Modified defense reaction reduces biomechanical and myoelectrical ACL injury risk factors in elite Judo

Direct contact and very rapid valgus distortion characterise the injury mechanism of anterior cruciate ligament ruptures in judo

PURPOSE

To analyse anterior cruciate ligament (ACL) rupture (ACLR) injury mechanisms in competitive judo using systematic video analysis, focusing on contact situations and biomechanics.

METHODS

Seventeen videos of judo competitions wherein athletes developed ACLRs were included and retrospectively evaluated by five analysts. In all videos, the moment of initial contact and the index frame were defined. The judo techniques leading to the injury; the occurrence of direct contact, indirect contact or noncontact mechanisms; the time interval between the initial contact and index frame; the positions of the hip, knee and foot in relation to the initial contact and index frame; and the balance status during the initial contact and index frame were recorded.

RESULTS

Eleven (65%) of ACLRs in judo involved direct contact. The mean time interval between initial contact and index frame was 15 ± 22 ms. Thirteen (77%) athletes were not balanced at initial contact. In the index frame, the hip was abducted in all cases and in combination with internal rotation in 12 (71%) cases. From initial contact to index frame, hip flexion increased in all cases; at index frame, the knee joint was internally rotated relative to the trunk in 12 (71%) cases, and the knee flexion angles increased from the initial contact. In the index frame, the foot was externally rotated relative to the knee in 12 (71%) cases, and severe valgus development of the knee with valgus collapse was observed in 14 (82%) cases.

CONCLUSIONS

A direct attack on the knee was the most common injury mechanism observed. Valgus distortion appears to be the most important component of the mechanism of injury. With this knowledge, 'modified defence reactions' for specific judo techniques can be developed to reduce the injury risk.

LEVEL OF EVIDENCE

Level IV.

Isometric and isokinetic strength of lower-limb muscles in female athletes during different phases of menstrual cycle: a causal-comparative study

BACKGROUND

Muscle strength is affected by different stages of the menstrual cycle in women. Since the strength of the lower limb muscles plays a significant role in the occurrence of anterior cruciate ligament injury, it seems necessary to study the strength of the lower limb muscles at different stages of this cycle to take preventive measures. Therefore, this study aimed to compare the isometric and isokinetic strength of lower limb muscles in female athletes at different menstrual cycle stages.

METHODS

The present study is of a causal-comparative type. Thirty-seven female athletes in anterior cruciate ligament injury high-risk disciplines participated in this study. Isometric and isokinetic knee extensors and flexors muscle strength status, including the traditional hamstrings/quadriceps (H/Q) ratios, were recorded at different stages of the menstrual cycle (follicular, ovulatory, luteal) by Biodex isokinetic dynamometry system 4. Then, the obtained results were analyzed by repeated measure analysis of variance.

RESULTS

Analysis of variance with repeated measures showed isokinetic and isometric strength in the knee flexor and extensor muscles at an angular velocity of 60˚/s in the ovulatory phase are higher than the follicular and luteal ones. The strength of the muscles declined during the follicular and luteal phases (p ≤ 0.05).

CONCLUSIONS

Due to the negative effect of the follicular and luteal stages of the menstrual cycle on the strength of the flexor and extensor muscles of the knee, the risk of anterior cruciate ligament injury may increase during this period. Therefore, it is recommended that all female coaches and athletes take preventive measures during this period.

A-trait and risk-taking behavior in predicting injury severity among martial arts athletes

Introduction

Trait anxiety (A-trait) can be seen as a multiplicative function of the person-situation interaction. Considering risk-taking behavior (R-TB), literature highlights instrumental and stimulating risk. The aim of the research is to investigate the level of A-trait (in physically dangerous conditions and in new, unusual situations) and the level of R-TB (instrumental and stimulating risk) in athletes, and to verify to what extent A-trait and risk-taking behavior predict injury severity.

Materials and methods

One hundred and fifty-four senior martial arts athletes from grappling combat sports, striking combat sports and mixed martial artists (MMA) participated in the study. For assessing trait anxiety and risk-taking behavior, the Romanian adaptation of the Endler Multidimensional Anxiety Scales (EMAS), respectively the Romanian adaptation of the Makarowski's Stimulating and Instrumental Risk Questionnaire were used.

Results

Using multivariate analysis of variance, significant differences between athletes (according to the sports disciplines practiced), in terms of A-trait and R-TB, were examined. Next, we checked the existing correlations between injury severity, A-trait and R-TB scores in athletes practicing striking combat sports, grappling combat sports and MMA. To verify whether there are significant differences in terms of trait anxiety, stimulating and instrumental risk between athletes who have suffered mild, moderate and/or severe injuries and athletes who have suffered only minor/mild injuries, t-Test for Independent Samples was used. Binomial logistic regression procedures were, also, performed, predicting athletes' likelihood of injury, based on R-TB and A-trait.

Conclusion

A moderate or slightly below average level of anxiety in new, unusual situations and a higher level of instrumental risk are linked with a decreased likelihood of severe injuries in athletes. Martial arts athletes (in entire sample) who have suffered more severe injuries are more adrenaline-seeking in competition and use less rational thinking, taking more pleasure in just performing technical executions, regardless of the outcome.