Why young footballers, rugby kickers and sprinters need to respect their growing bones
By Mr Nev Davies, Consultant Children’s Orthopaedic Surgeon
I was watching one of my boys practising his rugby kicking on holiday in Lanzarote recently. Ball on the tee, a few steps back, run-up, kick. Retrieve the ball and repeat.
Like thousands of children across the country, he loves his sport and wants to improve.
As a dad, I love seeing that enthusiasm. As a children’s orthopaedic surgeon, however, I know there is something important going on beneath the surface.
A teenager’s muscles are getting stronger, their technique is improving and they can generate some extraordinary forces through their hips and pelvis. But their growing skeleton is not quite the same as an adult’s.
And occasionally, when a young athlete sprints explosively or strikes a ball with maximum force, something gives way.
Surprisingly, it isn’t always the muscle or tendon.
Sometimes the tendon is stronger than the bone it is attached to.
The result can be a pelvic avulsion fracture, an injury that can keep a talented young athlete out of sport for months.
The good news is that we can reduce many of the risk factors, and it starts with understanding how a teenager’s pelvis grows.
Why are growing teenagers particularly vulnerable?
Children have growth plates, areas of developing cartilage that allow their bones to grow.
Most parents have heard of the growth plates at the ends of the long bones, but there are also specialised growth centres where powerful muscles and tendons attach to the pelvis.
These are called apophyses.
In an adult, the tendon attaches to mature bone. In a growing teenager, that attachment may still involve a relatively vulnerable area of developing cartilage.
Think of it as a very strong rope attached to a point that is still under construction.
The rope can generate enormous pulling forces, but the attachment is not yet fully mature.
This becomes particularly important during adolescence, especially around a rapid growth spurt. Bones may lengthen faster than muscles adapt, leaving young athletes feeling tight, stiff or less flexible than they were a few months earlier.
Combine that with powerful muscle contractions, repetitive sporting activity and inadequate recovery, and you have the ingredients for an injury.
The two injuries every parent and coach should recognise
There are two main ways these injuries develop, and understanding the difference is important.
1. Pelvic apophysitis, the warning sign that can build gradually
Apophysitis is irritation of a growing tendon attachment caused by repetitive loading.
In a young footballer or rugby kicker, that might mean hundreds of kicks across several sessions, with insufficient time for recovery.
Initially, the teenager might complain of a vague ache around the front of the hip, groin or buttock.
It may only hurt after training. Then it starts hurting during training, perhaps when sprinting or kicking particularly hard.
Often, they can continue playing.
And therein lies the problem.
Because the discomfort settles with rest, young athletes can convince themselves that nothing is wrong. They return to training, repeat the same activity and irritate the attachment again.
It is a little like Osgood-Schlatter condition at the knee or Sever’s condition at the heel, both of which I see regularly in growing children.
The mechanism is similar, repetitive pulling on a developing area of bone.
Most cases settle with appropriate activity modification and rehabilitation. However, continuing to overload a painful apophysis can prolong recovery and may contribute to the risk of an avulsion injury.
2. Pelvic avulsion fractures, when the injury happens suddenly
This is a different situation.
Imagine a 15-year-old rugby player attempting a long conversion. He takes his run-up and strikes the ball with maximum force.
Suddenly, he feels an intense stabbing pain at the front of his hip.
He might hear or feel a pop.
He cannot continue kicking and may struggle to walk normally.
The powerful contraction of the muscle has pulled away part of its bony attachment.
That is an avulsion fracture.
It is a genuine fracture, even though there has been no collision, fall or direct blow.
These injuries can happen to extremely fit, talented teenagers, particularly during explosive movements such as sprinting, kicking, jumping and rapid acceleration.
The rectus femoris avulsion, a particular risk for young kickers
One of the classic injuries occurs at a small bony prominence at the front of the pelvis called the anterior inferior iliac spine, or AIIS.
This is where the direct head of the rectus femoris muscle originates.
The rectus femoris is unusual because it crosses both the hip and knee joints. It helps lift the thigh forwards and straighten the knee.
Both actions are involved in kicking a football or rugby ball.
During a powerful kick, the muscle-tendon unit is exposed to considerable force, particularly as it rapidly lengthens and contracts through the kicking movement.
In an adolescent, the vulnerable attachment at the pelvis can fail, pulling away a small fragment of bone.
The typical symptoms include sudden pain at the front of the hip or groin, tenderness over the bony attachment and difficulty kicking, sprinting or lifting the leg against resistance.
These injuries are sometimes initially mistaken for a hip flexor strain.
That distinction matters because an avulsion fracture requires a different assessment and a more cautious return to sport.
The dreaded hamstring avulsion, every sprinter’s nightmare
Now move around to the back of the pelvis.
The hamstring muscles originate from the ischial tuberosity, the prominent bone beneath your buttock that you sit on.
In adults, a powerful sprint can cause a hamstring muscle injury or occasionally a tendon rupture.
In teenagers, the growth centre at the ischial tuberosity may be the weakest link.
A sudden acceleration, maximal sprint or forceful hamstring contraction can pull the apophysis away from the pelvis.
The athlete may experience an immediate, sharp pain deep in the buttock or upper hamstring.
Sometimes there is an audible pop. Sitting becomes painful, walking may be difficult and bruising can develop down the back of the thigh.
This is an injury that deserves particular respect.
Although many hamstring origin avulsion fractures heal without surgery, a significantly displaced fragment, persistent weakness or ongoing pain may require specialist surgical assessment.
It is especially important not to dismiss a sudden severe upper hamstring injury in a teenager as a simple pulled muscle.
1. Start position. 2. Explosive push-off. 3. Acceleration. 4. Sprint away. Sprinting demands rapid, powerful contractions around the hip and pelvis. In a growing athlete, the pelvic apophyses may be vulnerable to sudden traction forces. The photographs illustrate the movement, not recommended footwear.
Is stretching before kicking the answer?
Stretching is useful, but this is where I would challenge a common assumption.
We have all seen a group of children arrive at training, stand around for a few minutes, perhaps pull their heel towards their bottom, and then immediately start sprinting or kicking at maximum intensity.
That is not really a warm-up.
Before explosive sporting activity, I prefer a progressive dynamic warm-up.
Rather than simply holding muscles in a stretched position, dynamic exercises take the muscles and joints through controlled movements, gradually increasing their range, speed and intensity.
For a young footballer or rugby kicker, a sensible warm-up might include:
Two minutes of easy jogging and movement.
Controlled walking lunges, leg swings and hip mobility exercises.
Side stepping, skipping and gentle changes of direction.
Progressive accelerations, increasing speed over several repetitions.
Short, easy kicks, gradually progressing towards normal kicking distance and intensity.
The whole process might take around 10 to 15 minutes.
The precise routine is less important than the principle.
Do not go from standing still to maximum effort in one movement.
What about traditional static stretching?
Gentle static stretching can help develop flexibility and can be useful within a wider conditioning programme. But stretching alone has not been shown to prevent pelvic avulsion fractures.
Prolonged static stretching immediately before explosive activity is also not necessarily the best way to prepare muscles for powerful movement.
My preference is controlled dynamic mobility before sport, with additional flexibility work when appropriate, alongside strengthening and good load management.
And one particularly important warning: if a teenager already has pain around a pelvic growth centre, do not try to stretch it away aggressively.
That can increase traction on an already irritated or injured attachment.
A gentle half-kneeling stretch can help flexibility. It is not a substitute for a dynamic warm-up or sensible workload, and painful stretching should be avoided.
How much kicking is too much?
This is probably the question I am asked most often by parents of ambitious young athletes.
And the answer is frustratingly difficult.
There is no scientifically established maximum number of kicks that is safe for every teenager.
A 13-year-old who has been practising kicking twice a week for several years may tolerate a very different workload from another child who has recently started.
Growth, physical maturity, strength, technique, previous injuries, fatigue and recovery all make a difference.
Importantly, ten gentle kicks are not the same as ten maximum-distance kicks.
The intensity of each repetition matters, not simply the number.
The problem with playing for several teams
Imagine a talented 14-year-old who plays rugby for school and club and attends a representative development programme.
At school, he practises kicking.
At club training, he practises kicking.
At his development programme, he practises kicking.
Then, on Sunday, he spends half an hour on the pitch attempting long conversions before the match.
Each coach may feel the workload is entirely reasonable.
But nobody has necessarily added it all together.
This is a familiar problem across youth sport. The individual sessions may be sensible, but the combined load becomes excessive.
I see similar situations with young cricketers bowling for several teams, footballers playing multiple fixtures and runners training across school and club programmes.
Five practical rules for managing training load
1. Keep track of the total load. Parents and coaches should consider all sporting activity across school, clubs, academies and individual practice, not just their own training sessions.
2. Build up gradually. Sudden increases in kicking volume, sprinting or high-intensity training are more concerning than workloads that have increased progressively over time. There is no universally safe weekly percentage increase.
3. Protect recovery time. The American Academy of Pediatrics advises young athletes to have at least one to two days each week away from competition and sport-specific training, with meaningful breaks from individual sports across the year.
4. Take growth spurts seriously. A teenager who has suddenly grown several centimetres, feels unusually tight or complains of recurring hip discomfort may need a temporary reduction in training intensity.
5. Never encourage children to push through worsening pain. Pain that returns with each session or is still present the following morning deserves attention.
We want young athletes to train and improve. We simply need to give their developing bodies enough time to adapt.
The traffic light guide for parents and coaches
I think a simple traffic light system can be particularly helpful.
GREEN: Keep going
Your child is pain-free during sport, moves normally afterwards and recovers without persistent discomfort.
Training can continue, with sensible progression and adequate rest.
AMBER: Reduce the load
Your child develops recurring hip, groin or buttock pain with kicking or sprinting. Their technique changes, they feel increasingly stiff or the discomfort persists into the following day.
Reduce or stop the provoking activity and arrange assessment if symptoms persist or recur.
Do not simply cover up the pain with medication and send them back onto the pitch.
RED: Stop and get checked
Your child experiences sudden severe pain, perhaps with a pop, while kicking, sprinting or jumping.
They cannot continue, are limping significantly or struggle to bear weight.
Stop the session and arrange prompt medical assessment, particularly if an avulsion fracture is suspected.
Do not stretch the area forcefully or attempt another kick to see whether it has settled.
How do I diagnose a pelvic avulsion injury?
The first step is listening carefully to the history.
A sudden injury during one explosive movement, especially with a pop and immediate loss of function, raises concern for an avulsion fracture.
Gradually increasing pain during repeated sporting activity is more suggestive of apophysitis.
Examination helps identify exactly which muscle attachment is painful.
If I suspect an avulsion fracture, I will usually arrange an X-ray of the pelvis.
This may clearly demonstrate a small fragment of bone that has been pulled away from its normal position.
Occasionally, particularly when the growth centre is still largely cartilage, the injury may not show clearly on an X-ray.
In those circumstances, or when the diagnosis remains uncertain, an MRI can be very helpful.
It is also important not to assume that all hip and groin pain in teenagers is an overuse injury. Other conditions, including a slipped upper femoral epiphysis (SUFE), must sometimes be excluded.
Will my child need surgery?
Thankfully, most pelvic apophyseal injuries do not require an operation.
For apophysitis, treatment usually involves reducing the aggravating activity, addressing strength and flexibility deficits, and gradually rebuilding the athlete’s tolerance to sport.
For an avulsion fracture, there is usually a period of rest and protected movement, sometimes with crutches, followed by progressive rehabilitation.
Many teenagers recover well without surgical treatment.
However, a significantly displaced fragment, persistent symptoms, functional problems or certain high-demand sporting circumstances may lead us to consider surgery.
The decision depends on the site of injury, the amount of displacement, symptoms and the individual athlete.
There is no single displacement measurement that automatically means every child requires an operation.
How long before they can play again?
This is where patience becomes important.
Mild apophysitis may settle over several weeks, although some children experience recurring symptoms over a longer period.
An uncomplicated avulsion fracture often requires several months of rehabilitation before unrestricted sport, with recovery varying according to the attachment injured and the severity of the fracture.
More significant hamstring origin injuries can require longer.
The important thing is not to return simply because a certain number of weeks have passed.
I want to see a young athlete walking normally, regaining strength and movement, and completing progressively demanding sport-specific activities without pain or a reaction afterwards.
For a rugby kicker, that means progressing from gentle ball striking to normal kicking distances and eventually maximum-effort kicks.
For a sprinter, it means restoring acceleration, speed and high-intensity running in stages.
A rushed return risks a recurrence or a prolonged recovery.
My advice to parents, coaches and talented young athletes
I am enormously enthusiastic about children’s sport.
I am a rugby coach, a dad to three sporty boys and a children’s orthopaedic surgeon. I love seeing young athletes improve, compete and push themselves.
But I also see the other side, talented teenagers sitting in clinic, understandably devastated because an injury has interrupted their season.
We cannot prevent every sports injury.
What we can do is recognise that a growing skeleton has different vulnerabilities from an adult one.
We can take warm-ups seriously, develop strength and control, avoid sudden increases in kicking or sprinting loads, and make sure children get adequate recovery.
And perhaps most importantly, we can listen when they tell us something hurts.
A young athlete who complains of recurring pain around the hip or pelvis is not necessarily being soft or lacking commitment.
Their body may simply be telling us that the load is exceeding its current capacity.
Sometimes the best way to help a young athlete become stronger is to ask them to do a little less today, so they can do much more tomorrow.
And sometimes, the smartest coaching decision is to say:
“That’s enough kicking for today.”
Frequently asked questions
Can a teenager fracture their pelvis just by kicking a ball?
Yes. A powerful muscle contraction can pull a small fragment of bone away from a developing tendon attachment. This is called a pelvic avulsion fracture.
Is groin pain after football or rugby always a muscle strain?
No. It may be a muscle strain, but pelvic apophysitis and avulsion fractures are important possibilities in growing teenagers. Persistent pain or sudden severe symptoms should be assessed.
Does stretching prevent pelvic avulsion fractures?
Not reliably. Appropriate flexibility is useful, but a progressive warm-up, strength and conditioning, gradual loading and adequate recovery are all important. No routine can eliminate the risk completely.
What age are children most at risk?
These injuries are particularly relevant during adolescence, when pelvic apophyses have not fully fused. The exact ages vary with individual growth and skeletal maturity.
Should my child stop playing sport if they have pelvic apophysitis?
They should stop or reduce painful activities initially, particularly repetitive kicking or sprinting. They may be able to maintain fitness through comfortable alternative activities while following an appropriate rehabilitation plan.
Ask Debbie about a consultation
Written by Mr Nev Davies FRCS (Tr.&Orth.)
Consultant Trauma & Orthopaedic Surgeon, specialising in children’s orthopaedics and knee surgery.
This article provides general information and is not a substitute for individual medical assessment. If your child develops sudden severe hip or pelvic pain, cannot bear weight, has a persistent limp, or is unwell with fever, seek prompt medical advice.
More for parents of young athletes
You may also find these guides helpful: Why does my child have knee pain after sport?, Sever’s condition (children’s heel pain), My child is limping: when to worry, Weight training for teenagers: is it safe? and Sleep: the most underrated performance tool for young athletes. You can find all of Nev’s articles on the blog.
Sources and further reading
Royal Children’s Hospital Melbourne, Pelvic Avulsion Injuries, Emergency Department
Schuett et al and related review, Treatment of Avulsion Fractures of the Pelvis in Adolescent Athletes
American Academy of Pediatrics, Overuse Injuries, Overtraining and Burnout in Young Athletes, Pediatrics 2024
