Prediction of hamstring injury in professional soccer players by isokinetic measurements

Abstract

SummaryObjectives: previous studies investigating the ability of isokinetic strength ratios to predict hamstring injuries in soccer players have reported conflicting results. Hypothesis: to determine if isokinetic ratios are able to predict hamstring injury occurring during the season in professional soccer players. Study Design: case-control study; Level of evidence: 3. Methods: from 2001 to 2011, 350 isokinetic tests were performed in 136 professional soccer players at the beginning of the soccer season. Fifty-seven players suffered hamstring injury during the season that followed the isokinetic tests. These players were compared with the 79 uninjured players. The bilateral concentric ratio (hamstring-to-hamstring), ipsilateral concentric ratio (hamstring-toquadriceps), and mixed ratio (eccentric/concentric hamstring-to-quadriceps) were studied. The predictive ability of each ratio was established based on the likelihood ratio and post-test probability. Results: the mixed ratio (30 eccentric/240 concentric hamstring-to-quadriceps) <0.8, ipsilateral ratio (180 concentric hamstring-to-quadriceps) <0.47, and bilateral ratio (60 concentric hamstring-to-hamstring) <0.85 were the most predictive of hamstring injury. The ipsilateral ratio <0.47 allowed prediction of the severity of the hamstring injury, and was also influenced by the length of time since administration of the isokinetic tests. Conclusion: isokinetic ratios are useful for predicting the likelihood of hamstring injury in professional soccer players during the competitive season.

Peak Isokinetic Torques of Football Players Participating in Different Levels in Cyprus and Lower Limb Asymmetries

“…Conventional H:Q ratios range from 0.6 to 0.9 [14] with such ratios rising when testing at higher velocities [15]. Ratios below 0.8 have been reported to increase the likelihood of sustaining a hamstring injury [12]. Although not a statistically significant finding, 18 players, accounting for the 4% of the total number of participants, displayed H/Q ratios of less than 0.6.…”

“…This was found to be the case at all isokinetic speeds except at 300 °/sec, suggesting that hamstring strength plays an important role in joint balance and stabilization [13]. Research demonstrated that the probability of sustaining a hamstring injury is high if the concentric H/Q ratio, tested isokinetically at 60 °/sec, is less than 0.8 [12]. Conventional H: Q ratios range from 0.6 to 0.9 [14] with those ratios increasing when testing at higher velocities [15,16].…”

“…Asymmetries and weakness of the lower limbs were linked to increased rate of musculoskeletal injuries in elite football players [3,[9][10][11] with the rate of muscle injury being significantly greater in players with untreated imbalances compared to those with no imbalances [3,10]. Even though several investigators have suggested that asymmetries are linked to increased rate of musculoskeletal injuries in elite football players [3,11,12], strength adaptations in players with high professional training age was demonstrated to correlate with lower risk of football injuries [7,10].…”

“…When the quadriceps generates substantially greater forces than the hamstrings, excessive anterior translation may occur, especially during dynamic activities, such as those that involve sudden change in position. This may in turn, lead to both hamstring strain [12] and ACL injuries [18,19]. Hamstring strains accounts for 12% of the total injuries sustained over two seasons [20].…”

Isokinetic Assessment of Muscular Strength and Balance in Brazilian Elite Futsal Players

“…During isokinetic tests the athlete cannot perform a functional movement specific to a futsal match, however, this objective test may be important to identify strength asymmetries, which can relate to muscle injury risk that are common in high-intensity team sports. 20,21,38,42 To date, studies that evaluated peak isokinetic knee torque in futsal players have assessed strength performance or fatigue, 43 but not bilateral asymmetries.…”