Non-contact Lower Limb Injuries Research Articles

Lower Quarter Y-Balance Test Anterior Reach Asymmetry and Noncontact Lower Limb Injury in Subelite Young Male Soccer Players With Different Training Experiences

Poor single-leg balance performance is associated with an increased risk of sustaining lower limb injuries in team sports. However, it is unclear whether this relationship is modified by the level of training experience (years of training experience). The objective of the present study was to evaluate whether soccer players’ single-leg balance performance is related to lower limb injuries in noncontact situations with different levels of training experience. Subelite young male soccer players performed the Lower Quarter Y-Balance Test with the dominant and the nondominant leg at the beginning of the preseason. Due to COVID-19 rules, the occurrence of lower limb injuries during the second half of the competitive season was documented. The odds of injury were calculated based on a previously reported Lower Quarter Y-Balance Test cut-off score for side-to-side anterior reach difference (≥4 cm). Twelve soccer players sustained a lower leg injury in noncontact situations. Only four of them had an anterior reach difference equal to or above the cut-off score. Soccer training experience has no significant influence on the association between Lower Quarter Y-Balance Test anterior reach asymmetry and noncontact lower limb injury in young male players.

Identification of potential risk factors for lower limb injuries in female team-sport athletes: a prospective cohort study

ABSTRACT Objectives The purpose of this prospective cohort study was to assess the associations between lower limb injuries in female team-sport athletes and a number of factors. The potential risk factors explored included (1) lower limb strength, (2) history of life-event stress, (3) family history of ACL injuries, (4) menstrual history, and (5) history of oral contraception use. Methods One hundred and thirty-five female athletes aged between 14 and 31 years (mean: 18.8 ± 3.6 years) from rugby union (n = 47), soccer (n = 72), and netball (n = 16) volunteered to participate in this study. Demographics, history of life-event stress, injury history and baseline data were obtained prior to the competitive season. The following strength measures were collected: isometric hip adductor and abductor strength, eccentric knee flexor strength and single leg jumping kinetics. Athletes were then followed for 12 months, and all lower limb injuries sustained were recorded. Results One hundred and nine athletes provided one-year follow-up injury data, of whom, 44 suffered at least one lower limb injury. All athletes who reported high scores for negative life-event stress sustained lower limb injuries. Non-contact lower limb injury was positively associated with weak hip adductor strength (OR: 0.88; 95%CI: 0.78–0.98; p = 0.017), and between-limb adductor (OR: 5.65; 95%CI: 1.61–19.7.; p = 0.007) and abductor (OR: 1.95; 95%CI: 1.03–3.71; p = 0.039) strength asymmetries. Conclusion History of life event stress, hip adductor strength, and between-limb adductor and abductor strength asymmetries offer potential novel avenues for investigating injury risk factors in female athletes.

Relationships between trunk morphology and strength with non-contact lower limb injuries in elite rugby league and Australian football players

Background: Non-contact lower limb injuries (NCLLI) are common within the National Rugby League (NRL) and Australian Football League (AFL). Smaller lumbar multifidus at L5 (LM L5) cross-sectional area (CSA) and lower levels of trunk and hip extension and knee flexion strength have been associated with increased NCLLI risk in AFL players. However, such associations have not been reported in the NRL. This study aims to explore relationships between NCLLI, trunk morphology and isometric trunk and hip extension strength in NRL and AFL players. Methods: NRL and AFL players had their LM L2-L5 and quadratus lumborum (QL) CSA (n=238), and isometric trunk and hip extension strength (n=153) measured using ultrasonography and a novel field-based test in preseason. Isometric trunk and hip extensor strength were measured using a 65s maximal voluntary isometric contraction (MVIC) protocol (5s MVIC, 5s off, 45s MVIC, 5s off, 5s MVIC). Team medical staff reported all NCLLIs sustained in the subsequent competitive season. The associations between LM and QL CSA, 5s and 45s MVIC, age, and previous injury, and prospectively occurring NCLLI were analysed using univariable and then multivariable logistic regression. Logistic regression analysis was also performed for the most sustained NCLLI (hamstring and knee). Results: Seventy-two players sustained a NCLLI in the 2020 competitive seasons (51 NRL, 21 AFL). From univariable logistic regression previous injury increased the risk of any NCLLI in NRL (OR=2.43, 95%CI=1.16-5.09, p=0.019). Reduced 5s MVIC (OR=1.00, 95%CI=1.00-1.01, p=0.012), increased QL CSA (OR=1.55, 95%CI=1.05-2.38, p=0.033) and lower ratio between LM and QL CSA (OR=0.03, 95%CI=0.01-0.60, p=0.02) increased NCLLI risk in AFL. Pooled hamstring injuries (n=28) were most common and were associated with lower 5s MVIC (OR=0.99, 95%CI=0.99-1.00, p=0.02) and 45s MVIC (OR=0.99, 95%CI=0.99-1.00, p=0.001). Pooled knee injuries (n=21) were associated with both reduced LM CSA (OR=1.35, 95%CI=1.08-1.70, p=0.018) and LM to QL ratio (OR=3.62, 95%CI=1.41- 9.66, p=0.043). Conclusions: Larger QL CSA and reduced levels of trunk and hip extension strength are observed in AFL players in preseason who sustain a NCLLI in the subsequent playing season. Only previous NCLLI was associated with future risk of NCLLI for NRL players. These results suggest that risk factors for NCLLI are football code specific, and prevention strategies should be tailored accordingly. Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest relevant to the submission of this abstract.

Relationship between Posture and Non-Contact Lower Limb Injury in Young Male Amateur Football Players: A Prospective Cohort Study.

Posture, a potentially modifiable injury risk factor, is considered important in injury screening/prevention in athletes, yet few studies investigate relationships between posture and injury. This prospective cohort study investigated whether static posture is associated with lower limb injury risk in male football players (n = 263). Nine aspects of static standing posture (left and right rearfoot, knee interspace, lateral knee, lumbar lordosis, thoracic kyphosis, scoliosis S and C, forward head) were assessed from photographs during the pre-season using the modified Watson and Mac Donncha scale, which was dichotomised for analysis (deviated or normal). Player characteristics (age, height, mass, body mass index, competition level), match/training exposure, and previous and in-season non-contact lower limb injuries were recorded. Binary logistic regression investigated relationships between posture and injury (previous and in-season). Eighty previous and 24 in-season lower limb injuries were recorded. Previous injury was not associated with any postural variable. In-season injury was associated with previous injury (OR = 3.04, 95% CI 1.20–7.68, p = 0.02) and having a normal thoracic curve compared to kyphosis (OR = 0.38, 95% CI 0.15–1.00, p = 0.05) but no other postural variables. Static postural deviations observed in male football players in the pre-season are not typically associated with non-contact lower limb injury risk; thus, they are unlikely to add value to pre-season screening programs.

Relationships Among PlayerLoad, High-Intensity Intermittent Running Ability, and Injury Risk in Professional Rugby League Players.

To examine relationships among physical performance, workload, and injury risk in professional rugby league players. Maximal-effort (n = 112) and submaximal (n = 1084) running performances of 45 players were recorded from 1 club over 2 consecutive seasons. Poorer and better submaximal running performance was determined by higher and lower exercise heart rates, respectively. Exponentially weighted moving averages and daily rolling averages were used to assess microtechnology-derived acute and chronic field-based workloads. The associations among within-individual submaximal running performance, workload, and noncontact lower-limb injury were then investigated. The injury risk associated with poorer submaximal performance was "likely" greater than stable (relative risk = 1.8; 90% confidence interval, 0.9-3.7) and better submaximal performance (relative risk = 2.0; 90% confidence interval, 0.9-4.4). Compared with greater submaximal performance, poorer performance was associated with lower chronic workloads (effect size [d] = 0.82 [0.13], large) and higher acute:chronic workload ratios (d = 0.49 [0.14], small). Chronic workload demonstrated a "nearly perfect" positive relationship with maximal-effort running performance (exponentially weighted moving average, R2 = .91 [.15]; rolling average, R2 = .91 [.14]). At acute:chronic workload ratios >1.9, no differences in injury risk were found between rolling average and exponentially weighted moving average methods (relative risk = 1.1; 90% confidence interval, 0.3-3.8; unclear). Reductions in submaximal running performance are related with low chronic workloads, high acute:chronic workload ratios, and increased injury risk. These findings demonstrate that a submaximal running assessment can be used to provide information on physical performance and injury risk in professional rugby league players.

Session Availability as a Result of Prior Injury Impacts the Risk of Subsequent Non-contact Lower Limb Injury in Elite Male Australian Footballers.

Prior injury is a commonly identified risk factor for subsequent injury. However, a binary approach to classifying prior injury (i.e., yes/no) is commonly implemented and may constrain scientific findings, as it is possible that variations in the amount of time lost due to an injury will impact subsequent injury risk to differing degrees. Accordingly, this study investigated whether session availability, a surrogate marker of prior injury, influenced the risk of subsequent non-contact lower limb injury in Australian footballers. Data were collected from 62 male elite Australian footballers throughout the 2015, 2016, and 2017 Australian Football League seasons. Each athlete’s participation status (i.e., full or missed/modified) and any injuries that occurred during training sessions/matches were recorded. As the focus of the current study was prior injury, any training sessions/matches that were missed due to reasons other than an injury (e.g., load management, illness and personal reasons) were removed from the data prior to all analyses. For every Monday during the in-season periods, session availability (%) in the prior 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, and 84 days was determined as the number of training sessions/matches fully completed (injury free) relative to the number of training sessions/matches possible in each window. Each variable was modeled using logistic regression to determine its impact on subsequent injury risk. Throughout the study period, 173 non-contact lower limb injuries that resulted in at least one missed/modified training session or match during the in-season periods occurred. Greater availability in the prior 7 days increased injury probabilities by up to 4.4%. The impact of session availability on subsequent injury risk diminished with expanding windows (i.e., availability in the prior 14 days through to the prior 84 days). Lesser availability in the prior 84 days increased injury probabilities by up to 14.1%, only when coupled with greater availability in the prior 7 days. Session availability may provide an informative marker of the impact of prior injury on subsequent injury risk and can be used by coaches and clinicians to guide the progression of training, particularly for athletes that are returning from long periods of injury.