Exploring the associations between ankle dorsal and plantar flexion strength, reactive strength index, and balance in elite youth soccer players

Background: Enhanced muscular strength has been widely acknowledged as a fundamental determinant of improved performance in the lower extremities. However, the specific impact of ankle strength on explosive strength and balance remains inadequately elucidated. Consequently, this study aims to (a) evaluate balance, reactive power, and flexor–extensor muscle balances in soccer players, and (b) evaluate ankle dorsal and plantar flexion muscle strength as predictive factors for reactive strength index and balance performance. Methodology: A cohort comprising 38 actively engaged Turkish National League soccer players participated in the study. The assessment encompassed explosive power through a drop jump, dynamic balance utilizing a moving disc, and ankle strength measured with a handheld dynamometer. Results: The findings revealed that dominant lower limb dorsal flexion strength emerged as a significant predictor of both reactive strength (R2 = 0.106, p < 0.05) and balance (R2 = 0.121, p < 0.05). Similarly, non-dominant lower limb dorsal flexion strength was identified as a significant predictor of reactive strength (R2 = 0.362, p < 0.05). Furthermore, the study established that dominant lower limb plantar flexion strength significantly predicted balance (R2 = 0.121, p < 0.05), while non-dominant lower limb plantar flexion strength served as a significant predictor of both reactive strength (R2 = 0.148, p < 0.05) and balance (R2 = 0.179, p < 0.05). Conclusions: Consequently, these findings emphasize the significance of incorporating targeted exercises designed to enhance intrinsic foot musculature, thereby augmenting both explosive strength and balance in athletes. While acknowledging the persistent importance of strength assessment in evaluating lower extremity performance, our results underscore the critical role played by ankle muscle strength in the execution of explosive strength and balance.