Preventing Lumbar Stress Fractures: Keeping Young Athletes Safe this Summer.

By Will Dawson
Physiotherapist

With winter over and football boots scrubbed and stored away for another season, our attention shifts to summer sport. Whether your interests lie on a court, a cricket pitch or on the water, there are sports aplenty to enjoy in the sun. My eye is drawn to the summer of cricket, where the worlds top two ranked test teams do battle – Australia vs India. Beginning 22^nd Nov in Perth and culminating in the annual boxing day test at the MCG, it is sure to be an enthralling clash between the worlds predominate cricketing nations. However, the lead up to this series struck a sour note, when recent news broke that Cameron Green, Australia’s premier “all-rounder” will miss the series, and the remainder of the summer after suffering a lumbar stress fracture.

This news has prompted discussion on the nature the injury, its prevalence particularly among cricket players, and how to best prevent such an injury.

A stress fracture is an overuse injury caused when repetitive loading exceeds time for healing and recovery. In relation to the spine, when this bone recovery “lag” develops among vertebrae, and fatigue in surrounding stabilising structures increases, over time a “microfracture” may form, termed a stress fracture.

While symptoms vary, they typically include

• Spontaneous and often gradual increase in back pain that intensifies with activity and eases with rest.
• Pain with backward bending
• Possible pain referral down the leg and night pain.

Cricket fast bowlers such as Green, are at the highest risk of developing stress fractures localised to the lumbar spine. Fast bowling is a unique asymmetrical and forceful movement involving significant rotation and hyperextension prior to ball release. Elite athletes can be bowling as many as 30-40 overs in an innings of test match cricket, often on consecutive days. Repetitive loading of this complex movement sequence places undue stress to vulnerable aspects of the vertebrae, leading to these potential stress fractures, which typically occur on the opposite side to bowling hand dominance (i.e. left sided low back pain for the right-hand fast bowler).

Young cricketers experiencing pubescent changes are particularly susceptible with research showing that 18 months after maximum growth spurt presents the highest risk of bone stress injury. This is due to changes in bone growth and relative weakness in bone strength during this period (or “skeletal immaturity”), and compounded by increases in bowling loads as they transition through age, often to higher intensity competitions.

Australian cricket junior bowling guidelines released in 2023 state that between 20%-33% junior (<19 years of age) pace bowlers develop a lower back (lumbar) bone stress injury each season. While age and height are unmodifiable risk factors, monitoring bowling loads is key to reduce the risk of sustaining this type of injury. Adjusting bowling loads per week allows time to reduce fatigue before the next bowling session so the bone and tissues can adequately recover. Recommendations for this age demographic in the guidelines state for no more than:

• 5 overs each “spell”, 12 overs per matchday for u15’s
• 6 overs each “spell”, 16 overs per matchday for u17s
• 6 overs each “spell”, 18 overs per matchday U19s

Preparation should involve a gradual increase in bowling loads for a minimum of 10 weeks in the lead up to a season. In-season, a lighter bowling week every 4 weeks and a week off every 10-12 weeks is recommended. Coaching and biomechanical analysis of technique, as well as strength and conditioning programs could also be utilised as possible preventative interventions. Community cricket clubs and family members would benefit being familiar with these recommendations to reduce the risk of such a debilitating injury to young athletes.

It is important to note that spinal stress fractures are not limited to cricket fast bowlers –gymnasts, dancers, rowers, and track and field athletes, also demand repetitive backward bending and rotation, and load management should be adjusted accordingly in these respective sports.

If you, a friend or family member are involved in these sports and suspicious of a stress fracture, please consult a physiotherapist at Physiosports for expert advice and management.