Research · Injury & Recovery

A Teenager's Back Pain Is Not an Adult's Back Pain

By Muhammad Dzulhisham · MSc Sports Coaching, NSCA-CSCS

A fifteen-year-old says their lower back hurts. It is worse arching backwards, worse after training, better with a few days off. The reflex response is the one we apply to adults: probably muscular, give it a week, keep moving.

That reflex is calibrated to the wrong population. In adults, roughly 5% of back pain is attributable to a pars stress fracture. In young athletes presenting with low back pain, a single-arm meta-analysis of nine studies covering 835 patients put the figure at 41.7% (95% CI 0.28–0.55).¹ Same complaint, an order of magnitude apart in what is likely causing it.

How common is the pain in the first place

Common enough that it should not be treated as a red flag on its own. A systematic review and meta-analysis of 80 studies examined low back pain in adolescent athletes across all sports.²

The risk factors the review identified were sport participation itself, sport volume and intensity, concurrent lower-extremity pain, overweight or high BMI, older adolescent age, female sex and family history of low back pain.² The most commonly reported underlying morphology across the literature was spondylolysis.

Note the honest framing the authors put on their own numbers: prevalence and incidence varied considerably because of differences in study methodology, in how low back pain was defined, and in how data were collected. Quality was rated high in 73% of cross-sectional studies but only 30% of cohort studies, with downgrades commonly for using non-validated survey instruments or failing to define low back pain at all.²

What spondylolysis actually is

It is a stress fracture of the pars interarticularis — a thin bridge of bone in the vertebral arch. The current-concepts picture is a progression rather than an event: a stress reaction in the pars, then an incomplete stress fracture, then a complete one.³ It occurs most often at L5, then L4, and is bilateral in around 80% of symptomatic cases; unilateral defects run a more benign course. The loading pattern that drives it is repetitive hyperextension, which is why it clusters in sports involving trunk extension and rotation.³

A Japanese single-institution series of 197 male and 64 female adolescents adds useful texture on who presents and with what.⁴ Males had more spina bifida occulta (p=0.0026), more lesions showing bone marrow oedema (p=0.0097), and more L5 lesions (p=0.021). The sports differed by sex — baseball, soccer and track and field in males; volleyball, basketball and softball in females. What did not differ was arguably more useful: dropout rate, age at diagnosis, bone union rate and treatment duration were the same in both.⁴ The lesion presents differently but behaves similarly.

The treatment finding that should reset expectations

The largest published series reviewed 201 adolescent athletes aged 10 to 19 treated between 2007 and 2019, all managed conservatively: cessation of sport, a thoracolumbosacral brace and an external bone stimulator for three months, followed by six weeks of core-focused rehabilitation.⁵

Put the first two tiles next to each other. Ninety-eight per cent went back to sport; barely half the fractures had healed on imaging. Whatever conservative management is achieving in this condition, it is not primarily bone union — and the athletes who returned with an unhealed pars defect were, for the most part, not thereby prevented from playing.

That finding cuts both ways and should be read carefully. It argues against treating a follow-up scan as the permission slip for return to sport. It also means a substantial number of young athletes are carrying an ununited defect into adulthood, and this series followed them only to return-to-play, not for years afterwards.

Two other details from the same cohort are directly actionable for a strength coach. The primary injury mechanism was weight training, closely followed by football; the most commonly played sport was football, then baseball and softball.⁵ And injuries clustered in the first quarter of the calendar year, peaking in March — a preseason signal, not a competition-season one.

How long it takes

This is where parents need a real number rather than reassurance. A case-control study of 82 young athletes with early-stage lumbar spondylolysis, mean age 14.8, compared standard conservative treatment — brace, sports modification, therapeutic exercise — with or without low-intensity pulsed ultrasound.⁶

The standard-care figure is the one to carry into the conversation: a median of roughly five and a half months, with an upper confidence bound approaching nine. That is a season, not a lay-off.

The ultrasound result is striking and deserves its caveat stated clearly. Patients were allocated by sequence of admission rather than randomised, the sample was 80 boys and 2 girls, and it was conducted at a single clinic. A near three-fold difference in return time is a hypothesis worth testing properly, not a settled treatment.

What this changes in practice

Invert the default assumption. In an adolescent athlete, low back pain that is worse in extension is a suspected pars stress fracture until a clinician says otherwise — not a muscle strain until proven otherwise. The base rates justify the reversal.

Look at the gym, not just the sport. Weight training was the leading mechanism in the largest series. Loaded extension under fatigue is the pattern to coach out, and preseason is when it happens — another reason what a teenager should be lifting is a coaching question before it is a numbers question.

Give a season-length timeline from day one. Median return was about 167 days under standard care. Promising weeks sets up a mid-recovery argument you will lose.

Do not wait for the scan to look perfect. Half these athletes returned without radiographic union. Symptoms and function drive return; the current-concepts position is simply that athletes should not return until pain free.³

Treat back pain in a young athlete as a load question. Sport volume and intensity were among the identified risk factors, alongside factors nobody can change like sex, age and family history. The volume is the part you control.

Where this evidence stops

The prevalence figures come with wide confidence intervals and considerable heterogeneity, driven by a literature that has not agreed how to define or measure low back pain in this population. The 41.7% spondylolysis figure is drawn from athletes who presented for care and were imaged, which is a selected group — it is not the rate among all young athletes with a sore back, and it should not be read as such.

The treatment evidence is worse. The 201-case series is retrospective with no control arm, so the 98% return rate cannot be attributed to the brace, the bone stimulator, the rehabilitation or simply to time. The ultrasound study was not randomised. There is no large-scale trial establishing an optimal protocol, and the current-concepts review says so directly.

Finally, the obvious: this is a fracture. Diagnosis and management belong with a clinician, and imaging decisions in a growing spine involve radiation-exposure trade-offs that are not a coach's call. What the evidence supports here is narrow but worth acting on — take adolescent back pain more seriously than adult back pain, look hard at loaded extension in the weight room, and plan for months.