“Native” Joint Versus “Step” Joint: There Is More Way from Data Collection to Comprehensive Conclusion

Mehdi Nematimoez

doi:10.20944/preprints202512.1041.v1

Submitted:

10 December 2025

Posted:

12 December 2025

You are already at the latest version

Abstract

The human body consists of multiple joints with many degrees of freedom that open the context for biomechanical interventions in the form of recommendations and feedback, with the purpose of improving performance, reducing the risk of injuries, and so forth. These interventions sometimes involve loading trade-offs between joints or loading redistribution. Removing the load from one joint or segment (“native” joint) and transferring it to another joint (“step” joint) seem to need more consideration. Therefore, the aim of the current paper is to highlight the necessity of scientific communication from data collection to conclusions in the form of recommendations, presentations, and publications. The tendency to focus on specific joints and develop expertise hides the trade-off between joint loads, and sometimes, recommendations or feedback on the basis of biomechanical loading simply shift the risk of injury. To address this concern, several approaches are suggested, including improved marker sets, dataset availability, departmental diversity, research team collaboration, and the sharing of conferences and sessions.

Keywords:

biomechanics

;

joint

;

digital shearing

;

research team

;

diversity

Subject:

Biology and Life Sciences - Other

Introduction

The human body consists of multiple joints, and the health and proper function of these joints are required for smooth and optimal movement, which distinguishes humans from some human-made robots. These characteristics of the human body provide an opportunity for the investigation of many fields of study, such as biomechanics, and for the development of many departments worldwide that aim to improve health and quality of life. The complexity of movement has led to the growth of specialized and focused research teams, whether as part of a department or as independent departments. Additionally, opportunities for collaboration, communication, and diversity among them can be observed through collaborative projects (https://spexor.eu/publications/), conference participation, and publications; hence, there is a question: is it working perfectly?

Research has shown that any changes in the normal function of any joint may be reflected in the biomechanical function of other joints under the supervision of the neural control system (Panjabi, 1992). In the most seemingly simple case, the control system tries to maintain the lowest energy expenditure while standing by reducing muscle activity, specifically in the spine, as a subsystem of stability through compensatory spinal curve adjustments to provide standing balance with as little physiological cost as possible (Schwab et al., 2010).

The action of the control system is more complicated in dynamic situations than in standing and requires more sophisticated control and integrity of the subsystems, which could occur during athletic performance, which requires developed motor control (Mercier et al., 2020). Nevertheless, continuous exposure of human joints to overloading and repetitive loading reduces the chance of the control system providing enough safety margin to reduce the risk of injury in these conditions. Therefore, this opens the context for biomechanical interventions in the form of recommendations (Waters et al., 1993), feedback and developing exoskeletons (Baltrusch et al., 2020; Gull et al., 2020), with the purpose of improving performance (Ericksen et al., 2013), reducing the risk of injuries (Oppici et al., 2021; Punt et al., 2020), and so forth.

These interventions sometimes involve loading trade-offs between joints or loading redistribution. For example, the lumbar spine and knee are joints at high risk of causing disability, as low back pain and osteoarthritis are among the 14 leading causes of disability among all diseases, and they are the first and second most common musculoskeletal diseases, respectively, leading to years lived with disability (Diseases & Injuries, 2024). There are paradoxical recommendations for managing manual handling of biomechanical loads, which makes it difficult to reach conclusions about safety in the workplace. For lifting and lowering, although there is controversy in the literature about safe styles (von Arx et al., 2021), there is a recommendation to pick up the load by bending the knees (Boocock et al., 2024; Prisco et al., 2024), e.g., the squat technique, whereas squatting has been identified as an occupational risk factor for knee osteoarthritis (Yucesoy et al., 2015), and only a few studies consider this trade-off (Gallagher et al., 2011). Indeed, removing the load from one joint or segment (“native” joint) and transferring it to another joint (“step” joint) seem to need more consideration. Therefore, the purpose of the current paper is to highlight the necessity of scientific communication from data collection to conclusions in the form of recommendations, presentations, and publications.

Discussion

In the new era of digital and information growth and the need for a deep understanding of human movement biomechanics, there is a tendency to focus on specific joints and develop expertise. Despite the benefits of this expertise, a lack of communication among researchers working on the different joint sometimes leads to joint-loading trade-offs that have not been deeply considered and makes it difficult to predict the loading of other joints as secondary joints. Additionally, this prespective gives researchers the confidence to ignore some important parts of the research protocol for comprehensive evaluation of movement biomechanics by focusing on a single joint or body part. This results in researchers effectively examining only part of the body when organizing research teams, departments, or even laboratories (e.g., lower extremities, upper extremities, and spine). This limitation becomes more critical in highly dynamic movements, such as those studied in sport biomechanics.

There are other possible reasons for the single-joint perspective, such as lack of expertise, limited resources, time savings, and attracting participants to experimental studies by reducing preparation protocols for attaching markers and electrodes to the body. Although standard marker sets are available from commercial biomechanics companies, they are usually not sufficient for detailed analysis of certain body parts, such as the spine, which has a multisegmented structure (Ignasiak et al., 2017; Nematimoez et al., 2025; Schmid et al., 2022; Seerden et al., 2019; Zwambag et al., 2019). A full and extended marker set could also help support the development of algorithms for predicting segmental motion, which would be required for markerless technologies (Colyer et al., 2018) that may, in the future, address marker set challenges (Nogueira et al., 2025).

“Step” joint perspective comes at the cost of losing information from other joints that may have valuable data. It seems necessary to emphasize that while expertise and focused research have invaluable benefits, the lack of communication and collaboration leads to the loss of resources, time, and, most importantly, valuable information that other teams and laboratories may not have the ability to measure. Such as human movement without abnormal joints, it seems that diverse research teams within a department or developed collaborations among diverse teams lead to smoother research progress, and higher productivity.

Future Directions

There are several possible solutions to this challenge that could be invaluable: first, fully detailed marker sets for measurements can be used, especially in the case of dynamic experiments, and freely available datasets can be provided. Second, partnering with research teams or groups that are related to our “step” joints. Third, providing dedicated conferences and sessions for communication to address biomechanical challenges related to recommendations, feedback options, and developing exoskeleton for managing high-risk loading conditions.

Conclusions

The tendency to focus on specific joints and develop expertise hides the trade-off between joint loads, and sometimes, recommendations, feedback, or developing exoskeleton just shift the risk of injury to “step” joints. To address this concern, several approaches are suggested, including improved marker sets, dataset availability, departmental diversity, research team collaboration, and the sharing of conferences and sessions.

Data Availability Statement

Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.

References

Baltrusch, S. J.; van Dieen, J. H.; van Bennekom, C. A. M.; Houdijk, H. Testing an Exoskeleton That Helps Workers With Low-Back Pain: Less Discomfort With the Passive SPEXOR Trunk Device. IEEE Robotics & Automation Magazine 2020, 27(1), 66–76. [Google Scholar] [CrossRef]
Boocock, M.; Naudé, Y.; Saywell, N.; Mawston, G. Obesity as a risk factor for musculoskeletal injury during manual handling tasks: A systematic review and meta-analysis. Safety Science 2024, 176. [Google Scholar] [CrossRef]
Colyer, S. L.; Evans, M.; Cosker, D. P.; Salo, A. I. T. A Review of the Evolution of Vision-Based Motion Analysis and the Integration of Advanced Computer Vision Methods Towards Developing a Markerless System. Sports Med Open 2018, 4(1), 24. [Google Scholar] [CrossRef]
Diseases, G. B. D.; Injuries, C. Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet 2024, 403(10440), 2133–2161. [Google Scholar] [CrossRef]
Ericksen, H. M.; Gribble, P. A.; Pfile, K. R.; Pietrosimone, B. G. Different modes of feedback and peak vertical ground reaction force during jump landing: a systematic review. J Athl Train 2013, 48(5), 685–695. [Google Scholar] [CrossRef] [PubMed]
Gallagher, S.; Pollard, J.; Porter, W. L. Electromyography of the thigh muscles during lifting tasks in kneeling and squatting postures. Ergonomics 2011, 54(1), 91–102. [Google Scholar] [CrossRef] [PubMed]
Gull, M. A.; Bai, S.; Bak, T. A Review on Design of Upper Limb Exoskeletons. Robotics 2020, 9(1). [Google Scholar] [CrossRef]
Ignasiak, D.; Rueger, A.; Ferguson, S. J. Multi-segmental thoracic spine kinematics measured dynamically in the young and elderly during flexion. Hum Mov Sci 2017, 54, 230–239. [Google Scholar] [CrossRef]
Mercier, M.-A.; Tremblay, M.; Daneau, C.; Descarreaux, M. Individual factors associated with baseball pitching performance: scoping review. BMJ Open Sport & Exercise Medicine 2020, 6(1). [Google Scholar] [CrossRef]
Nematimoez, M.; Bangerter, C.; Von Arx, M.; Liechti, M.; Schmid, S. Gender and body height discriminate spinal movement patterns during lifting and lowering tasks. Ergonomics 2025, 1–13. [Google Scholar] [CrossRef]
Nogueira, A. F. R.; Oliveira, H. P.; Teixeira, L. F. Markerless multi-view 3D human pose estimation: A survey. Image and Vision Computing 2025, 155. [Google Scholar] [CrossRef]
Oppici, L.; Grütters, K.; Garofolini, A.; Rosenkranz, R.; Narciss, S. Deliberate Practice and Motor Learning Principles to Underpin the Design of Training Interventions for Improving Lifting Movement in the Occupational Sector: A Perspective and a Pilot Study on the Role of Augmented Feedback. Frontiers in Sports and Active Living 2021, 3. [Google Scholar] [CrossRef]
Panjabi, M. M. The stabilizing system of the spine. Part I. Function, dysfunction, adaptation, and enhancement. J Spinal Disord discussion 397. 1992, 5(4), 383–389. [Google Scholar] [CrossRef]
Prisco, G.; Romano, M.; Esposito, F.; Cesarelli, M.; Santone, A.; Donisi, L.; Amato, F. Capability of Machine Learning Algorithms to Classify Safe and Unsafe Postures during Weight Lifting Tasks Using Inertial Sensors. Diagnostics (Basel) 2024, 14(6). [Google Scholar] [CrossRef]
Punt, M.; Nematimoez, M.; van Dieen, J. H.; Kingma, I. Real-time feedback to reduce low-back load in lifting and lowering. Journal of Biomechanics 2020, 102, 109513. [Google Scholar] [CrossRef]
Schmid, S.; Connolly, L.; Moschini, G.; Meier, M. L.; Senteler, M. Skin marker-based subject-specific spinal alignment modeling: A feasibility study. Journal of Biomechanics 2022, 137, 111102. [Google Scholar] [CrossRef] [PubMed]
Schwab, F.; Patel, A.; Ungar, B.; Farcy, J. P.; Lafage, V. Adult spinal deformity-postoperative standing imbalance: how much can you tolerate? An overview of key parameters in assessing alignment and planning corrective surgery. Spine (Phila Pa 1976) 2010, 35(25), 2224–2231. [Google Scholar] [CrossRef]
Seerden, S. F. L.; Dankaerts, W.; Swinnen, T. W.; Westhovens, R.; de Vlam, K.; Vanwanseele, B. Multi-segment spine and hip kinematics in asymptomatic individuals during standardized return from forward bending versus functional box lifting. J Electromyogr Kinesiol 2019, 49, 102352. [Google Scholar] [CrossRef]
von Arx, M.; Liechti, M.; Connolly, L.; Bangerter, C.; Meier, M. L.; Schmid, S. From Stoop to Squat: A Comprehensive Analysis of Lumbar Loading Among Different Lifting Styles. Front Bioeng Biotechnol 2021, 9, 769117. [Google Scholar] [CrossRef] [PubMed]
Waters, T. R.; Putz-Anderson, V.; Garg, A.; Fine, L. J. Revised NIOSH equation for the design and evaluation of manual lifting tasks. Ergonomics 1993, 36(7), 749–776. [Google Scholar] [CrossRef]
Yucesoy, B.; Charles, L. E.; Baker, B.; Burchfiel, C. M. Occupational and genetic risk factors for osteoarthritis: a review. Work 2015, 50(2), 261–273. [Google Scholar] [CrossRef] [PubMed]
Zwambag, D. P.; Beaudette, S. M.; Gregory, D. E.; Brown, S. H. M. Distinguishing between typical and atypical motion patterns amongst healthy individuals during a constrained spine flexion task. Journal of Biomechanics 2019, 86, 89–95. [Google Scholar] [CrossRef] [PubMed]

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