The KIM-LHC (Key Indicator Method — Lifting, Holding, Carrying) is a screening tool for evaluating the physical load of manual handling tasks. It was developed by the German Federal Institute for Occupational Safety and Health (BAuA). Motionprint Ergo implements it in full — automatically extracting body posture, load handling, and biomechanical variables from motion capture data and computing the risk score for every lifting task in your recording. This article explains how the method works, what each scoring component represents, and how to interpret your results.
1 Overview
KIM-LHC produces a single Total Score for each lifting task. The Total Score determines the risk level across four categories:
| Total Score | Risk Level | Interpretation |
|---|---|---|
< 20 |
Low risk | Physical load is low. Health consequences from physical overload are unlikely. |
20 – 50 |
Slightly increased risk | Physical overload is possible for less resilient persons. Workplace redesign for this group may be helpful. |
50 – 100 |
Substantially increased risk | Physical overload is also possible for normally resilient persons. Workplace redesign is recommended. |
≥ 100 |
High risk | Physical overload is likely. Workplace redesign is necessary. |
Motionprint Ergo derives body posture classification, trunk bending/twisting, hand position, load handling asymmetry, and hand-arm movement automatically from your motion capture data — no manual posture observation required.
2 The Total Score Formula
The Total Score is calculated by multiplying the Rating Points by the Time Rating:
Rating Points is itself the sum of five individual scoring components:
Each component contributes points that reflect a specific aspect of physical workload. The Time Rating then acts as a multiplier that scales the total based on how frequently the task is repeated during the work shift. A high Rating Points value at low frequency can still produce an acceptable Total Score, and vice versa — frequency is a critical part of the overall assessment.
Points based on the weight of the handled object, differentiated by worker gender. Heavier loads produce a higher rating.
Points based on how symmetrically the load is held, determined by the lateral and vertical asymmetry between the left and right hands.
Points based on the worker's start and finish posture, plus additional points for specific posture conditions such as trunk twisting and elevated hand positions.
Points for six environmental and task condition factors, including hand/arm movement, difficulties holding/carrying, force transfer, spatial constraints, and clothing.
Points reflecting the quality of task scheduling and rest provisions — whether the work organization is good, restricted, or unfavorable.
3 Load Rating
The Load Rating is determined by the weight of the object being handled. When gender is enabled in the KIM-LHC settings, the rating is differentiated by worker gender, reflecting physiological differences in load capacity. When gender is disabled, the women's reference values are applied. The weight category is entered manually per lifting task.
Note that the 0 – 3 kg weight category is switched off by default and is not part of the official KIM-LHC method. It can be enabled in the KIM-LHC report settings if your assessments require it.
| Weight | Points | |
|---|---|---|
| 0 – 3 kg | 2 | |
| 3 – 5 kg | 4 | |
| 5 – 10 kg | 6 | |
| 10 – 15 kg | 8 | |
| 15 – 20 kg | 11 | |
| 20 – 25 kg | 15 | |
| 25 – 30 kg | 25 | |
| 30 – 35 kg | 35 | |
| 35 – 40 kg | 75 | |
| > 40 kg | 100 |
| Weight | Points | |
|---|---|---|
| 0 – 3 kg | 4 | |
| 3 – 5 kg | 6 | |
| 5 – 10 kg | 9 | |
| 10 – 15 kg | 12 | |
| 15 – 20 kg | 25 | |
| 20 – 25 kg | 75 | |
| 25 – 30 kg | 85 | |
| 30 – 35 kg | 100 | |
| 35 – 40 kg | 100 | |
| > 40 kg | 100 |
The load rating tables can be fully customized in the KIM-LHC report settings. You can also enable the 0 – 3 kg weight category if it is relevant to your assessments. Custom tables are stored per gender and persist across sessions.
4 Load Handling
Load Handling assesses how symmetrically the load is held. Motionprint Ergo determines this automatically by measuring the lateral and vertical asymmetry between the left and right hand positions relative to the pelvis. A spatial threshold of 100 mm is applied, combined with a duration threshold of 50% of the lifting task to distinguish temporary from predominant one-handed or asymmetric handling.
| Points | Condition | |
|---|---|---|
0 |
Load is handled with both hands and symmetrically | |
2 |
Load is handled temporarily with one hand and/or asymmetrically, uneven load distribution | |
4 |
Load is handled predominantly with one hand or with an unstable load centre |
5 Body Posture Score
The body posture score is determined from the combination of the worker's start posture (at the beginning of the lifting task) and finish posture (at the end). Motionprint Ergo classifies these automatically from the motion capture data using biomechanical features derived from joint angles in the recording.
Ten posture classes are defined, ranging from fully upright to highly strained. The score is determined by the combination of the two postures observed at the beginning and end of the lifting task. The order is interchangeable — the same score applies regardless of which posture occurs at start or finish. The greater the gap between posture classes, the higher the score:
| Score | Start/Finish | Finish/Start | |
|---|---|---|---|
0 | Standing straight | Standing straight | |
3 | Standing straight | Slightly bent back | |
5 | Slightly bent back | Medium bent back | |
7 | Standing straight | Bended back | |
9 | Standing straight | Squat low | |
10 | Slightly bent back | Bended back | |
13 | Slightly bent back | Squat low | |
15 | Bended back | Bended back | |
18 | Bended back | Squat low | |
20 | Squat low | On knees |
6 Additional Points (Body Posture)
On top of the base body posture score, additional points are added for specific posture conditions detected during the lifting task. The Total Body Score is therefore:
Four conditions are evaluated, all measured automatically from motion capture data:
Trunk twisting / side-bending
Detects whether the trunk is significantly rotated or laterally bent during the task. The threshold is 20° for both lateral bending and trunk twisting.
| Points | Frames exceeding threshold | |
|---|---|---|
0 | < 5% of frames | |
1 | 5 – 25% of frames | |
3 | > 25% of frames |
Load distance to body
Detects whether the hands are positioned more than 170 mm from the body — increasing lever arm forces on the spine.
| Points | Frames exceeding threshold | |
|---|---|---|
0 | < 5% of frames | |
1 | 5 – 25% of frames | |
3 | > 25% of frames |
Hands between elbow and shoulder height
Detects whether the hands are working in the elevated zone between elbow and shoulder height during the task.
| Points | Frames in elevated zone | |
|---|---|---|
0 | < 5% of frames | |
0.5 | 5 – 25% of frames | |
1.0 | > 25% of frames |
Hands above shoulder
Detects highly elevated hand positions — above shoulder height — which significantly increase shoulder and spinal loading.
| Points | Frames above shoulder | |
|---|---|---|
0 | < 5% of frames | |
1 | 5 – 25% of frames | |
2 | > 25% of frames |
7 Unfavorable Working Conditions
Six environmental and task condition factors contribute additional points to the assessment. These reflect conditions that increase musculoskeletal strain beyond what load, posture, and frequency alone capture. Four of the six factors are entered manually on the input page; hand/arm movement and difficulties holding/carrying are derived automatically from motion capture data.
| Factor | Scoring | Source |
|---|---|---|
| Hand/arm movement (wrist deviations) | 0, 1, or 2 — based on wrist flexion >75°, extension >60°, ulnar deviation >30°, radial deviation >15°, pronation >60°, supination >60°, using the same 5% / 25% frame thresholds | Derived automatically from motion capture |
| Force transfer / force application | 0, 1, or 2 — Easy (0): stable grip points, non-slip surfaces, balanced weight; Restricted (1): handles or surfaces that reduce contact quality, requires higher holding forces or work gloves; Hindered (2): slippery, soft, or sharp edges, missing or poor grips, uneven weight distribution | Manual entry |
| Adverse ambient conditions | 0 or 1 — No (0): comfortable temperature and humidity, dry stable footing with good visibility; Yes (1): poor visibility, strong drafts, standing water, ice, mud, or slippery surfaces | Manual entry |
| Spatial conditions | 0, 1, or 2 — Good (0): working area ≥ 1.5 m² with free room to move, clean flat floor; Restricted (1): working area < 1.5 m², floor incline up to 5°, load must be positioned precisely; Unfavorable (2): very confined space with insufficient headroom, floor very dirty, uneven, rough, with steps or potholes | Manual entry |
| Difficulties holding / carrying | 0, 2, or 5 — derived from the task's frame range (hold duration) and cumulative horizontal pelvis displacement (carrying distance): load held > 10 s or carried > 5 m scores 5; held 5 – 10 s or carried 2 – 5 m scores 2; otherwise 0 | Derived automatically from motion capture |
| Impairing clothing | 0 or 1 — No (0): normal work clothing that does not restrict movement; Yes (1): heavy protective equipment, hazmat suits, or bulky clothing restricting movement | Manual entry |
The Unfavorable Conditions Score is the sum of all six factors: ≤ 4 · 5 – 9 · ≥ 10.
8 Work Organization
The Work Organization score reflects the quality of task scheduling and rest provisions. It is entered manually on the input page.
| Points | Level | |
|---|---|---|
0 |
Good — physical tasks vary often throughout the day (including different types of workload), with no prolonged periods of high exertion in any single task. | |
2 |
Restricted — tasks change only occasionally, with some stretches of repeated high exertion in one type of work. | |
4 |
Unfavorable — very little variation, with frequent, repeated peaks of high exertion in the same task during the working day. |
9 Time Rating
The Time Rating is a multiplier between 1 and 10 that reflects how frequently the lifting task is performed during a full work shift, expressed in cycles per day. In Motionprint Ergo, frequency is calculated automatically: the user enters the total working hours or minutes, and the app derives the cycle duration from the trimmed recording length and the number of defined lifting tasks.
The resulting frequency maps to a Time Rating of ×1 (≥ 5/day), ×1.5 (≥ 20), ×2 (≥ 50), ×2.5 (≥ 100), ×3 (≥ 150), ×3.5 (≥ 220), ×4 (≥ 300), ×5 (≥ 500), ×6 (≥ 750), ×7 (≥ 1000), ×8 (≥ 1500), ×9 (≥ 2000), or ×10 (≥ 2500 cycles/day).
The Time Rating is the same for all tasks in the assessment — it reflects the overall shift workload, not the frequency of individual lifting tasks. The cycle duration is computed from the total recording length divided by the number of defined tasks.
10 Multi-Task Assessments
When a worker performs more than one distinct lifting movement within a recording, Motionprint Ergo supports defining multiple lifting tasks. Each task has its own frame range and load weight, and is scored independently for Load Rating, Load Handling, Total Body Score, and the automatically derived unfavorable working conditions (hand/arm movement and difficulties holding/carrying). The manually entered conditions — force transfer, adverse ambient conditions, spatial conditions, impairing clothing, and work organization — are shared across all tasks.
The results page provides a task selector to switch between individual task results. When multiple tasks exist and the averaged overview is enabled in the KIM-LHC settings, the app also computes an averaged overview that aggregates scores across all tasks, giving a holistic view of the overall task demand for the full recording.
The KIM-LHC method does not define a formal composite index formula for multi-task aggregation. Task scores are independent and an averaged overview is provided when enabled in the KIM-LHC settings.
11 Implementation in Motionprint Ergo
Motionprint Ergo implements the full KIM-LHC method in a dedicated processing pipeline that applies BAuA posture thresholds and scoring criteria to the motion capture data frame by frame, across all defined lifting tasks.
Calculation workflow
Body posture, trunk angles, hand positions, wrist angles, and load handling asymmetry are extracted automatically from motion capture data. Manual inputs — load weight category, working conditions, work organization, working hours, gender, and the trim range (start/end frame) defining the active portion of the recording — are entered in the assessment setup panel and passed to the processing pipeline.
Each scoring component is computed per lifting task. The body posture is classified using weighted joint angle matching against the 10 reference postures. Additional points for trunk twisting, load distance from body, and hand height are determined from frame-by-frame analysis using percentage-of-frames thresholds. Load handling asymmetry, hand/arm movement (wrist deviations), and difficulties holding/carrying are also derived automatically per task. The load rating is looked up from the weight category and gender.
All component scores are summed into Rating Points, then multiplied by the Time Rating to produce the Total Score. For multi-task assessments, individual scores and (if enabled) an averaged overview are computed across all defined tasks.
Results are presented across three report tabs. Score overview shows a visual summary of all components with color-coded risk indicators for each: Load Rating, Load Handling, Total Body Score, Unfavorable Working Conditions, Work Organization, and the final Total Score. In-depth analysis lets you explore per-frame score graphs, critical moments, and a synchronized 3D viewer to see exactly which frames and postures are driving the score. Findings (if enabled in settings) provides editable sections for documenting observations.