There are over 1 million registered soccer players in Canada.  Of those, over 80% are youth soccer players (between the ages of 5-17).  These numbers are a great example of how much the game as grown in this country over the past few decades, especially at the grass roots level.   One of the challenges that have accompanied this growth, however, is that the increased numbers of players have been organized and grouped according only to their chronological age (typically in Canada, this grouping is done based on the year in which the players are born).  On the surface, grouping players according to their chronological age or birth year seems fair – after all, this is the same way that the Canadian educational system groups its students.     Unfortunately, in both the youth sports / youth soccer systems, as well as in the educational system, grouping children based simply on the year and month in which they were born will not lead to optimal development, and many of these children will end up getting left behind.

There are two different “ages”, or methods, by which a child’s development can be determined.  The first, as mentioned above, is their chronological age (determined by their birth year); the second, and perhaps more important one, is their developmental age.   Developmental age can be determined by taking into account a variety of factors, including chronological age, gender, standing height, sitting height, and body mass.  A specific formula is then used, taking all of these factors into account, to determine the child’s age of Peak Height Velocity (or “PHV” for short).  A child’s age of Peak Height Velocity is defined as the age at which they will reach, or have reached, their maximum rate of growth.  On average, girls will reach their age of Peak Height Velocity between the ages 10-13, and boys will reach it between the ages of 12-15.     Reaching age of Peak Height Velocity typically occurs during the “growth spurt” that accompanies puberty, and thus, it coincides with increases in height but also in several other developmental characteristics, including increased production of anabolic hormones like testosterone and growth hormone, and accelerated development of the central nervous system, including the brain and spinal cord.  Thus, children who reach age of Peak Height Velocity earlier in their life will be at a significant advantage in sports including soccer, due to advanced physical, physiological, and cognitive development.

Simple examination of the average range in age in which boys and girls reach Peak Height Velocity (and thus the range of their actual developmental age) provides clear evidence of the problem with grouping young children together simply based on their chronological age.  For example, if the average age range for girls to reach Peak Height Velocity is 10-13, then there is a chance that any girls’ soccer team in any specific age category (U12, for instance) will be comprised of girls who have an actual developmental age of 10 and are playing, training and competing with girls who have an actual developmental age of 14.  This disparity in developmental age can present a significant problem to youth soccer coaches as well as their Club/Academy directors, one of whose main jobs is to identify talented players and place them in appropriate high performance programs.  There is likely no soccer coach in Canada who would accept forcing a 10 year-old girl to play for a team and compete in a league against 14 year-old girls, yet, if coaches in Canada do not know the actual developmental age of their players, this might actually already be occurring without their knowledge.

The best way for youth soccer coaches and Club/Academy directors to ensure parity between the developmental ages of their players is to simply assess and determine all of their players’ age of Peak Height Velocity.  Once all players in a given team or age category have had their age of Peak Height Velocity determined, specific decisions regarding specific players can be made based on their developmental age versus their chronological age.  For example, in the aforementioned girls’ U12 team, perhaps some players who are determined to be 2-3 years developmentally behind the average for their team could be moved to a younger aged team.  Conversely, if there are a few players who are 2-3 years developmentally ahead of the team average, they could be moved up to an older aged team.  Of course, there are several other factors for coaches to consider besides developmental age when making decisions about player identification and selection, including players’ technical ability, tactical awareness and knowledge of the game, and their psychological traits and personality.  If developmental age of players is ignored, especially in high performance environments, then there is a good chance that some talented players will be left behind simply because they reached their age or Peak Height Velocity later than the average for their team.

I’d love to hear your thoughts about this topic.  Drop me a line here to get the conversation started.

In soccer, the technique of striking a ball with the instep of the foot has always seemed to be more of an art form than an exact science.  Players who have mastered this technique (a few modern examples include David Beckham, Andrea Pirlo, and Zlatan Ibrahimovic) have no doubt spent thousands of hours practicing it, and as a result have developed their own slightly unique ball striking style.  While this style may differ from player-to-player, a few biomechanical constants in the technique remain the same.  Because a the cross-bar on a regulation size soccer goal is only 2.44 metres high, keeping the ball low when striking it is a critical component to the technique.  Expert ball strikers – even if they strike the ball with a slightly differing technique – can strike with power and accuracy, while at the same time keeping the ball low enough to stay under the 2.44 metre cross-bar height.

Like many other soccer players who grew up in Canada, I was first introduced to ball striking technique from house league and rep coaches at a very early age.  And, like many other Canadian players, I was taught from my coaches that in order to keep the ball low when striking it, I had to “keep my body over the ball.”  On the surface, this coaching advice seems to make sense – after all, most of the time, especially with young players, if they keep their body over the ball while striking it, the ball is likely to stay lower than if they lean back while striking it.  It is also part of our natural instincts as humans and as athletes to assume that the way we were taught to execute a technique (in this case, ball striking with the instep of the foot) is the correct way, especially if we are able to achieve the desired result through this execution (in this case, keeping the ball low when striking it).

A closer look into the biomechanics of ball striking, however, reveals that keeping the body over the ball has no relevance whatsoever to the height at which the ball will travel when it is struck.  This is because the height that a ball reaches during an instep strike is related only to the point on the ball at which the foot makes contact with the ball when it is struck.  If the ball is struck on the top half (slightly above the midline of the ball) it will stay low, regardless of the body position while striking.  Similarly, if the ball is struck on the bottom half (below the midline of the ball) it will travel upwards, also regardless of the body position while striking.  Thus, a coach who wishes to teach a player how to keep the ball low when striking with the instep of the foot needs only to focus on ensuring the player makes contact with the top half of the ball.  There is no more need to tell a player to “keep your body over the ball.”

The elimination of the “body over the ball” kicking technique has other advantages as well.  In a comprehensive review of instep kicking mechanics, Ismail et. al. (2010) determined that power in the instep strike is maximized in part through maximizing the range of motion at the hip of the kicking leg.  This is because a greater range of motion at the hip allows the thigh and shin to travel – or accelerate – over a greater distance, and as a result of this greater acceleration, the power generated in the leg when contacting the ball will increase.  Thus, a body position that is open, with an upright or slightly extended torso when contacting the ball, will allow for maximal range of motion at the hip joint of the kicking leg.  Conversely, bending forwards or hunching over to keep the upper body “over the ball” has the exact opposite effect – that is, it restricts the range of motion at the hip of the kicking leg.

As mentioned previously, striking the ball with the instep of the foot is still very much an art form, so individual differences in ball striking technique may still exist between different players.  Coaches who wish to teach players how to maximize power while at the same time keeping the ball low when striking with the instep, however, should avoid instructing players to “keep their body over the ball.”  Instead, coaches should follow basic biomechanics principles, and instruct players to keep an upright, “open” body position, and make contact with the top half of the ball, in order to maximize power and keep the ball low when striking.

I’d love to hear your thoughts about this topic.  Drop me a line here to get the conversation started.