In many cases, injuries sustained while playing can cause long-term damage. In addition to neurological damage caused by hits to the head, injuries to the mid and lower body can force players to retire or lead to nagging ailments in later life. Various methods have been used to reduce injuries in football, including rule changes such as the abolition of large wedge formations; a sharp decline in cervical spine injuries since the 1970s has been attributed to rule changes that altered blocking and tackling techniques. More recently, rule changes to protect players from head injuries have been instituted. Equipment like the football helmet and pads are used to give players a level of protection from injuries, while other factors such as cleat size are used to minimize the risk of injuries due to field condition.