A comparison of hip adduction to abduction strength ratios, in the dominant and non-dominant limb, of elite academy football players

Abstract

Context: Hip adduction and abduction strength plays an important role in the treatment and prevention of groin injuries in football players. Currently there are no reliable baseline values for uninjured football player’s hip adduction: abduction muscle strength ratios. Objective: To examine whether normal hip adduction: abduction strength ratios can be established in uninjured football players.  To compare this data, and establish if there is an asymmetry between the dominant and non-dominant limb. Methods: Twenty, English Premier League academy football players 18.45 (± 2.06) years, 72.6 (± 5.56) kg, 180.15 (± 7.97) cm, 3 left limb dominant, and 17 right limb dominant were included in the study. Eccentric and concentric hip adduction and abduction strength of the dominant and non-dominant leg was tested using a Cybex isokinetic dynamometer. Results: The concentric ratio on the dominant limb was 1.59 (± 0.19) and on the non-dominant limb 1.45 (± 0.31).  The eccentric ratio on the dominant limb was 1.45 (± 0.32) and on the non-dominant limb 1.26 (± 0.26).  Overall the ratios were higher on the dominant limb and this was statistically significant P ≤ .05. Abduction strength was similar bilaterally.  Adduction strength was 18%-22% greater on the dominant limb. Conclusions: The greater ratios on the dominant limb are due to increased adductor strength as a result of the kicking action. Elite football player’s hip adduction: abduction strength ratios should be 1.45-1.6 on the dominant limb and 1.25-1.45 on the non-dominant limb. The adductors on the dominant limb should be 18%-22% stronger than the non-dominant limb. Ratios outside these parameters could indicate the player is at risk of injury. Further research is required to support muscle imbalance as a cause of injury and identify injury risk thresholds for groin injuries in football players.