Related Experiment Video
Updated: Mar 12, 2026
Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
Differences in motor variability among individuals performing a standardized short-cycle manual task.
Jonas Sandlund1, Divya Srinivasan2, Marina Heiden2
1Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, SE-901 87 Umeå, Sweden; Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, Faculty of Health and Occupational Studies, University of Gävle, SE-801 76 Gävle, Sweden.
Individuals consistently show unique patterns of motor variability (MV) during repetitive tasks. This suggests MV could be a personal trait influencing the risk of musculoskeletal disorders in occupational settings.
Area of Science:
- Biomechanics
- Occupational Health
- Human Factors Engineering
Background:
- Motor variability (MV) is implicated in the risk of developing musculoskeletal disorders (MSDs) during repetitive occupational tasks.
- Understanding individual differences in MV is crucial for assessing MSD risk.
Purpose of the Study:
- To investigate if individuals exhibit consistent differences in motor variability during a standardized manual task.
- To determine if motor variability is a stable personal trait.
Main Methods:
- 14 healthy subjects performed a pipetting task over three separate days.
- Arm kinematics (shoulder and elbow) were recorded.
- Cycle-to-cycle variability was quantified using standard deviations and analyzed with principal component analysis (PCA) and random effects models.
Main Results:
- Significant and consistent between-subjects differences in motor variability were observed.
- Consistent within-subject differences in motor variability across different days were also found.
- These findings support motor variability as a potential personal trait.
Conclusions:
- Motor variability appears to be a consistent personal trait.
- Further research is needed to confirm consistency across different tasks.
- Consistent motor variability may serve as a risk factor for fatigue and MSDs in repetitive occupational work.
