Steve Curnyn is Head of Academy Football Medicine and Science at Hibernian FC Academy. After a fantastic site visit to see behind the scenes at Hibernian FC, he generously accepted a request to write a guest post on growth and maturation in youth footballers and the monitoring and adaptation to their day to day training at Hibernian FC.
GROWTH & MATURITY IN ACADEMY FOOTBALLERS
The key to creating a successful young football athlete is a combination of many factors including training history, match minutes, technical, motor skills, psychological and emotional factors. Physical components such as aerobic capacity, anaerobic power, maximal sprinting, changing of direction and jumping ability are key determinants of performance. In my experience, these factors are massively influenced by maturation status. The foundations for all stages of maturation are full movement competencies.
The key to creating a long-term athletic development (LTAD) model when working amongst youth athletes is determining important points in each individual’s growth and maturation. When working with youth it is key to accurately identify the point of peak height velocity (PHV) and estimated final adult height. PHV is identified as a milestone where a person goes from pre-pubescent to post pubescent. This will involve a significant change in size and stature, due to the fact their growth rate will be faster than any other point in their development. PHV typically occurs at around 90-91% of predicted adult height. We estimate PHV using the Kamis-Roche method by taking height, sitting height, weight and biological parents’ height.
We take this measurements every 8 weeks. This way it ensures the next training cycle can be adjusted accordingly to the individuals needs after each measurement. Typically, the players are identified as being
1. Pre-Puberty less than 85% of predicted adult height
2. Circa-Puberty 85 – 96% of predicted adult height
3. Post-Puberty 96%+ of predicted adult height
Figure 1: Predicted height and percentage of adult height attained in Academy Footballers (Green bars = Post-PHV; Red bars = Circa-PHV; Blue bars = Pre-PHV)
The difficulty with working with youths going through PHV (90-91% of Predicted adult height) is there can be massive variances in biological age and usually timetabling issues make it hard to individualise each players’ needs. For example, you can have early developers that will go through PHV at a much earlier chronological age compared to late developers. Table 2 demonstrates a 2.5 year difference in biological age within a team of the same chronological age group.
Figure 2: Estimated years to and from PHV in Academy Footballers. (Green bars = Post-PHV; Red bars = Circa-PHV; Blue bars = Pre-PHV)
Typically, individuals that are post-PHV (green bars) are physically more robust and are capable of performing better physically. These individuals will tend to stand out in games as they have more ability to affect game play in a positive manner. The issue with this is they may become dependent on their physical prowess and focus less on technical ability as they aren’t physically challenged. The biologically younger players (blue bars) may ‘fly under the radar’ as they won’t stand out in games due to their smaller stature and will usually get beat easily by opponents. However, what we are starting to notice is the younger players that are demonstrating high levels of mental toughness/resilience long term, become greater players due to their tenacity to compete. Eventually these players will catch up biologically with the early developers and they will have a far greater technical and tactical mindset because they’ve had to learn to play the game differently. Hence why it is always important to pay attention to the needs of ‘the little guy’.
The players highlighted in red are currently going through PHV and are more at risk to growth related issues such as Osgood-Schlatter disease and Severs disease, as well as sporadic sensations of tightness and pain. This is simply due to the rapid change in growth. The bones grow rapidly, whilst the muscles don’t grow at the same rate, which in turn causes a sensation of tightness and may impact performance within a game. Loading patterns need to be very closely monitored in this stage and a great deal of focus should be on mobility to give the muscles as much support as possible to adapt to the new range of motion required to get through this stage with as little discomfort as possible. However, within the long-term development plan if there has been a good base of fundamental movement this should make this process easier to manage.
All program design should focus on good strong fundamental movement patterns such as Squat, Lunge, Hinge, Push, Pull, Brace and Rotate. Only when players are demonstrating solid technique should these movement patterns be loaded. Some players will excel and have natural abilities in strength, whilst others won’t be able to load up at all until certain points in their own development. Personally, I will add 5kg on to a squat once I feel their movement is smooth and watch how their body responds. If any movement is compromised such as: they sacrifice depth, show valgus (knocked knees) or there is lumbar flexion (curve their lower back) I will put them back to the only the bar. Typically, the majority of players will start getting stronger during PHV. Its difficult to pin point the exact point in maturation, as it is completely individual, however there will be that ‘light-switch’ moment where all of a sudden, they can start lifting loads that they couldn’t have before.
Alongside weightlifting, developing good explosive movement patterns is key to our LTAD plan. Pre-PHV the main focus is good jumping and landing mechanics. I will instruct the players to jump for height and distance whilst landing ‘like a ninja’ to ensure good safe movements. This will also cause an adaptation response in the nervous system, making it familiar to firing up motor units for explosive strength, so once players have gone through PHV there is maximum potential force going into the muscles. A key saying that has always stuck with me is “you are only as strong as the nervous system allows”. That being said, the more specific your training plan can be to the movement demands of the sport, the more force the nervous system will allow to maximise performance.
Post-PHV is an interesting time for any coach working with youth sports, as now the players will be able to perform physical feats that they may have struggled with before. Growth related issues should be less apparent and with those players you can start introducing plyometric drills and loading the weights up on the bars, which in turn will come with massive performance enhancement effects. This is at the point when your training plan should be fully periodised to allow maximum adaptation.
In conclusion, every athlete will go through PHV, but they will encounter this at a different time and a different rate. Due to this each athlete needs to be treated as an individual at this time, to allow the smoothest transition through this period. A well thought out LTAD plan will help aid this process and will ensure a decreased potential for injury and maximise performance outcomes. They key to this process is ensuring there is a strong fundamental base of good movement patterns throughout different planes of motion and ranges of motion. Following these simple steps will help create a strong robust athlete that is prepared for the higher demands of volume and intensity in the modern adult game.
NOTE: Thanks to Andy Bruce from the Youth Strength and Conditioning Coaches Facebook group, you can download a Microsoft Excel file of the Khamis-Roche monitoring calculator here: Khamis-Roche-Calculator-template . If you wish to read further on maturity monitoring and PHV this article on Biobanding in Sport is worth a read!