Error and variability in learning and balance

Summary

Good balance control is essential for almost everything you do. Balance control prevents you from falling when you are sitting or standing still and when you are moving around your environment (e.g. walking). Good balance control also helps to prevent a fall after a loss of balance (e.g. a trip or a slip). Even though balance involves the whole body, researchers often argue it is a fine movement skill. This means that any movements and adjustments made to maintain balance are very small and, therefore, variability of movements when balancing is small. It is believed that large variability indicates error and that the person has ‘bad’ balance. If errors go uncorrected they can lead to falls.

Consider two people learning a new movement skill. The first is a toddler learning to take her first steps. The second is an acrobat learning to walk on a tightrope. Balance is tricky for the novice walker, and the toddler will surely fall hundreds, thousands, (or more!) times before she masters the art of walking, but the acrobat can’t afford to make such mistakes. Even with safety nets and harnesses that are surely required when learning such a treacherous skill, the acrobat still perceives the threat of a fall, which would cause him to limit errors. Despite abundant errors in the first scenario, and limited errors in the second scenario, both learners can achieve proficiency in these skills. This is something of a paradox.

Researchers who study how people learn new movement skills, such as a tennis serve, have studied how errors made during the learning process influence how well the person learns the skill. One group of researchers argues that errors interfere with the person’s ability to learn the ‘correct’ movement pattern. These researchers have found that minimizing errors during practice can improve the person’s ability to learn the movement skill. Another group of researchers believe that trial and error is essential for learning. When errors are made during practice, the person learns how to ‘solve’ these errors, and learns the movement better than if they made fewer errors.

This research will investigate variability and error in balance control. In particular, we will look at how errors made when practicing influence how well someone learns a balance skill. This work is important because errors in balance control can lead to falls and injuries. Such consequences of errors are not necessarily present when learning other movement skills. The results of this research will apply to anyone learning a movement skill that requires balance, even those toddlers learning the seemingly simple skill of walking.


Funding

Natural Sciences and Engineering Research Council of Canada, Discovery Grant (2014-2020)

Ministry of Research and Innovation, Early Researcher Award (2015-2020)

The Drummond Foundation (2014)


Trainees

Amir Boroomand-Tehrani (MSc student)

Jacqueline Nestico (MSc student)

Andrew Huntley (post-doctoral fellow)

Chris McCrum (former visiting scholar)

Suluxshiga Jeyendran (former undergraduate co-op student)

Laksh Gill (former MSc student)

Jyoti Mann (former undergraduate co-op student)

Cynthia Campos (former undergraduate co-op student)

Bimal Lakhani (former post-doctoral fellow)

Rosh Rajachandrakumar (former MSc student)

Alison Schinkel-Ivy (former post-doctoral fellow)

Shajicaa Sivakumaran (former undergraduate co-op student)

I am currently recruiting new trainees to work on this project


Rajachandrakumar R, Mann J, Schinkel-Ivy A, Mansfield A. Exploring the relationship between centre of mass and centre of pressure variability and stability. Gait and Posture. 2018;63:254-259. doi:j.gaitpost.2018.05.008

Sivakumaran S, Schinkel-Ivy A, Masani K, Mansfield A. Relationship between margin of stability and deviations in spatiotemporal gait features in healthy young adults. Human Movement Science. 2018;57:366-373. doi:10.1016/j.humov.2017-09.014

Mansfield A, Aqui A, Fraser JE, Rajachandrakumar R, Lakhani B, Patterson KK. Can augmented feedback facilitate learning a reactive balance task among older adults? Experimental Brain Research. 2017;235(1):293-304. doi:10.1007/s00221-016-4790-6

Lakhani B, Mansfield A. Visual feedback of the centre of gravity to optimize standing balance. Gait and Posture. 2015;41(2):499-503. doi:10.1016/j.gaitpost.2014.12.003

Papers