you start.
The load constant, the six multipliers, the Lifting Index and how to measure H, V, D and A properly.
Checklist or Index, the five factors it scores, the colour bands and how to count technical actions.
Group A and Group B scores, load, coupling and activity, and the five action levels.
Picking from a low pallet, assembly at a bench and closing boxes, with the inputs and scores step by step.
The five errors behind most unreliable scores, with a checklist to run after every assessment.
How to assess tasks with several demands and in which order to map a whole line.
Excerpt · Chapter 1
The three methods answer different questions. That is the most important thing to know about them.
NIOSH asks: how heavy can this lift be? It was developed by the US National Institute for Occupational Safety and Health to prevent low-back pain from two-handed lifting and lowering. It gives you a Recommended Weight Limit for the specific conditions of the task and compares it with the actual load.
OCRA — Occupational Repetitive Actions — asks: how much repetitive effort can the arms and hands sustain over a shift? It was developed in Italy by Colombini and Occhipinti for tasks that repeat the same actions in cycles or recurring patterns, such as assembly, packing and machine feeding, and it is the method referenced in ISO 11228-3 and EN 1005-5. It weighs how often the hands act, how hard, in which postures and with how much recovery time.
REBA — Rapid Entire Body Assessment — asks: how risky is this posture? It was published by Hignett and McAtamney in 2000 to score whole-body postures quickly, including the trunk, neck and legs, with corrections for load, grip and activity. It is a snapshot method: you score the worst or most frequent posture, not the whole shift.
| Criterion | NIOSH | OCRA | REBA |
|---|---|---|---|
| Designed for | Two-handed lifting and lowering | Repetitive upper-limb tasks | Whole-body postures |
| Main body region | Lower back | Shoulder, elbow, wrist, hand | Trunk, neck, legs, arms, wrists |
| Key inputs | Load, H, V, D, A, frequency, grip | Action frequency, force, posture, recovery, additional factors, duration | Joint angles, load, coupling, activity |
| Result | Recommended Weight Limit and Lifting Index | Checklist score or OCRA Index, with risk bands | Score from 1 to 15 and an action level |
| Reference | NIOSH Applications Manual, 1994 | ISO 11228-3 · EN 1005-5 | Hignett & McAtamney, 2000 |
None of the three assesses vibration exposure as such (OCRA only adds points for vibrating tools), fatigue over a whole day of mixed tasks, or psychosocial load. And none of them replaces a conversation with the people doing the work. They are screening and prioritisation tools: they tell you where the risk is and how big it is, so you can decide what to change first.
HSE managers who need to justify which method they use in an audit, and why.
Ergonomists who want a shared reference for assessors across shifts and plants.
Industrial engineers redesigning stations who need to know what moves the score.
They answer different questions. NIOSH sets a recommended weight limit for two-handed lifting and lowering and compares it with the real load. OCRA scores repetitive work of the arms and hands over a shift, for each side. REBA scores a single whole-body posture from 1 to 15. Choose the method from what the operator actually does; many stations need more than one.
No. REBA scores one posture at one moment, with a coarse correction for repeated actions. It does not weigh the frequency of technical actions, force over the cycle, recovery or the duration of repetitive work, which is what OCRA measures. Use REBA to flag awkward whole-body postures and OCRA for repetitive upper-limb work.
When an operator lifts or lowers a load with both hands as a regular part of the task; ISO 11228-1 applies from 3 kg. The equation starts from a load constant of 23 kg, reduces it with six multipliers for the geometry, frequency and grip of the lift, and compares the result with the real load to give the Lifting Index.
In the original method, a score of 1 is negligible risk and no action is necessary. From 2 to 3 the risk is low and action may be necessary; from 4 to 7 it is medium and action is necessary; from 8 to 10 it is high and action is necessary soon; from 11 to 15 it is very high and action is necessary now.
Yes. ISO 11228-3, on repetitive movements and exertions of the upper limbs, refers to the OCRA method, with the OCRA Index as its preferred detailed tool; its second edition was published in 2026. OCRA is also referenced in EN 1005-5, and ISO TR 12295 points to the OCRA Checklist for screening and mapping repetitive work.
Yes, and many stations need it. Split the job into tasks, assess each demand with its own method (NIOSH for lifts, OCRA for repetitive arm work, REBA for awkward postures, Snook & Ciriello for pushing and pulling) and report the results side by side. Do not average them into a single number.
Yes. The full guide is free to read online and to share inside your organisation. Leave your work email on the guide page to get access; we use it only for your request and never add you to a newsletter without your consent.
Guide
How the OCRA High-Precision Checklist builds its score from measured times, what each of the five risk bands means, why the boundary moved from 14 to 16, and when you need the OCRA Index instead.
Guide
How to assess trolleys, pallet trucks and carts: initial and sustained force, the Snook & Ciriello tables, the two methods of ISO 11228-2 and how to read the Movement Index.
Guide
Who to film, how long to record, how to frame the operator and what to sort out before the first video: the field rules that decide whether a video-based risk score can be trusted.