Search Results (8)

Background: The Identification of Functional Ankle Instability (IdFAI) questionnaire is widely used to screen for functional ankle instability (FAI), but its link to objective landing kinetics in multidirectional sports like netball is not well-understood. This study aimed to (i) compare landing kinetics between idFAI stratified netball players, and (ii) examine associations between IdFAI scores with dynamic postural stability (DPS) indices and peak vertical ground reaction forces (PvGRF) during vertical drop landings. Methods: A cross-sectional exploratory study using a repeated-measures landing protocol was conducted on female university netball players (n = 24), stratified into FAI (n = 12) and non-FAI (n = 12) groups using the IdFAI (≥11 indicating possible FAI). Participants completed 18 unilateral drop jump landings in forward (FW), diagonal (DI), and lateral (LA) directions. Ground reaction forces (GRFs) were recorded to obtain DPS and PvGRF metrics (1000 Hz). Mann–Whitney U tests compared FAI groups, and Spearman correlations assessed associations (p < 0.05). Results: Players with FAI showed greater anteroposterior instability during LA landings (U = 33.5, p = 0.020, ES = 0.65). IdFAI scores correlated moderately with lateral anteroposterior deficits (rs = 0.473, p = 0.020, CI = 0.062–0.746). Conclusions: These findings suggest that players with greater FAI display increased anteroposterior instability during LA landings, with higher IdFAI scores moderately associated with these deficits. Despite the small exploratory, hypothesis-generating sample, the results emphasize the practical relevance of direction-targeted landing-stability training to improve DPS in vertical landings. This may provide insight into ankle-injury risk among FAI netball players, given that LA landings represent a documented ankle sprain mechanism. Full article

Inter-limb asymmetries may negatively affect performance and increase injury risk in team sports, but evidence in women’s futsal remains scarce. This study examined the relationship between inter-limb asymmetries in vertical (countermovement jump, CMJ), horizontal (standing broad jump, SBJ), and reactive (drop jump, DJ) tests, ankle dorsiflexion (DF), and change of direction (COD; 505, L-Run, V-Cut) with physical performance variables in adult female futsal players. Thirty-two highly trained athletes from the Spanish Women’s Second Division (age: 23.4 ± 4.8 years) completed a testing battery including bilateral and unilateral jumps, linear sprints (5, 10, 15 m), COD tests, and ankle dorsiflexion. Asymmetries were calculated as percentage differences between limbs, and their associations with unilateral performance were analyzed using Pearson’s correlations. The highest asymmetries were observed in DJ (15.7 ± 13.3%) and DF (15.3 ± 13.3%), whereas L-Run and 505 displayed the lowest values. Significant moderate negative correlations were found between SBJ asymmetry and right leg SBJ performance (r = −0.356, p < 0.05), and between DF asymmetry and right leg DF (r = −0.494, p < 0.01). No other meaningful associations were identified, and agreement in the direction of asymmetry across tests was generally slight. These findings highlight the task-specific nature of inter-limb asymmetries and suggest that diverse unilateral assessments are needed to comprehensively monitor imbalances and inform targeted training interventions in female futsal. Full article

Background and Objectives: The anterior cruciate ligament (ACL) is crucial for knee stability, preventing anterior displacement of the tibia and rotation relative to the femur. Despite ACL reconstruction (ACLR), residual instability is common, affecting knee function. Anterolateral ligament reconstruction (ALLR) alongside ACLR improves outcomes, as the ALL plays a significant role in rotational stability. This study aims to assess the clinical and functional outcomes of the ACLR+ALLR combination using biomechanical testing in patients with at least ten months of follow-up. Materials and Methods: This cross-sectional comparative cohort study involves patients with ACLR. Inclusion criteria were adult patients who underwent ACLR within the last 3 years, with the same surgical technique performed by a single operator. Patients underwent anamnestic and clinical evaluation and completed Lysholm and KOOS questionnaires. Biomechanical tests included a Unilateral Drop Jump, a Countermovement Jump with knee rotation, and a five-repetition Sit-To-Stand. Force platforms, a camera, and surface electromyography were used to assess biomechanical stability and joint function. Results: This study included 18 subjects, 5 with ACLR and ALLR, and 13 with ACLR alone. The groups showed no significant differences in the KOOS and Lysholm scales and clinical outcomes. Muscle trophism reduction compared to the contralateral limb was noted in both groups. Biomechanical evaluations showed no difference in Quadriceps muscle activity during the landing phase of the Drop Jump. However, the ACL-ALL group exhibited fewer spikes and fewer knee joint angular excursions during ground impact stabilization. In the 5-STS task, a significant difference was observed in the vertical force peak. Differences in muscle activity during foot rotation and force components during the jumping phase were noted in the Countermovement Jump. Conclusions: ACLR combined with ALLR shows similar perceived joint function but improved biomechanical joint stability. Further studies with larger samples and longer follow-ups are needed for validation. Full article

The aim of this study was to investigate associations and differences between dynamic strength index (DSI) and multi-directional jumping, linear and curvilinear sprinting, and change of direction (CoD). Highly trained basketball players (n = 44) performed a 20 m linear sprint, 20 m 3-point line (curvilinear) sprint, countermovement jump (CMJ), drop jump (DJ), bilateral horizontal jump, unilateral horizontal jump, lateral jump, basketball-specific lateral jump and isometric mid-thigh pull (IMTP). The results showed weak to moderate associations between IMTP performance and horizontal jump, lateral jump and curvilinear sprint (r = −0.33–0.41; p < 0.05). No correlations were found between CMJ peak force and performance variables, while weak correlations were observed between DSI and unilateral horizontal jump (r = −0.36; p < 0.05), lateral jumps, linear sprint and CoD deficit (r = −0.37, −0.38; p < 0.05), showing that lower magnitude of DSI is associated with better performance in those tests. Additional analysis revealed that the low DSI subgroup had the highest IMTP peak force, while the high DSI subgroup had the highest CMJ peak force. The low DSI group showed better performance in vertical, horizontal and lateral jumps, while no significant differences were observed in DJ and curvilinear sprint performance compared to other groups. The findings indicate that athletes with lower DSI values exhibit superior physical performance, suggesting that a strength-oriented training approach may be beneficial for basketball players. Due to the ballistic nature of basketball, more maximal strength training is required to optimize the DSI ratio in basketball players. Additional studies are needed to determine the precise benchmarks for navigating training based on DSI values. Full article

The aim of this study was to assess and compare performance and movement variability (MV) in both bilateral and unilateral vertical drop jumps (DVJs) under conditions involving the incorporation or exclusion of ball catching. Twelve amateur basketball players were recruited for participation in the study (seven females and five males). Participants performed three jumps in each of the six conditions analyzed in randomized order: bilateral DVJ without (BNB) and with ball (BB); unilateral DVJ right leg without (RNB) and with ball (RB); and unilateral DVJ left leg without (LNB) and with ball (LB). MV and DVJ performance parameters were analyzed with an accelerometer and a force platform. MV was quantified using the sample entropy (sample entropy; SampEn) derived from the acceleration of the lower back. Differences between the different DVJ conditions were determined with the Wilcoxon test, with a significance level set at p < 0.05. The comparisons were also assessed via standardized mean differences (Cohen’s d). No significant differences were observed in jump height, contact time and reactive strength index between conditions. However, the RB condition reported higher MV compared to RNB (effect size = 0.79; p = 0.016). Similarly, LNB showed greater MV compared to RNB (effect size = −0.62; p = 0.042). The inclusion of the ball in the DVJ increased the MV in the bilateral condition and in the right leg, but not in the unilateral condition with the left leg. The asymmetry between legs (right vs. left) in MV values in NOBALL conditions was higher (≈15%) compared to the BALL condition (≈5%). Full article

Both weak muscle strength and impaired neuromuscular control has previous been suggested as risk factors for future traumatic knee injury. However, data on the relationship between these two factors are scarce. Thus, the aim of this study was to investigate the relationship and influence of the one repetition maximum (1RM) barbell squat strength on dynamic knee valgus in elite female and male handball players. In this cross-sectional study 22 elite handball players (7 females) were included. A unilateral drop jump (VDJ) test was used for the assessment of frontal plane dynamic knee valgus. Players also performed a one repetition maximum (1RM) barbell squat test, expressed relative to bodyweight (r1RM), to assess maximal strength, which were dichotomized to analyze ‘weak’ versus ‘strong’ players according to median. Correlations were noted between r1RM in squat and knee valgus angle for both the non-dominant (r = −0.54; p = 0.009) and dominant leg (r = −0.46, p = 0.03). The odds of knee valgus were eight times higher, for the dominant leg, in the weak group compared to the strong group (p = 0.03) and 27 times higher, for the non-dominant leg (p = 0.002). The outcome of the present study suggests that maximum squat strength plays an important role when it comes to neuromuscular control of the knee, and that weak handball players are at higher risk of knee valgus compared to strong players during jumping activity. Full article

Futsal is one of the most harmful sports due to its great physical demands. The asymmetries have been proposed as one of the most important risk factors of suffering an injury. However, no study has analysed the relationship between neuromuscular assessment and its implication on the likelihood of suffering injuries comparing male and female players. The purpose of the study was to analyse the physical fitness differences between elite futsal players (both male and female) who suffered an injury in the following four months after being evaluated with those who did not suffer the injuries. Twenty-six and twenty-two male and female elite futsal players were recruited from four different teams and underwent an evaluation of different neuromuscular assessments (isometric hip abduction and adduction peak torque, flexion-rotation trunk test, hop test, countermovement jump (CMJ), drop vertical jump (DVJ), leg stiffness, 15 m sprint, Y-balance test, and Illinois test) that have been considered potential sport-related injury risk factors during the pre-season. Statistical analysis only showed differences between injured and non-injured players in isometric hip adduction strength and unilateral ratio for the non-dominant leg (p < 0.05). Neuromuscular performance scores showed significant differences (p < 0.001) between male and female futsal players in several variables (hip abduction non-dominant leg, hops, CMJ, DVJ, leg stiffness, sprint, and Illinois test) but not in ratio or asymmetry. Isometric hip adduction and abduction–adduction unilateral ratio deficits for the non-dominant leg might be an important factor toward suffering an injury. Male and female futsal players showed different neuromuscular performances and consequently different training programs should be implemented for them. Full article

The reactive strength index (RSI) is used to assess reactive strength in the lower limbs. Since previous studies have mostly focused on vertical RSI (derived from drop jumps), we investigated the RSI across eight consecutive unilateral horizontal hops and its associations with sprint performance. A sample of 104 male kinesiology students (age: 19.2 ± 1.1 years) performed unilateral hops and 100 m sprints with split times recorded. RSI was determined as the ratio between contact time and subsequent flight time for each hop. On a group level, the horizontal RSI was statistically significantly (p < 0.001; η_p² = 0.49) and increased from hop 1 (1.04 ± 0.17) to hop 5 (1.41 ± 0.22), but then plateaued (1.43–1.44) for hops 6–8. However, on an individual level, variations in RSI were present all the way to the last hop. All sprint split times were in small-to-moderate correlation with RSI variables (r = 0.25–0.40), implying that individuals with higher hopping RSI presented with shorter sprint times. Future studies should expand the research on the relationship between horizontal hopping RSI and sports performance, and examine if unilateral RSI tests can provide practitioners with valuable information when performed alongside more common vertical RSI tests. Full article