Delayed ankle muscle reaction time in female amateur footballers after the first 15 min of a simulated prolonged football protocol

Establishing a Reference Database for Select Clinical Measures in National Basketball Association Players

BACKGROUND

Musculoskeletal injuries are prevalent in the NBA and are associated with a significant number of games missed. There is a lack of reference data for clinical measures in NBA players, making it difficult for sports medicine professionals to set goals and develop programs.

HYPOTHESIS

Values for clinical measures in NBA players will differ from those of the general population but will not differ between dominant (D) and nondominant (ND) limbs.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Clinical measures were taken on 325 players invited to NBA training camp (2008-2022). Measures included range of motion for great toe extension, hip rotation, weightbearing ankle dorsiflexion, flexibility, arch height (AH) indices, and tibial varum.

RESULTS

Clinical values for NBA players differ from reference norms of the general population. Results for NBA players include great toe extension (D, 40.4°; ND, 39.3°), 90/90 hamstring (D, 41.5°; ND, 40.9°), hip internal rotation (D, 29.0°; ND, 28.8°), hip external rotation (D, 29.7°; ND, 30.9°), total hip rotation (D, 60.2°; ND, 60.4°), Ely (D, 109.9°; ND, 108.8°), AH difference (D, 0.5 mm; ND, 0.5 mm), AH index (D, 0.310; ND, 0.307), arch stiffness (D, 0.024; ND, 0.024), arch rigidity (D, 0.924; ND, 0.925), tibial varum (D, 4.6°; ND, 4.5°), and weightbearing ankle dorsiflexion (D, 35.4°; ND, 35.6°). Descriptive statistics are presented; 2-tailed paired t tests show that, whereas most measures demonstrated differences between sides, the results were not statistically significant.

CONCLUSION

Clinical measures of NBA players differ from those reported for the general population and athletes of other sports although there were no statistically significant differences between D and ND limbs.

CLINICAL RELEVANCE

Establishing a reference database may help clinicians develop more sensitive and more effective preseason and return-to-play screening processes, aiding the management of player orthopaedic care and reducing injury risk.

Influence of a football match on landing biomechanics and jump performance in female football players

This study aimed to assess the acute effect of a competitive football match on jump performance and kinematic parameters during jump landing in semiprofessional female football players. Twenty-two semiprofessional players (20 ± 3 years) underwent a drop jump task for a posterior video analysis of the landing phase. These measurements were obtained at (1) baseline, (2) after, and (3) 48 h after a competitive football match. A one-way ANOVA with repeated measures was employed to detect differences over the time. There was a main effect of time for maximal knee flexion angle during drop landing (p = 0.001). In comparison with baseline, maximal knee flexion angle was reduced immediately post-match and was still reduced 48 h after the match (63.4 ± 8.6 vs 57.0 ± 11.7 vs 48.9 ± 19.1, p ≤ 0.038). There was also a main effect of time for drop jump height (p < 0.001). Drop jump height was reduced immediately post-match and remained low 48 h after the match in comparison with baseline (27.3 ± 3.6 vs 24.5 ± 2.8 ~ 25.5 ± 3.0 cm, p ≤ 0.002). There was a main effect of time on hip flexion angle during landing (p = 0.001), but the pairwise comparison revealed that this variable was not affected immediately post-match but was lower 48 h after the match than at baseline (50.1 ± 10.1 ~ 50.8 ± 13.2 vs 38.1 ± 17.8 °, p ≤ 0.005). A competitive football match worsened jump performance and several landing biomechanical parameters in female football players, which were still decreased in comparison with baseline even 48 h after the match.

Characteristics of Cognitive Abilities among Youths Practicing Football

The aim of the study was to assess selected cognitive abilities depending on age, anthropometric parametres, physical fitness and technical skills in the group of young players training football. The study covered a group of 258 young players practicing football (age: 12.1± 2.03), who were divided into 5 age categories (8–9 years old, 10–11 years old, 12–13 years old, 14–15 years old, 16–17 years old). Selected cognitive abilities include: simple reaction time (SIRT), complex reaction time (CHORT), hand-eye coordination (HECOR) and spatial orientation (SPANT). Studies were performed using Test2Drive computer tests. In addition, the level of physical fitness was measured using: The standing long jump, 30 m sprint, 20 m shuttle run test (without and with the ball) and slalom (without and with the ball). The analysis showed a statistically significant relationship between age and cognitive abilities. There was also a statistically significant correlation between fitness tests and reaction time in individual cognitive tests. There were no statistically significant relationships between technical skills and cognitive abilities. The study confirms that age and physical fitness affect the level of cognitive abilities.

Delayed peroneal muscle reaction time in male amateur footballers during a simulated prolonged football protocol

Peroneal muscle fatigue could result in ankle inversion sprain injuries. This study investigated the peroneal muscle reaction time during a simulated prolonged football protocol. Nine male footballers completed a 105-minute simulated prolonged football protocol. The peroneal muscle reaction time to an ankle inversion perturbation was measured every 15 minutes by a surface electromyography system sampling at 1000 Hz. One-way repeated ANOVA with post-hoc paired t-test showed a steady upward trend starting from 48.9 ms at baseline to 57.1 ms at the end of the first half, followed by a recovery back to 50.9 ms at the start of the second half and a further delay in the last 30 minutes to 60.2 ms at the end of the protocol. Delayed peroneal muscle reaction was found after 30 minutes of the first half and 15 minutes of the second half of a football match. The risk of ankle sprain could increase in the latter minutes in each half protocol. Thus, prevention injury training strategies should focus on these specific durations in football matches.

Peroneal reaction time delayed but dynamic single-legged stability retained in collegiate footballers during a simulated prolonged football protocol

Delayed peroneal reaction time and impaired single-legged dynamic stability were risk factors of lateral ankle sprain (LAS), yet no study explored the change of them during a football match. The aim is to explore the change of peroneal reaction time and single-legged dynamic stability during a football simulation protocol. Twelve collegiate football players voluntarily completed a 105-min football match simulation protocol in which peroneal reaction time, root-mean-square of mediolateral ground reaction force in first 0.4 s (RMS ML 0.4), and the mean mediolateral ground reaction force in the late stage (late dynamic MLGRF), were measured for both legs at 15-min intervals during the protocol. Peroneal reaction time was tested using an electromyography (EMG) system. The ground reaction force variables were measured from GRF data after a single-legged drop-jump landing. Repeated measures one-way MANOVA was conducted to evaluate variables over time and leg dominance. Statistical significance was set at p < 0.05 level. Peroneal reaction time significantly increased for both legs at 45 minutes and after 60 minutes. RMS ML 0.4 of both legs and late dynamic MLGRF for dominant leg remained unchanged throughout the protocol and late dynamic MLGRF for non-dominant leg significantly reduced at the 90th minute.