Comparison of hip abductor strength in pre-professional ballet dancers with and without snapping hip

Abstract

Objective: To compare hip abductor muscle strength in ballet dancers with and without snapping hip syndrome and to evaluate the correlation between Hip and Groin Outcome Score (HAGOS) sub-scores and snapping intensity Material and Methods: A cross-sectional study was conducted in randomly selected dancers, allocated to 3 groups according to their assessment by anterior hip pain or snapping in physical examination. The subjects completed the HAGOS survey. Subsequently, hip abductor strength was measured using a hand-held dynamometer. The study was carried out on a total of 70 pre-professional ballet dancers (140 hips, aged 16-20). Participants classified into three groups based on medical history and physical examination (G1: pain (-) snapping (-); G2: pain (-), snapping (+); G3: snapping (+) and pain (+)). Secondly, all hips were classified into three groups (H1: pain (-), snapping (-), H2: pain (-), snapping (+), H3: pain (+), snapping (+). Snapping intensity in participants rated by the frequency of snapping (between level 0-4) according to their self-report. Differences were assessed between dancers and hips with snapping hip and without snapping hip. Results: There was no difference in hip abductor strength levels between three hip groups (p=0.446). However, significant differences were observed in mHAGOS, pHAGOS, sHAGOS mean values between the three (G1, G2, G3) groups (p<0,001; p<0,001; p<0,001, respectively). sHAGOS, pHAGOS and mHAGOS mean values were significantly higher in G1 and G2 when compared to G3. Besides, there were negative correlation between snapping intensity and mHAGOS (p=0.002, rho=-0.37), pHAGOS (p=0.001, rho=-0.39) and sHAGOS (p=<0.001, rho=-0.55). Conclusion: Hip abductor strength levels were not significantly affected by the presence of snapping in dancers; further investigation is needed in this regard. However, the results revealed that HAGOS sub-scores and snapping intensity is related. HAGOS questionnaire might be implemented to the dancers as a preseason screening method for snapping hip.