Objective To determine whether individuals with a prior concussion exhibit biomechanical alterations in balance, gait and jump-landing tasks with and without cognitive demands that are associated with risk of lateral ankle sprain (LAS) and anterior cruciate ligament (ACL) injury. Design Systematic review and meta-analysis. Data sources Five electronic databases (Web of Science, Scopus, PubMed, SPORTDiscus and CiNAHL) were searched in April 2023. Eligibility criteria Included studies involved (1) concussed participants, (2) outcome measures of spatiotemporal, kinematic or kinetic data and (3) a comparison or the data necessary to compare biomechanical variables between individuals with and without concussion history or before and after a concussion. Results Twenty-seven studies were included involving 1544 participants (concussion group (n=757); non-concussion group (n=787)). Individuals with a recent concussion history (within 2 months) had decreased postural stability (g=0.34, 95% CI 0.20 to 0.49, p<0.001) and slower locomotion-related performance (g=0.26, 95% CI 0.11 to 0.41, p<0.001), both of which are associated with LAS injury risk. Furthermore, alterations in frontal plane kinetics (g=0.41, 95% CI 0.03 to 0.79, p=0.033) and sagittal plane kinematics (g=0.30, 95% CI 0.11 to 0.50, p=0.002) were observed in individuals approximately 2 years following concussion, both of which are associated with ACL injury risk. The moderator analyses indicated cognitive demands (ie, working memory, inhibitory control tasks) affected frontal plane kinematics (p=0.009), but not sagittal plane kinematics and locomotion-related performance, between the concussion and non-concussion groups. Conclusion Following a recent concussion, individuals display decreased postural stability and slower locomotion-related performance, both of which are associated with LAS injury risk. Moreover, individuals within 2 years following a concussion also adopt a more erect landing posture with greater knee internal adduction moment, both of which are associated with ACL injury risk. While adding cognitive demands to jump-landing tasks affected frontal plane kinematics during landing, the altered movement patterns in locomotion and sagittal plane kinematics postconcussion persisted regardless of additional cognitive demands. PROSPERO registration number CRD42021248916.

Athletic taping is widely used in sports to prevent injury. However, the effect of anterior cruciate ligament (ACL) protective taping on neuromuscular control during dynamic tasks remains unclear. Therefore, this study aimed to investigate the immediate effect of ACL protective taping on landing mechanics and muscle activations during side hops in healthy individuals. Fifteen healthy individuals (11 males and 4 females; age, 23.1 ± 1.4 years; height, 175.1 ± 10.4 cm; weight, 66.3 ± 11.2 kg) volunteered to participate in this study. Landing mechanics and muscle activations were measured while each participant performed single-leg hops side-to-side for ten repetitions with and without taping. An optical motion capture system and two force plates were used to collect the kinematic and kinetic data during the side hops. Surface electromyogram recordings were performed using a wireless electromyography system. Paired t-tests were performed to determine the differences in landing mechanics and muscle activations between the two conditions (taping and non-taping). The level of significance was set at p < 0.05. Compared with the non-taping condition, participants landed with a smaller knee abduction angle, greater knee external rotation angle, and smaller knee extensor moment in the taping condition. Given that greater knee abduction, internal rotation, and knee extension moment are associated with a greater risk of ACL injury, our findings suggest that ACL protective taping can have an immediate effect on dynamic knee stability. Clinicians should consider using ACL protective taping to facilitate the use of favorable landing mechanics for ACL injuries.

Background: Sport-related concussions (SRCs) have emerged as a global health concern in sports medicine. Effective injury prevention programs have the potential to reduce the risk of SRCs, but, their efficacy remains inconclusive. Therefore, the aim of this systematic review and meta-analysis was to evaluate the efficacy of injury prevention programs in preventing SRCs and to examine whether different intervention types (physical- vs. educational-based) and athletic exposure context (practice vs. match) influenced the efficacy of interventions. Methods: Six databases (PubMed, CINAHL, MEDLINE, SPORTDiscus, Scopus, and Embase databases) were searched in March 2024. Studies were included if (1) the physical training or educational intervention aimed to prevent SRC, (2) the incidence rate (IR) or other outcome data sufficient to calculate the IR for both the intervention and control groups were reported, and (3) the study employed a prospective design. Results: A total of eight studies were included in the analysis, involving 2571 participants (intervention group: n = 1281; control group: n = 1290). Current injury prevention programs primarily targeted male athletes in rugby, American Football, and soccer. The analysis revealed a significant reduction in SRC rate among athletes who received injury prevention programs (incidence rate ratio = 0.66, 95% CI [0.50–0.85], p = .002). The moderator analysis indicated that neither the type of intervention nor the exposure context significantly influenced the efficacy of the injury prevention programs. Conclusions: SRC prevention programs provided a significant protection effect, reducing injury rates by 34%. Importantly, their efficacy remains consistent across both physical training and educational-based programs, as well as in various exposure contexts. However, further prospective studies are needed to develop injury prevention protocols specifically for females and to investigate factors that may influence the efficacy of these interventions to enhance the prevention of SRC across various sports.

In the strength and conditioning field, a variety of training exercises are being applied to improve speed-related performance, but there is a lack of traditional strength training guides that can be used for training effectiveness. The aim of this study was to assess the impact of a six-week traditional strength training program on elite rugby players and explore the relationships between the one repetition maximum (1RM) of traditional strength exercises and athletic performance. Twenty elite rugby players (age = 30.5 ± 1.5 years, mass = 96.7 ± 16.6 kg, height = 179.3 ± 6.0 cm) completed the strength training program, and 1RM values for bench press, squat, deadlift, and power clean, along with athletic performance metrics (20 m and 40 m sprints, vertical jump, broad jump, Bronco test, L-run), were measured before and after the training period. Medium effect sizes were observed in the deadlift (p = 0.04, d = 0.49) and bench press (p = 0.019, d = 0.57) 1RM, while the squat exhibited a very large effect size (p < 0.001, d = 2.08). Both before and after training, greater power clean 1RM demonstrated a strong correlation with each athletic performance test. However, bench press 1RM, both pre-and post-training, did not significantly associate with functional performances (p > 0.05). Notably, power clean 1RM showed the strongest correlation with athletic performance; despite being the most significant improvement in squat 1RM after the six-week training period, it was not associated with athletic performance outcomes in rugby players. This study underscores the varied impact of specific strength exercises on athletic performance, emphasizing the distinct role of power clean 1RM in predicting speed-related performance in male rugby players.