Spondylolysis: Low Back Pain in Young Hockey and Gymnastics Athletes

A 14-year-old goalie has had a sore low back for six weeks. It's worse after practice, especially when she arches back to track a high shot, and better with a few days off. Everyone has assumed it's a muscle strain. It hasn't gone away.

This is a common story, and in a young athlete it deserves a different level of attention than it would in an adult. Adolescent spines are still growing, and the pattern of injuries they get is different. One of the most common causes of persistent low back pain in young athletes is a condition called spondylolysis, and it's often missed for weeks or months because it gets treated as a strain.

What spondylolysis is

Spondylolysis is a stress injury, and eventually a stress fracture, of a small part of the vertebra called the pars interarticularis. The pars is a narrow bridge of bone at the back of each vertebra, most often affected at the lowest lumbar level. When the spine is repeatedly arched backward and twisted under load, that bridge takes a lot of stress. If the stress accumulates faster than the bone can repair, it starts to fail, in the same way a metatarsal can develop a stress fracture in a runner.

The injury is unusually common in young athletes. In one often-cited series of adolescent athletes presenting with low back pain, nearly half were found to have a pars stress injury, compared with a small fraction of adults with the same complaint.¹ It's especially common in sports with repeated hyperextension: gymnastics, figure skating, diving, cricket bowling, football linemen, and in our part of the world, hockey. Goalies and skaters who arch and rotate repeatedly fit the pattern well.

The pars can also be a developmental defect present long before any sport, and many people walk around with a pars defect and no symptoms at all. A long-running natural history study found that a pars defect present in childhood rarely progressed and was not associated with more back pain in adulthood.² So the finding itself isn't the concern. The concern is an active, painful stress reaction in a growing athlete, which needs rest from the provoking load to heal.

How it tends to present

There's no single sign that confirms it, but the pattern is fairly recognizable:

• Low back pain that builds over weeks rather than starting with one incident
• Pain worse with extension: arching back, standing after sitting, the back half of a skating stride, back walkovers, serving in volleyball
• Pain often on one side, sometimes referring into the buttock, rarely below the knee
• Relief with rest and recurrence when sport resumes
• Tight hamstrings on examination, which is common and nonspecific

A clinician will typically test extension on one leg and compare sides, though this test on its own is not reliable enough to rule the injury in or out.³ The history usually carries more weight than any single test. Red flags such as night pain, fever, unexplained weight loss, or neurological changes point to other diagnoses and need medical referral; we've written separately about when back pain warrants more concern.

The imaging question

This is one of the situations where imaging matters, which is different from most adult back pain. A plain X-ray can miss an early stress reaction. MRI is the usual next step because it can show bone marrow swelling in the pars before a fracture line appears, which is exactly the stage where healing is most likely.³ If a young athlete has extension-related back pain lasting more than two or three weeks, a referral to their physician for imaging is reasonable, and we'll generally make that recommendation early rather than waiting.

Managing a confirmed case is a team effort. It typically involves the family physician or a sports medicine physician, sometimes a pediatric orthopaedic specialist, and the rehab clinician who guides the return to sport.

What management looks like

The core of treatment is removing the load that caused the injury for long enough to let the bone settle. That usually means a period away from the sport and from extension-based activity, often measured in months rather than weeks, with the length guided by symptoms and the imaging stage.⁴ Bracing is sometimes used; the evidence for it is mixed, and many athletes do well with activity modification alone.

Rest from the sport is not rest from everything. Early on, the goal is to keep the athlete conditioned with things that don't stress the pars: cycling, swimming without hyperextension, upper body and lower body strength work in neutral spine positions. As pain settles, we progressively load the trunk and hips, building the capacity to control extension so the pars isn't absorbing load the hips and trunk should be sharing. This is the same philosophy we apply to any bone stress injury, where the bone needs a break but the athlete doesn't.

Return to sport is graded, not sudden. Skating comes back before full practice, practice before games, and extension-heavy skills last. The underlying lesson for young athletes is the same one that runs through most of what we see in adolescent and adult back pain: there are no bad movements, only too much too soon,⁵ and a growing spine has less margin for that than a mature one. Year-round single-sport training, which we've discussed in our post on early specialization, is one of the strongest risk factors.

Most young athletes with spondylolysis return fully to their sport. The ones who struggle are usually the ones whose pain was managed as a strain for months while they kept playing. If a young athlete's back pain has lasted more than a few weeks and gets worse with arching, it's worth asking the question early.

References

1. Micheli LJ, Wood R. Back pain in young athletes: significant differences from adults in causes and patterns. Arch Pediatr Adolesc Med. 1995;149(1):15-18.
2. Fredrickson BE, Baker D, McHolick WJ, Yuan HA, Lubicky JP. The natural history of spondylolysis and spondylolisthesis. J Bone Joint Surg Am. 1984;66(5):699-707.
3. Masci L, Pike J, Malara F, Phillips B, Bennell K, Brukner P. Use of the one-legged hyperextension test and magnetic resonance imaging in the diagnosis of active spondylolysis. Br J Sports Med. 2006;40(11):940-946.
4. Standaert CJ, Herring SA. Spondylolysis: a critical review. Br J Sports Med. 2000;34(6):415-422.
5. Gabbett TJ. The training-injury prevention paradox: should athletes be training smarter and harder? Br J Sports Med. 2016;50(5):273-280.