The 11-year-old who was told he had growing pains
An 11-year-old plays under-12s for his local AFL club. Six weeks into the season, he starts limping at training. The pain is behind the heel. It is worse on the harder ground at the new ovals, and worst in the morning after a Saturday game. His GP calls it growing pains and tells the family to rest him for two weeks. The family rests him for two weeks. He comes back. The pain comes back inside one training session. A second GP calls it Achilles tendinitis and prescribes anti-inflammatories. By the time he is referred for assessment, he has missed the back half of the season, his squat-test mechanics have deteriorated, and his mother is asking whether he should give footy away entirely.
This is calcaneal apophysitis. It is the single most common cause of paediatric heel pain in the Australian sporting age bracket (Wiegerinck et al., Eur J Pediatr 2014). It is, in 2026, neither obscure nor diagnostically difficult. And yet it remains routinely mismanaged at the primary-care interface — under-diagnosed early, over-restricted late, and rarely loaded thoughtfully through the middle.
This piece is a practice-orientated re-examination of the condition, with a particular interest in the part of the pathomechanism that is most clinically actionable: the triceps surae traction force that pulls on the apophysis from above.
Anatomy and pathomechanics — the apophysis as a secondary ossification centre
The posterior calcaneus develops as a separate secondary ossification centre that appears, by plain radiograph, between roughly seven and nine years of age and fuses to the calcaneal body somewhere between fourteen and seventeen (Volpon & de Carvalho Filho, J Pediatr Orthop 2002; Smith & Rao narrative review, J Clin Orthop Trauma 2024). Until fusion, the apophysis is mechanically a different beast to the surrounding bone. It is partially cartilaginous, lower in stiffness, lower in fatigue tolerance, and crossed by the calcaneal physis — a structure that under shear and tension behaves more like a growth plate than like bone.
The Achilles tendon inserts directly onto this apophysis. With every gait cycle, every run-up, every jump, the gastrocnemius–soleus complex transmits tension through the Achilles into the apophyseal attachment. In the skeletally mature foot, that tension is carried by the tendon and into mature, mineralised bone. In the eight-to-fourteen-year-old, it is carried into a secondary ossification centre that is structurally underbuilt for the load.
This is the apophysitis. Repetitive traction, delivered to a mechanically softer apophysis during the period of peak skeletal growth, produces microtrauma to the cartilage-bone interface and a clinical picture of activity-related posterior heel pain. The narrative reviews — Smith & Rao (2024), the Cureus conservative-management review of Smeed and colleagues (2025), and the older but still serviceable Hendrix consensus piece (Clin Podiatr Med Surg 2005) — converge on the traction-overload mechanism. There is no avascular necrosis. There is no inflammation in the rheumatic sense. There is mechanical overload of an immature attachment site.
Two adjuncts to the mechanism are worth holding in mind. First, the period of fastest longitudinal tibial growth runs ahead of the muscle-tendon unit’s ability to elongate, transiently increasing tension across the gastrocnemius–soleus–Achilles–apophysis chain (Micheli & Ireland, J Pediatr Orthop 1987; Belikan et al., J Orthop Surg Res 2022). Second, a sudden change in footwear — junior football boots with a near-zero heel drop, or a switch from runners to school shoes for the winter — can acutely increase the tensile demand on the apophysis by lengthening the working position of the calf-Achilles unit.
The framing that helps clinically is this: Sever’s and Achilles tendinopathy share a single pathway. Calf contraction generates Achilles tendon force. That force lands on whatever the weakest link is. In the adult tendon, the weak link is the midportion or the insertion. In the 10-year-old, the weak link is the apophysis, because the apophysis has not yet ossified into mature bone. Same traction force. Different failure site.
Epidemiology
In Wiegerinck’s Dutch general-practice cohort, calcaneal apophysitis presented at a rate of 3.7 per 1,000 registered patients aged 6–17 — making it more common in primary care than osteochondritis dissecans, Osgood-Schlatter, or any other paediatric osteochondrosis (Wiegerinck et al., Eur J Pediatr 2014). The median age at presentation was 12 in boys, 10 in girls. The condition is overwhelmingly an issue of the active child: in Belikan and colleagues’ retrospective ten-year audit of a German youth soccer academy, the incidence in academy players was 0.36 per 100 athletes per year, with bilateral presentations taking dramatically longer to resolve (209.5 days mean return to play, versus 45.9 days unilateral) (Belikan et al., J Orthop Surg Res 2022).
In the Australian junior-sport context, the at-risk populations are predictable: junior AFL and soccer (mixed-surface, high-volume running with a low-drop boot), basketball and netball (repeated jump-land cycles delivered at growth-plate-relevant frequencies), and gymnastics (high cumulative impact, often barefoot). The female peak runs a year or so earlier than the male peak, tracking skeletal maturation. Boys tend to present later and stay symptomatic longer, partly because boys hit their growth spurt later and partly because their training volumes ramp harder through the 12–14 bracket.
Differential diagnosis
The differential is not large but it is non-trivial. Posterior heel pain in the 8–14 age group is calcaneal apophysitis until proven otherwise. The conditions worth holding in the back of the mind:
Calcaneal stress reaction or stress fracture — uncommon in this age group but reported, particularly in cross-country runners and gymnasts with rapid training-load escalation. Tender directly over the calcaneal body, often with night pain or pain at rest. MRI clarifies.
Retrocalcaneal bursitis and Achilles insertional tendinopathy — more common in the late-adolescent who has already begun ossification of the apophysis. The pain is at the insertion or just anterior to the tendon in the retrocalcaneal recess, rather than at the medial-lateral squeeze test of the apophysis itself.
Tarsal coalition — typically presents with vague midfoot or hindfoot pain, recurrent ankle “sprains,” and a stiff subtalar joint on examination. CT or MRI confirms. Easy to miss if you don’t consider it.
Plantar fasciitis — rare in this age group and a flag to look harder. When it does occur, it is usually in the gymnast or the heavier child with marked pronation, and the pain is plantar-medial at the calcaneal tubercle, not posterior at the apophysis.
Osteomyelitis, tumour, juvenile idiopathic arthritis — uncommon, but the red-flag features (night pain unprovoked by activity, systemic symptoms, swelling beyond what the activity-load history explains, refusal to bear weight) earn imaging and bloods rather than reassurance.
A useful framing: if the medial-lateral compression squeeze of the calcaneal apophysis reproduces the pain — Sevigny’s sign, the bedrock test — and the history fits (active 8–14-year-old, post-activity heel pain, no rest pain, no systemic features), the diagnosis is clinical. Imaging is for atypical presentations, not for confirmation. Radiographs of the symptomatic apophysis are indistinguishable from the asymptomatic side (Better Health Channel, 2021; Smith & Rao, J Clin Orthop Trauma 2024).
What the trials actually show on management
The treatment literature on Sever’s is thin but converges on a consistent message. James, Williams and Haines’s 2013 systematic review (J Foot Ankle Res 2013) found nine eligible studies; effect sizes could not be pooled because the literature was too heterogeneous, but no single intervention emerged as clearly superior. Wiegerinck et al.’s 2016 pragmatic three-arm RCT (J Pediatr Orthop 2016) compared a wait-and-see protocol against a heel-raise inlay against supervised eccentric physiotherapy over ten weeks. All three arms improved. None was clearly better than the others. The Cureus comprehensive review of conservative management (Smeed et al., 2025) reaches the same conclusion: heel raises, custom orthoses, taping, calf flexibility work, load modification, and time all produce improvement; the evidence cannot meaningfully discriminate between them.
What this means in practice is not nihilism. It means the active ingredient is load management — not the specific delivery mechanism for offloading the apophysis. Anything that reduces the traction force per footfall during the symptomatic window will move the patient forward. The clinically interesting question is therefore which interventions reduce that traction force most efficiently and with least cost to the child’s sporting participation.
Load management without sport withdrawal
The most important shift in the modern management of Sever’s — and the one least well-translated to primary care — is that complete sporting rest is unnecessary and counterproductive. The Wiegerinck wait-and-see arm permitted ongoing participation modulated by symptoms; outcomes were no worse than the supervised-eccentric arm. The Belikan academy cohort kept players engaged through symptomatic management and saw unilateral resolution at a median 45 days.
A workable framework:
Reduce training volume to the level the child can tolerate without next-morning heel pain. Not zero. Not full. Find the calibration point and hold it there for two to four weeks before re-loading.
Heel raises in the shoe — six to nine millimetres — for the symptomatic period. The mechanism is straightforward: shortening the working position of the gastrocnemius–soleus–Achilles complex reduces the tensile demand on the apophysis at heel strike and during push-off (Bauerfeind ViscoHeel trial data; Wiegerinck et al., 2016).
Calf flexibility work, especially across the growth spurt window, where loss of dorsiflexion range correlates with symptom persistence.
Strength work for the triceps surae and the foot intrinsics, framed to the child and the parent as conditioning for sport rather than treatment for a disease. The pain-tolerance threshold here is the Silbernagel-style “up to 4/10 during, settled by next morning” — borrowed from the adult tendinopathy literature but appropriate for the same reason it works there.
Ice for symptomatic flare-ups; NSAIDs sparingly and only short-course. Cortisone is not appropriate at the apophysis and should not be considered.
The clinical importance of keeping the child in their sport — even at reduced volume — is not a soft argument. The Australian Institute of Sport’s position on early specialisation and the broader paediatric sports-medicine literature both flag complete withdrawal from sport during management of overuse injury as a major risk factor for permanent disengagement (ASC position statement; Jayanthi et al., Sports Health 2013). Three months out of a junior squad is not three months. It is, often, the end of a season and sometimes the end of a sport.
The soleus and Achilles angle
This is the part of the discussion that the Sever’s literature underweights. The driver of apophyseal traction is calf contraction. Inside the triceps surae, the soleus is the dominant generator of Achilles tendon force during walking and slow-to-moderate running — the muscle is roughly three times the physiological cross-sectional area of the medial gastrocnemius and predominantly slow-twitch (Ward et al., Clin Orthop Relat Res 2009). For the 11-year-old running through training and competition, the soleus is delivering most of the cyclic Achilles load that reaches the apophysis.
Two clinical implications follow.
First, calf-conditioning work for the symptomatic child should not skip the knee-flexed bent-knee calf raise — the position that biases the soleus when the biarticular gastrocnemius is taken off active length. The standard straight-leg heel raise is necessary but insufficient if the soleus is left unaddressed.
Second, anything that reduces the per-footfall calf activation profile during sport — particularly the standing and slow-running portions where the soleus dominates — is a candidate mechanism for symptom modulation. This is the rationale behind external load-modifying interventions during the symptomatic window.
The Orthopaedic Sleeve as adjunct: addressing the ambulatory traction dose
The Wiegerinck framework is, in essence, an instruction to modify load without eliminating it. Heel raises shorten the working length of the gastrocnemius–soleus–Achilles unit. Training-volume reduction lowers the peak per-session traction dose. Calf conditioning raises the tolerance of the chain. What the framework leaves under-addressed is the load the apophysis takes between sessions — the walk to school, the standing and weight-shifting at recess, the kick-around in the backyard. Each is a heel-traction event. For the symptomatic child in the keep-them-playing pathway, the cumulative ambulatory dose across a week is non-trivial, and it sits below the threshold at which most clinical management currently intervenes.
The Orthopaedic Sleeve is the adjunct that addresses that gap. It is a lower-limb sleeve developed for adult Achilles tendinopathy, and the mechanism — a reduction in triceps surae activation and the consequent attenuation of Achilles tendon force during gait — is mechanistically congruent with the offloading objective in apophysitis. The University of Queensland Final Report (June 2025) documents three findings worth holding distinct.
First, the headline biomechanical finding: an 8.1% reduction in peak Achilles tendon force during walking, derived via Hill-model analysis on the best-responding individuals. This is the number that matters for Sever’s. The Achilles is the traction effector at the apophysis; an 8.1% reduction in peak tensile force is, mechanically, an 8.1% reduction in the per-step dose delivered to the secondary ossification centre.
Second, the EMG finding from quiet standing balance: a 32% reduction in medial gastrocnemius activation. This is a group-significant finding and reflects the postural-control task, not the gait task. It is the clearest demonstration that the device reduces calf-muscle drive in low-demand standing conditions — a population-level effect in a task that is not the apophyseal-load task. Worth citing for mechanism. Do not conflate it with the per-step apophyseal dose.
Third, the individual-maximum findings from the late-stance walking phase: peak reductions in lateral gastrocnemius (47.8%), medial gastrocnemius (21.9%), and soleus (20.4%) activation in the best-responding individual on the propulsive substroke of gait. These are individual maxima, not group means. They sit above the group-significant standing-balance finding and indicate that for some children — particularly those whose symptomatic walking gait recruits the triceps surae heavily — the per-step calf-activation reduction can be larger than the standing-task finding suggests. Position the individual maxima as the upper bound of effect; the 8.1% Achilles tendon force figure as the realistic per-step expectation.
For the paediatric clinical translation: this is the adjunct for the patient on the keep-them-playing pathway whose ambulatory background load is sustaining the symptoms between sessions. The Sleeve does not replace the heel raise, the volume modification, or the calf-conditioning programme. It augments them by addressing the load category the others do not — the cumulative ambulatory dose during waking hours that the apophysis takes whether or not the child trains that day.
Framed honestly: the device is primarily designed for, and trial-evidenced in, the adult tendinopathic population. The pathway is identical — calf contraction generates Achilles tension which lands at whatever the weak link happens to be, the midportion of a 35-year-old tendon or the apophysis of an 11-year-old — but the paediatric trial evidence is yet to be generated. Sizing for younger or smaller limbs should be verified before fitting. The device does not change the natural history of apophysitis; the apophysis closes when it closes. What it offers is an attenuation of the per-step traction dose during the symptomatic window, with the goal of shortening that window and protecting the child’s continued sporting participation through it.
This is the clinical edge for the paediatric patient who is being kept in sport at modified volume: a load-modification tool that works between sessions, at source, with every step.
Three clinical translations
Three patterns repay attention.
The active 10–12-year-old with three weeks of post-training posterior heel pain, no rest pain, positive medial-lateral squeeze of the apophysis: clinical diagnosis, no imaging, training-volume reduction calibrated to next-morning symptom return, heel raises in sport shoes, calf conditioning with bent-knee work, and a planned re-loading window over six to eight weeks. Most resolve.
The 13-year-old with bilateral symptoms across two consecutive seasons, persistent dorsiflexion restriction, and a history of cortisone or extended rest from a prior clinician: longer horizon. Expect three to six months of management, including formal calf-conditioning programming, footwear review, and explicit conversation with the family about staying in sport at modified volume rather than withdrawing.
The atypical case — night pain, swelling, refusal to weight-bear, fever, recent sprain, or symptoms that do not match the apophysitis-squeeze pattern: image, exclude the differentials, and refer if any of the red flags hold up.
In all three, the family-facing message should be the same: Sever’s is self-limiting at skeletal maturity. The job between now and then is to keep the child playing, manage the traction force on the heel, and avoid the well-documented harm of pulling them out of their sport for longer than the pathology requires.
References
Belikan P, Färber LC, Abel F, et al. Incidence of calcaneal apophysitis (Sever’s disease) and return-to-play in adolescent athletes of a German youth soccer academy: a retrospective study of 10 years. J Orthop Surg Res. 2022;17:83.
Better Health Channel (Victoria Department of Health, Australian Physiotherapy Association). Sever’s disease. Updated 2021.
Hendrix CL. Calcaneal apophysitis (Sever disease). Clin Podiatr Med Surg. 2005;22(1):55–62.
James AM, Williams CM, Haines TP. Effectiveness of interventions in reducing pain and maintaining physical activity in children and adolescents with calcaneal apophysitis (Sever’s disease): a systematic review. J Foot Ankle Res. 2013;6:16.
Micheli LJ, Ireland ML. Prevention and management of calcaneal apophysitis in children: an overuse syndrome. J Pediatr Orthop. 1987;7(1):34–38.
Smeed J, et al. Conservative Management of Sever’s Disease (Calcaneal Apophysitis): A Comprehensive Review of Treatment Efficacy. Cureus. 2025.
Smith JM, Rao S. Heel pain in young athletes — not always Sever’s Disease: A Narrative Review. J Clin Orthop Trauma. 2024.
Volpon JB, de Carvalho Filho G. Calcaneal apophysitis: a quantitative radiographic evaluation of the secondary ossification centre. Arch Orthop Trauma Surg. 2002;122(6):338–341.
Ward SR, Eng CM, Smallwood LH, Lieber RL. Are current measurements of lower extremity muscle architecture accurate? Clin Orthop Relat Res. 2009;467(4):1074–1082.
Wiegerinck JI, Yntema C, Brouwer HJ, Struijs PA. Incidence of calcaneal apophysitis in the general population. Eur J Pediatr. 2014;173(5):677–679.
Wiegerinck JI, Zwiers R, Sierevelt IN, et al. Treatment of calcaneal apophysitis: wait and see versus orthotic device versus physical therapy — a pragmatic therapeutic randomized clinical trial. J Pediatr Orthop. 2016;36(2):152–157.
University of Queensland, School of Mechanical and Mining Engineering. The Orthopaedic Sleeve: Biomechanical Assessment — Final Report. June 2025.