Background
     College Soccer players suffer repetitive impact 
      to the head throughout their season through 
      heading of a soccer ball
     Both in practice and in games they must strike 
      the ball with their head from defensive and 
      offensive positions
     This exposes them to multiple impacts to the 
      head throughout their season
     Depending on position some players will head 
      the ball more than others
                      Background
     How repetitive heading of a ball throughout a 
      season may affect a player's performance on 
      Neuropsychological testing is unclear
     There is much ongoing debate as to the effect of 
      heading a ball on a soccer player's long term 
      health
     It has been suggested that soccer players 
      should wear protective head gear, especially at 
      the youth level to protect a player from 
      developing Neurocognitive dysfunction 
      secondary to heading
                Headgear in Soccer
     Mainly marketed to Youth Soccer players under 
      the age of 12, where the occurrence of heading 
      is significantly decreased, as compared to 
      higher levels of play
     Many of the headers at this level occur off the 
      bounce
     Studies have shown that the peak force of 
      impact from a soccer ball was reduced by 112% 
      or 400 N
     Clinical Efficacy remains to be seen
            Specifications of the Ball
     Law 2 of the game, as per FIFA's Laws of the 
      Game, states :
     Circumference : 27-28 in. (68-70 cm)
     Weight : 14-16 oz. (410-450 grams)
     Pressure : 8.5-15.6 psi (59-108 kPa)
                Mechanics of Impact
     The highest velocity balls a player might head 
      voluntarily are as follows : 
     Goalkeeper's Punt : 70km/h or 43 mph
     Goalkeeper's Dropkick : 85 km/h or 53 mph
     Goal Kick : 85 km/h or 53 mph
     Shot towards goal from a striking position : 119 
      km/h or 74 mph