Hamstring injury patterns in professional male football (soccer): a systematic video analysis of 52 cas

ObjectiveTo closely describe the injury inciting events of acute hamstring injuries in professional male football (soccer) using systematic video analysis.MethodsVideo footage from four seasons (2014–2019) of the two highest divisions in German male football was searched for moderate and severe (ie, time loss of >7 days) acute non-contact and indirect contact match hamstring injuries. Two raters independently categorised inciting events using a standardised procedure to determine specific injury patterns and kinematics.Results52 cases of hamstring injuries were included for specific pattern analysis. The pattern analysis revealed 25 sprint-related (48%) and 27 stretch-related hamstring injuries (52%). All sprint-related hamstring injuries occured during linear acceleration or high-speed running. Stretch-related hamstring injuries were connected with closed chain movements like braking or stopping with a lunging or landing action and open chain movements like kicking. The kinematic analysis of stretch-related injuries revealed a change of movement involving knee flexion to knee extension and a knee angle of <45° at the assumed injury frame in all open and closed chain movements. Biceps femoris was the most affected muscle (79%) of all included cases.ConclusionDespite the variety of inciting events, rapid movements with high eccentric demands of the posterior thigh are likely the main hamstring injury mechanism. This study provides important data about how hamstring injuries occur in professional male football and supports the need for demand-specific multicomponent risk reduction programmes.

Evidence-Based Management and Factors Associated With Return to Play After Acute Hamstring Injury in Athletes: A Systematic Review

Background: Considering the lengthy recovery and high recurrence risk after a hamstring injury, effective rehabilitation and accurate prognosis are fundamental to timely and safe return to play (RTP) for athletes. Purpose: To analyze methods of rehabilitation for acute proximal and muscular hamstring injuries and summarize prognostic factors associated with RTP. Study Design: Systematic review; Level of evidence, 4. Methods: In August 2020, MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials, and SPORTDiscus were queried for studies examining management and factors affecting RTP after acute hamstring injury. Included were randomized controlled trials, cohort studies, case-control studies, and case series appraising treatment effects on RTP, reinjury rate, strength, flexibility, hamstrings-to-quadriceps ratio, or functional assessment, as well as studies associating clinical and magnetic resonance imaging factors with RTP. Risk of bias was assessed using the Cochrane Risk-of-Bias Tool for Randomized Trials or the Methodological Index for Non-Randomized Studies (MINORS). Results: Of 1289 identified articles, 75 were included. The comparative and noncomparative studies earned MINORS scores of 18.8 ± 1.3 and 11.4 ± 3.4, respectively, and 12 of the 17 randomized controlled trials exhibited low risk of bias. Collectively, studies of muscular injury included younger patients and a greater proportion of male athletes compared with studies of proximal injury. Surgery for proximal hamstring ruptures achieved superior outcomes to nonoperative treatment, whereas physiotherapy incorporating eccentric training, progressive agility, and trunk stabilization restored function and hastened RTP after muscular injuries. Platelet-rich plasma injection for muscular injury yielded inconsistent results. The following initial clinical findings were associated with delayed RTP: greater passive knee extension of the uninjured leg, greater knee extension peak torque angle, biceps femoris injury, greater pain at injury and initial examination, “popping” sound, bruising, and pain on resisted knee flexion. Imaging factors associated with delayed RTP included magnetic resonance imaging-positive injury, longer lesion relative to patient height, greater muscle/tendon involvement, complete central tendon or myotendinous junction rupture, and greater number of muscles injured. Conclusion: Surgery enabled earlier RTP and improved strength and flexibility for proximal hamstring injuries, while muscular injuries were effectively managed nonoperatively. Rehabilitation and athlete expectations may be managed by considering several suitable prognostic factors derived from initial clinical and imaging examination.

Hamstrung: Do Sex Differences in Hamstring Injury Profile Necessitate a Different Approach to Rehabilitation and Prevention Programs in Female Athletes?

Hamstring strain injury (HSI) is one of the most common injuries encountered in running sports and can lead to significant morbidity, with time lost from participation and high rates of recurrence. Though the incidence is high in both sexes, male athletes appear to have a two to four-fold greater risk of HSI compared to female athletes, with a longer recovery. Multiple potential risk factors have been studied and age, history of hamstring injury, ACL injury and calf injury appear to be the most significant factors in predicting index injury and recurrence. Female athletes may be relatively protected by less hamstring unit stiffness and greater muscle endurance. Other potential sex-influenced risk factors including differences in pelvic, hip and knee structural morphology and limb alignment, musculotendinous flexibility and joint mobility, and kinetic chain (primary posterior) strength imbalances require further investigation. Further research focusing both exclusively on female athlete as well as more robust comparative studies with male athletes will help us to better understand differences in HSI profile. Future investigation is necessary to determine whether a sex-specific approach to HSI rehabilitation and prevention programs will optimize clinical care for both male and female athletes.