Depth Jumps for a Twelve-Year-Old With Heel Pain
Owen is 12 years old (158 cm, 47 kg) and plays competitive basketball four times a week plus physical education. His mother reports that he has grown 6 cm in the past year and that his shoe size changed twice. For three weeks he has had pain at the back of both heels, worse after practice, better with rest, and he limps slightly in the morning. There is tenderness when the heel is squeezed from the sides, no swelling, and no history of a single injury. He wants to add a plyometric block to improve his vertical jump; his skills coach has prescribed three sessions per week of 5 × 8 depth jumps from a 45 cm box onto a wooden floor, plus 100 rope skips. On video, Owen lands heel-first with his knees collapsing inward.
1. What is the most likely source of heel pain, and how does his growth history explain it? When would you refer?
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Likely diagnosis Calcaneal apophysitis (Sever's disease): traction apophysitis at the Achilles insertion on the calcaneus. The presentation fits - bilateral posterior heel pain, worse with activity and better with rest, morning limp, tenderness on lateral squeeze, no swelling, no acute injury, and a recent growth spurt.
Why growth matters During a rapid growth spurt, long bones lengthen faster than the muscle-tendon unit can accommodate. The calf complex becomes relatively tight, increasing pulling force at the apophysis, which is cartilage and mechanically weaker than mature bone. Add four basketball sessions, physical education, jumping, and hard indoor surfaces, and the load exceeds the tissue's tolerance.
Referral thresholds Refer to a physician or physiotherapist if there is: pain at rest or at night, visible swelling or warmth, inability to bear weight, focal tenderness away from the apophysis, fever, or no meaningful improvement after 2–4 weeks of load management. Also refer if pain is consistently above 4/10 or prevents participation. Otherwise, this is managed with load modification, not imaging.
2. Critique the coach's plyometric prescription and rewrite it for the next six weeks with numbers.
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Critique
- 45 cm depth jumps are a high-intensity exercise requiring excellent landing mechanics and a base of strength; Owen is a beginner who lands heel-first with knee valgus.
- Three sessions per week is too frequent for high-intensity plyometrics. Depth jumps should generally be limited to once or twice weekly with 48–72 hours between.
- Volume is excessive: 5 × 8 = 40 depth jumps per session, 120 per week, plus 100 skips - roughly 220 contacts, far beyond a beginner's tolerance.
- A wooden floor with heel-first landings adds impact stress during an active apophysitis.
Six-week rewrite Weeks 1–2: two sessions per week, 30–40 foot contacts total of low-intensity work - pogo hops, snap-downs from a 15 cm box, lateral hops - on a sport court or grass, in supportive shoes. No depth jumps. Weeks 3–4: 50–60 contacts; introduce 20–25 cm box snap-downs and low hurdle hops. Continue two sessions per week. Weeks 5–6: 60–80 contacts; add 30 cm depth jumps only if landings are quiet and pain-free. Keep basketball load reduced during weeks 1–2.
Rule: stop the set when landing quality degrades; pain must stay at or below 2/10 during and 24 hours after.
3. What landing mechanics and monitoring would you teach, and how do you decide when to progress?
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Landing cues
- 'Quiet landings' - aim for minimal sound on contact.
- Land on the mid-foot/forefoot, not the heel, with the ankle, knee, and hip stacked.
- Hips back, chest up, knees tracking over the second toe; hold the landing for 3 seconds before the next rep.
- Use video feedback once per session; children this age respond well to seeing one clear frame.
Supporting work
- Calf raises (straight and bent knee), hip abductor work, and hamstring bridging to build the strength that absorbs landing force.
- Daily calf stretching at the wall, plus heel cups or cushioned insoles as an adjunct.
Monitoring
- Pain score before, during, and 24 hours after each session, recorded on a simple 0–10 card.
- Morning stiffness and limp checked daily by a parent.
Progression criteria Progress only when: 24-hour pain is 0–2/10, morning limp has resolved, and 10 consecutive quiet landings with knees aligned are achieved. Advance one variable at a time - volume first, then box height (15 → 25 → 30 cm), never both at once. Coordinate with the basketball coach so total jumping load, not just the plyometric block, is managed.