Effects of scaling task constraints on emergent behaviours in children's racquet sports performance

Manipulating task constraints by scaling key features like space and equipment is proposed as an effective method for enhancing development and refinement of movement patterns in sport. Despite this, it is currently unclear whether scaled manipulation of task constraints would impact emergent movement behaviours in young children, affording learners opportunities to develop functional movement behaviours. Here, we sought to investigate how scaling task constraints during 8-weeks of mini tennis training shaped emergent movement behaviours, such a backhand stroke development. Two groups, control (n = 8, age = 7.2 ± 0.6 years) and experimental (n = 8, age 7.4 ± 0.4 years), underwent practice using constraints-based manipulations, with more specific affordances for backhand strokes designed for the latter group. To evaluate intervention effects, pre- and post-test match-play characteristics (e.g. forehand and backhand percentages) and measures from a tennis-specific skills test (e.g. forehand and backhand technical proficiency) were examined. Post intervention, the experimental group performed a greater percentage of backhands out of total number of shots played (46.7 ± 3.3%), and a significantly greater percentage of backhand winners out of total backhand strokes observed (5.5 ± 3.0%), compared to the control group during match-play (backhands = 22.4 ± 6.5%; backhand winners = 1.0 ± 3.6%). The experimental group also demonstrated improvements in forehand and backhand technical proficiency and the ability to maintain a rally with a coach, compared to the control group. In conclusion, scaled manipulations implemented here elicited more functional performance behaviours than standard Mini Tennis Red constraints, suggesting how human movement scientists may scale task constraint manipulations to augment young athletes' performance development. Keywords: Scaling task constraints, intervention, tennis, affordances, emergent behaviours