In sports, the pursuit of ideal technique and consistent movements is a common goal. There is a widespread belief that consistent movements lead to consistent results. However, variability in human movement is inevitable because the human motor system is a highly complex mechanism influenced by numerous interacting variables (1,2).
For many years, variation or “irregularity” in movements was seen as something negative, often interpreted as error or failure in motor control. However, studying variability is complex, and with advancements in data analysis and assessment technology, recent studies have started to view variability differently. In fact, variability in movements is often considered functional and positively correlated with performance (3).
What Do the Studies Show?
1. Busquets et al. (2016): Variability in Artistic Gymnastics
Busquets and colleagues conducted a study with 113 male artistic gymnasts, dividing them into five groups based on their level of experience. The least experienced group had an average of 3.6 years of experience, while the most experienced group had an average of 14.2 years. Variability during three repetitions of a rotation movement on the high bar was assessed. The study found that less variability in arm-trunk coordination was associated with greater experience. However, for most other components, the results were opposite. For example, greater variability in shoulder and hip angles was correlated with more experienced athletes. According to the authors, this variability provided athletes with flexibility, facilitating connections to other movements and dismounts (4).
2. Barris et al. (2014): Variability in Springboard Diving
In a study on springboard diving, Barris and colleagues followed athletes over 12 weeks. They observed that variability increased at the end of the training period, along with improvements in technical performance, as reflected in the judges’ scores. This suggests that as the athletes improved, their variability became functional, allowing them to explore the environment and adapt more flexibly to adjustments (5).
3. Glanzer et al. (2019): Variability in Baseball Pitchers
Glanzer and colleagues examined variability among baseball pitchers. They found that consistency in pitching patterns led to greater accuracy. However, one aspect of variability, shoulder movement during horizontal abduction (performed alongside trunk rotation), positively correlated with pitch accuracy (6).
4. Stannard and Robins (2013): Variability in Basketball Players
Stannard and Robins studied basketball players, dividing them into three groups based on experience. Athletes performed a movement with the ball and attempted a shot from 4.25 meters. The results showed that beginners and advanced players had the most variation in movement patterns, while intermediate players exhibited the least variability (7).
Variability Is More Complex Than We Imagined
Numerous studies suggest that variability can be functional. Two main perspectives exist:
- Reduction Hypothesis: Variability decreases with practice.
- U-shaped Development: Variability is high (non-functional) for beginners, then decreases as movements stabilize, and increases again (functional variability) in experts, providing the system with greater flexibility (3,8).
Take way
Instead of assuming that movement variability is bad, we should embrace variability as a natural part of human movement, recognizing its potential to enhance flexibility, adaptability, and performance. Variability allows the body to explore different movement strategies, reducing the risk of overuse injuries and improving the ability to adjust to environmental and task-specific demands. Rather than striving for rigid consistency, coaches, athletes, and practitioners should focus on fostering functional variability that supports skill development and long-term performance gains. By understanding variability as a tool rather than a flaw, we can better support athletes in achieving sustainable success.
References
1. Preatoni E, Hamill J, Harrison AJ, Hayes
K, van Emmerik REA, Wilson C, et al. Movement variability and skills monitoring
in sports. Sport Biomech. 2013;12(2):69–92.
2. Davids K, Bennet S, Newell K. Movement
System Variability. Human Kinetics; 2006. 364 p.
3. Sternad D. It’s not (only) the mean that
matters: variability, noise and exploration in skill learning. Curr Opin Behav
Sci [Internet]. 2018;20:183–95. Available from: http://dx.doi.org/10.1016/j.cobeha.2018.01.004
4. Busquets A, Marina M, Davids K,
Angulo-Barroso R. Differing roles of functional movement variability as
experience increases in gymnastics. J Sport Sci Med. 2016;15(2):268–76.
5. Barris S, Farrow D, Davids K. Increasing
functional variability in the preparatory phase of the takeoff improves elite
springboard diving performance. Res Q Exerc Sport. 2014;85(1):97–106.
6. Glanzer JA, Diffendaffer AZ, Slowik JS,
Drogosz M, Lo NJ, Fleisig GS. The relationship between variability in baseball
pitching kinematics and consistency in pitch location. Sport Biomech
[Internet]. 2019;00(00):1–8. Available from:
https://doi.org/10.1080/14763141.2019.1642378
7. Stannard R, Robins M. THE EFFECT OF
EXPERTISE ON COORDINATION VARIABILITY DURING A DISCRETE MULTI-ARTICULAR ACTION.
In: 18th annual Congress of the EUROPEAN COLLEGE OF SPORT SCIENCE [Internet].
2013. p. 47–8. Available from:
http://dx.doi.org/10.1016/j.biotechadv.2010.07.003%0Ahttp://dx.doi.org/10.1016/j.scitotenv.2016.06.080%0Ahttp://dx.doi.org/10.1016/j.bbapap.2013.06.007%0Ahttps://www.frontiersin.org/article/10.3389/fmicb.2018.02309/full%0Ahttp://dx.doi.org/10.1007/s13762-
8. Serrien B, Ooijen J, Goossens M, Baeyens
J-P. A Motion Analysis in the Volleyball Spike – Part 2: Coordination and
Performance Variability. Int J Hum Mov Sport Sci. 2016;4(4):83–90.
