Active lumbar spondylolysis in adolescent athletes: physiotherapy immediately or rest first? (commentary on a randomized trial)

Today we analyze this article

Selhorst and colleagues published a multicenter randomized trial in the British Journal of Sports Medicine that addresses a daily question: in "active" lumbar spondylolysis in adolescent athletes, is it better to start physical therapy immediately or wait for a period of rest until symptoms resolve before starting rehabilitation?

Reference: Selhorst M, et al. Br J Sports Med. 2025. PMID: 41402030. Trial: NCT05505981.

Why the issue is important

In adolescent athletes, spondylolysis is often described as a bone stress injury of the pars interarticularis, and the literature has historically focused on diagnosis, radiographic healing, the role of bracing, and rest. The timing of rehabilitation, however, has been less "tested" with robust experimental studies.

What they did (brief design)

• Participants: 64 adolescent athletes (10–19 years old) with "active" lumbar spondylolysis.
• Comparison:
  1. Immediate physical therapy, started within 7 days of diagnosis, with progression guided by pain and function.
  2. Rest before physical therapy, with physical therapy initiated after symptom resolution and time-based progression.
• Primary outcome: Micheli Functional Scale at 1 month (then 3 and 12 months).
• Secondary outcomes: time to return to sport and recurrence of back pain at 12 months.

Results (the ones that matter)

• At 1 month: greater functional and pain improvement with immediate physical therapy → mean difference 21.3 points (95% confidence interval 28.7–13.9; p<0.001).
• Return to sport: faster with immediate physical therapy → approximately 38 days earlier (p<0.001).
• Recurrences at 12 months: much less frequent with immediate physical therapy → 3% versus 29% (p=0.01).
• Adverse events: not reported.

Practical interpretation

The point is not "no rest," but no passive waiting. The study suggests that, when the diagnosis is clear and there are no red flags, it may be more useful to:

• temporarily reduce provocative movements,
• start a structured rehabilitation program early,
• progressively reintroduce even "sensitive" movements (extension/rotation) because, like it or not, they are functional movements in many sports and need to be rebuilt carefully.

The most convincing data is the reduction in recurrences: it's not just a faster return, but potentially a more "stable" return.

Limitations to remember

• Not a huge sample (64), although with clear effects.
• Specific population: adolescent athletes (transferability to other profiles needs to be evaluated).
• Some technical details require reading the full text, beyond the abstract.

In summary

For "active" lumbar spondylolysis in adolescent athletes, this trial shifts the needle towards more active management: early and progressive physical therapy (with intelligent load management) instead of waiting for complete symptom disappearance before starting rehabilitation.

Disclaimer: informational content, does not replace individual clinical evaluation.

Essential Bibliography

1. Selhorst M, et al. Immediate physical therapy is beneficial for adolescent athletes with active lumbar spondylolysis: a multicentre randomised trial. Br J Sports Med. 2025. PMID: 41402030.
2. Selhorst M, et al. Rehabilitation Considerations for Spondylolysis in the Youth Athlete. Int J Sports Phys Ther. 2020. PMID: 32269862. (PMCID available)
3. Overley SC, et al. Return to Play in Adolescent Athletes With Symptomatic Spondylolysis Without Listhesis: A Meta-Analysis. Global Spine J. 2018. PMID: 29662750. (PMCID available)