”Hand reach star excursion balance test” : Assessment of dynamic functional mobility in female elite team gymnasts in relation to overuse injuries

Abstract: Background Clinical usable assessment methods to quantify mobility, balance, stability and postural control functions together in a full kinetic chain movement are sparse. Normative data of such dynamic functions in different group of athletes are  still lacking and therefore the relationship between dynamic functional mobility and overuse injuries are also unknown. The prevalence of overuse injuries among adolescent athletes are continuously high and team gymnastic is one example of a sport with multiple and underestimated overuse injuries.   Aim The first aim of study was to establish normative data of dynamic functional mobility in a group of elite team gymnasts. The second aim was to investigate ongoing overuse injuries and evaluate associations between ongoing overuse injuries and dynamic functional mobility in the group.   Method A descriptive cross sectional study including 31 female elite team gymnasts 16-19 years old were conducted. “The hand reach star excursion balance test” (HSEBT) was used to measure dynamic functional mobility in 20 different movement patterns. The "Oslo Sports Trauma Research Center Overuse Injury Questionnaire"(OSTRC) was used to record and analyse severity of ongoing overuse injuries in the group. Pearson correlation analysis was used to determine the relationship between the scoring in the HSEBT- tests and scoring on the OSTRC.   Results A majority of the participants presented with scores near the maximum values on the HSEBT. Further,  97% of the subjects had an ongoing overuse injury. Severe injuries, affecting participation in sport were present in 67%. Correlations was found between prevalence of severe injury in the lower back and lower scoring on the right leg in a rotational movement pattern (r= -0,42) whereas prevalence of severe injury in the hip was associated with extreme high mobility in a sidebending pattern in both legs (r= 0,50, 0,49). There was also a relationship between individuals with multiple severe overuse injuries and dynamic functional mobility in an extended movement pattern of the left leg (r= -0,36, -0,38).   Conclusion Normative data of dynamic functional mobility according to the HSEBT can provide clinicians with reference points to compare elite female team gymnasts. There was an indication of association between limited mobility in some of the included tests and prevalence of overuse injuries in the lower back and hip. This study included a small sample and therefore conclusions have to be interpreted carefully.