Restrictions in Ankle Dorsiflexion Range of Motion Alter Landing Kinematics But Not Movement Strategy When Fatigued

Investigating the effects of previous injury on subsequent training loads, physical fitness, and injuries in youth female basketball players

Background

Previous studies have shown that athletes accustomed to higher chronic workloads are less susceptible to injury than those exposed to lower chronic workloads. However, few studies have evaluated whether previous injury influences them. Therefore, this study investigated the impact of previous injuries on subsequent training loads, physical fitness, and injury rates in female youth basketball players.

Methods

Training load, physical fitness, and injuries of 18 young female basketball players (age 16.8 ± 1.4 years) were monitored. Previous injury status was clustered using the K-means clustering algorithm to separate players into high-risk and low-risk groups. Linear mixed models were used to analyze the effects of previous injury status on subsequent training load and physical fitness. Meanwhile, the differences between the players' injury groups were analyzed.

Results

Previous injury status can significantly impact a player's subsequent training loads, including acute loads, chronic loads, skill-based training loads, training monotony, and training strain (all p < 0.05). The two groups had no significant differences in physical fitness (all p > 0.05). Furthermore, the incidence of non-contact injuries was significantly higher in the high-risk group than low-risk group, which would result in more training time lost (all p < 0.05).

Conclusion

This study identified the impact of previous injury status on subsequent training load, physical fitness, and injuries in youth female basketball players. These findings provide valuable insight for coaches to optimize training loads according to previous injury status, aiming to minimize the likelihood of subsequent injuries.

Effects of flossing technique on ankle mobility and vertical jump performance

CONTEXT

Flossing may report benefits on range of motion. However, it's unknown whether flossing using pneumatic tourniquets may influence performance in bilateral countermovement jumping tests.

OBJECTIVE

To analyze the acute effects induced by a flossing protocol with a pneumatic tourniquet placed at the intermalleolar level on jumping ability in basketball players.

STUDY DESIGN

cross-sectional study.

METHODS

54 basketball players (mean (SD) 17.16 (1.27) years; 22.23 (1.99) kg/m2) from a professional club were recruited. After a familiarization phase, a pressurized cuff (continuous pressure at 180 mmHg) was placed at the intermalleolar level for 2 min performing plantar and dorsal flexion movements without load. The Leg Motion test and the Countermovement jump were used to measure ankle dorsiflexion and vertical jump height.

RESULTS

After the intervention, a significant ankle dorsiflexion improvement was observed in the left leg in males (12.48 (5.08) vs. 13.44 (5.23) cm, p < 0.05) and in both ankles in females (right: 9.59 (3.29) vs. 10.74 (3.34) cm, p < 0.05; left: 9.91 (2.77) vs. 10.96 (2.57) cm, p < 0.05). However, the intervention showed no significant difference in bilateral jumping ability in neither group (p > 0.05).

CONCLUSIONS

The application of intermalleolar flossing using pneumatic tourniquet in elite basketball players did not interfere in jumping ability, and it may improve ankle range of motion. These findings may help clinicians make decisions in practice.

The effects of fatigue on the relationship between ankle angle at initial contact and the knee and hip joints in landing: Assessing the risk of ACL injury

BACKGROUND

Anterior cruciate ligament (ACL) injuries may correlate with lower limb angles and biomechanical factors in both dominant and non-dominant legs at initial contact (IC) post-landing. This study aims to investigate the correlation between ankle angles in three axes at IC and knee and hip joint angles during post-spike landings in professional volleyball players, both pre- and post-fatigue induction.

RESEARCH QUESTION

To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike?

METHODS

Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson's correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles.

RESULTS

The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint's positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80).

CONCLUSION

Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.

Age-Related Changes in Landing Mechanics in Elite Male Youth Soccer Players: A Longitudinal Study

The aim of this longitudinal observational study was to examine the age differences in jump landing kinematics in 13–17-year-old male soccer players. Landing technique was evaluated in three consecutive seasons in U14 (n = 15) and the U16 (n = 10) competition age groups using the Landing Error Scoring System (LESS). For the LESS, ANOVA revealed no significant interaction effect (p = 0.81, η2 = 0.009) or main effect for groups (p = 0.15, η2 = 0.086), but a significant year effect was observed (p < 0.001, η2 = 0.265). The LESS score in the U14 group decreased significantly in the second year (5.7 ± 1.9, p = 0.006, d = 0.84) and in the third year (5.9 ± 2.0, p = 0.020, d = 0.70) compared to the first year (7.1 ± 1.7). The LESS score in the U16 group decreased significantly in the second year (5.1 ± 0.9 points, p = 0.034, d = 0.77) and in the third year (4.9 ± 1.4, p = 0.013, d = 0.92) compared to the first year (6.4 ± 1.2). This trend was supported by the results of the separate assessment of the sagittal plane joint displacement. These findings support previous limited findings from cross-sectional studies, which point to improved landing mechanics during maturation. However, the LESS scores in both groups indicate that players who were around and/or post-peak height velocity during the observed periods may be considered “at-risk”, and suggest that preventive training programs should be introduced at earlier stages of players’ development.