According to WeightTraining.com, weight lifting is a safe way to strengthen bones and can only result in stunted growth if injuries to the growth plate occur. Proper weight lifting with correct technique does not stunt growth or make an individual shorter.
WeightTraining.com states that growth plates are found on the ends of bones in children and adolescents. Growth plates are areas of tissue around which bones grow. If a growth plate is damaged by a falling weight, it may affect the length of the bone that grows around it. Therefore, injuries to a growth plate can possibly result in situations where one leg grows shorter than the other. However, the growth plate would have to be seriously damaged; proper technique and form minimize the possibility of something like this occurring.