"A significant number" of parents of junior athletes have a negative impact on their child's development, suggests research published ahead of print in the British Journal of Sports Medicine.
The findings are informed by a national survey of 132 professional junior tennis coaches in the US, which looked at the role parents play in the successes of their sporting offspring. The coaches had all spent an average of 17 years in the business.
The survey included 200 individual items, covering nine categories of question. Coaches were asked to score the positive or negative impact of parental involvement in their child's sporting performance, using validated scales.
The coaches felt that over half of parents had a positive influence on their children in respect of financial and practical support and instilling good behaviours, such as hard work and a positive approach.
But they also considered more than a third of parents as harmful to their child's development.
The most common problems involved excessive focus on winning, unrealistic expectations, coaching their own child, criticising their child, and excessive pampering, all of which scored around 3.5 out of a maximum of 5 points.
When asked to rate the level of seriousness of these problems, the coaches scored overemphasis on winning, criticism, and lack of emotional control the highest, each attracting nearly 4 out of 5 points.
The authors says that parents may find it difficult to put winning in perspective, and so criticise, pressurise, or push their children inappropriately in a bid to motivate them.
"Although many parents do an excellent joband contribute positively to their child's development, the experienced coaches felt that a significant number unknowingly interfere with their child's development," conclude the authors.
"This is not surprising given the fact that sport parents receive little or no training about how to help their child develop and are exposed to a youth sports environment that is increasingly professional," they add.