Author(s): STEINBERG, N., ELBAZ, L., ELIAKIM, A., NEMET, D., DAR, G., Institution: WINGATE ACADEMIC COLLEGE, Country: ISRAEL, Abstract-ID: 178

INTRODUCTION:
Tibial bone stress injuries (BSIs) are common lower leg injuries in gymnasts1. Risk factors include anatomical misalignments, reduced lower-leg muscle strength, training errors and inadequate nutrition2-3. Since stress fractures are particularly concerning during adolescence—a critical period for bone mass acquisition — the implications for young athletes entering puberty are significant. The current study aimed to examine the prevalence of gymnasts with BSIs and its relationship with anthropometric measures, muscle strength, bone status and pubertal stage during the two years follow-up.
METHODS:
One-hundred twenty-nine female competitive gymnasts (aged 11.6±1.8yrs) were clinically evaluated at baseline, after one-year (first follow-up) and after two-years (second follow-up) for BSIs, anthropometrics, training-volume, bone-status (as measured by SOS), muscle-strength and pubertal status (measured by Tanner stages and divided into pre-pubertal, entering-puberty during follow-ups, and late-pubertal).
RESULTS:
Prevalence of BSIs was significantly higher in pre-pubertal (64.7%) compared to entering-puberty (30.9%) and late-pubertal gymnasts (4.4%) (p=0.032). Tibial-strength and muscle-strength were significantly higher in gymnasts with no-BSIs compared with those with ≥2 episodes of BSIs (BSIs in two or three of the assessments) (p<0.001 and p<0.05, respectively). Two-way ANOVA with repeated measures show significant interactions (timeXBSIs) for bone-status (F(2, 254)=4.296, p=0.015), and for plantar-flexors and knee-extensors muscle-strength (p=0.019 and p=0.002, respectively). Nominal regression showed that reduced tibial-strength, reduced plantar-flexors muscle strength, pre-puberty and entering-puberty differentiated between participants with ≥2 episodes of BSIs and non-injured participants (p<0.05).
CONCLUSION:
High prevalence of elite young female gymnasts suffered from BSIs. Pre-pubertal gymnasts had the highest prevalence compared who experienced puberty during follow-up and those who were already pubertal at baseline. Decreased tibial bone status, decreased ankle plantar-flexors muscle strength, and being pre- or entering-puberty were parameters associated with BSIs in two or three of the assessments. This study provides valuable data that can guide trainers and medical teams treating young female gymnasts in screening, managing and preventing injuries like tibial BSIs.

References:
1. Rizzone KH, Ackerman KE, Roos KG, et al. The Epidemiology of Stress Fractures in Collegiate Student-Athletes, 2004-2005 Through 2013-2014 Academic Years. J Athl Train 2017;52(10):966-75.
2. Lauersen JB, Andersen TE, Andersen LB. Strength training as superior, dose-dependent and safe prevention of acute and overuse sports injuries: a systematic review, qualitative analysis and meta-analysis. Br J Sports Med 2018;52(24):1557-63.
3. Beck B, Drysdale L. Risk Factors, Diagnosis and Management of Bone Stress Injuries in Adolescent Athletes: A Narrative Review. Sports (Basel) 2021;9(4).