Impact of specialized fatigue and backhand smash on the ankle biomechanics of female badminton players

During fatigued conditions, badminton players may experience adverse effects on their ankle joints during smash landings. In addition, the risk of ankle injury may vary with different landing strategies. This study aimed to investigate the influence of sport-specific fatigue factors and two backhand smash actions on ankle biomechanical indices. Thirteen female badminton players (age: 21.2 ± 1.9 years; height: 167.1 ± 4.1 cm; weight: 57.3 ± 5.1 kg; BMI: 20.54 ± 1.57 kg/m2) participated in this study. An 8-camera Vicon motion capture system and three Kistler force platforms were used to collect kinematic and kinetic data before and after fatigue for backhand rear-court jump smash (BRJS) and backhand lateral jump smash (BLJS). A 2 × 2 repeated measures analysis of variance was employed to analyze the effects of these smash landing actions and fatigue factors on ankle biomechanical parameters. Fatigue significantly affected the ankle-joint plantarflexion and inversion angles at the initial contact (IC) phase (p < 0.05), with both angles increasing substantially post-fatigue. From a kinetic perspective, fatigue considerably influenced the peak plantarflexion and peak inversion moments at the ankle joint, which resulted in a decrease the former and an increase in the latter after fatigue. The two smash landing actions demonstrated different landing strategies, and significant main effects were observed on the ankle plantarflexion angle, inversion angle, peak dorsiflexion/plantarflexion moment, peak inversion/eversion moment, and peak internal rotation moment (p < 0.05). The BLJS landing had a much greater landing inversion angle, peak inversion moment, and peak internal rotation moment compared with BRJS landing. The interaction effects of fatigue and smash actions significantly affected the muscle force of the peroneus longus (PL), with a more pronounced decrease in the force of the PL muscle post-fatigue in the BLJS action(post-hoc < 0.05). This study demonstrated that fatigue and smash actions, specifically BRJS and BLJS, significantly affect ankle biomechanical parameters. After fatigue, both actions showed a notable increase in IC plantarflexion and inversion angles and peak inversion moments, which may elevate the risk of lateral ankle sprains. Compared with BRJS, BLJS poses a higher risk of lateral ankle sprains after fatigue.

A Systematic Review on the Effectiveness of Eyewear in Reducing the Incidence and Severity of Eye Injuries in Racket Sports

PURPOSE

To assess what eyewear (if any) reduces eye injury incidence and severity in squash, racketball, tennis and badminton.

DESIGN

Systematic review following the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' (PRISMA) and the 'implementing Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science' (PERSiST) guidelines.

METHODS

PubMed, SportDiscus and Web of Science were searched on 22nd February 2023. All study types except reviews were eligible. Studies had to report the type of eyewear worn (if any) with a form of eye injury incidence and severity.

RESULTS

364 papers were initially retrieved and after the screening process 29 remained. A subgroup analysis was carried out on studies that had a sample size of five or above, were not only looking at a particular type of eye injury and that had sufficient data to allow the percentage of eye injuries that occurred when no eyewear was worn to be calculated. From this analysis, the median percentage of eye injuries that occurred when no eyewear was worn was found to be 93%. Some of these injuries were serious and required complex treatment. Prescription lenses, contact lenses and industrial eyewear made some injuries more severe. In squash and racketball, lensless eye guards were ineffective as the ball could deform on impact, still making contact with the eye. Only eyewear compliant with updated ASTM (or similar) standards was associated with no eye injuries and so provided adequate protection in all four sports.

CONCLUSIONS

Although this systematic review only summarizes evidence on injuries requiring hospital treatment, it is recommended that national governing bodies and key decision makers within squash, racketball, tennis and badminton examine the evidence presented and consider extending existing rules or implementing new recommendations and policies on protective eyewear use to reduce eye injury incidence and severity in their sport.

Better position for the wearable sensor to monitor badminton sport training loads

This study purposed to identify the better accelerometer location for monitoring badminton sports training load by investigating the correlation between internal (HR, training impulse [TRIMP]) training load and external (acceleration, player load [PL]) training loads measured from 5 different body locations. Twelve college-level badminton athletes wore a HR transmitter belt and five accelerometers fixed on both hands, legs, and lower back while performing continuous three-minute training of four badminton skills including backhand serve (BS), net shot (NS), footwork training (FT), and jump smash (JS). Results showed PL at the five locations were significantly related to TRIMP (r = 0.570-0.843, p < 0.05), in which PL at lower back has highest Pearson (r = 0.843) and partial (r = 0.366) correlated to TRIMP (p < 0.05). Base on the stepwise multiple regression, PL at lower back and racket hand explained 88% of the variance of TRIMP (R2 = 0.879). In conclusion, lower back is an idea location for accelerometer to monitor overall external training load in badminton if considering one accelerometer location, while combining PL at the lower back and racket hand can predict 88% of the variation of the internal training load.

Effects of plyometric training on skill-related physical fitness in badminton players: A systematic review and meta-analysis

Skill-related physical fitness significantly correlates with sports performance. Plyometric training (PT) is an effective method for improving physical fitness in athletes. However, its impact on skill-related physical fitness in badminton players remains uncertain. Therefore, this systematic review and meta-analysis aimed to evaluate the effectiveness of PT on skill-related physical fitness in badminton players. Five electronic databases (Web of Science, PubMed, SCOPUS, MEDLINE, and SPORTSDiscus) were searched until February 2024. A PICOS approach was used to identify inclusion criteria, (1) healthy badminton players, (2) a PT program, (3) an active control group, (4) a measure of skill-related physical fitness before and after PT, and (5) randomized controlled studies. The PEDro scale was used to assess the methodological quality of PT studies, while the level of evidence certainty was determined through the GRADE framework. The calculation of effect sizes (ESs) was based on mean values and standard deviations, and heterogeneity was measured with the I2 statistic. The extended Egger's test was employed to check for publication bias. Eleven studies comprising 445 badminton players were eligible for inclusion. The analysis revealed significant small-to-moderate effects of PT on power (ES = 0.60, p < 0.001), agility (ES = 0.96, p < 0.001), speed (ES = 0.63, p = 0.001), and balance (ES = 0.89; p = 0.013). However, no significant effect was observed for reaction time (ES = 0.56; p = 0.189). The certainty of evidence for outcomes was graded as either low or very low. In conclusion, our findings demonstrate that PT improved power, agility, speed, and balance, but not reaction time in badminton players. However, the small number of studies and the very low to low certainty evidence mean that these results need to be interpreted with caution.

volleyball female players?

BACKGROUND

Changing from a static to a dynamic balance condition could affect the performance of a cognitive task such as mental rotation. Thus, the main goal of this study is to investigate aspects of visual-spatial cognition between two non-contact sports (i.e., badminton and volleyball) in different upright conditions (i.e., standing position, frontal balance, and sagittal balance).

METHODS

Thirty-five volunteer female sports and physical education students, fourteen specialists in badminton and twenty-one specialists in volleyball agreed to participate in this study. Each of the assessments was a 3D cube mental rotation task with and/or without balance exercises (i.e., frontal and/or sagittal balance) on a wobble board. Five stimuli were used in the mental rotation task (i.e., 45°, 135°, 180°, 225° and 315° for objected-based cube condition with egocentric transformation) which included pairs of standard and comparison images.

RESULTS

The findings indicate that there was a notable decrease (p < 0.001; d = 1.745) in response time in both dynamic balance conditions (i.e., frontal and sagittal balance) compared to standing position condition. In addition, results revealed significant interaction between balance conditions (i.e., frontal and/or sagittal balance) and groups (i.e., badminton and volleyball) in the response time at 225° angle and in the error percentage.

CONCLUSIONS

In sum, dynamic balance is also an activity that involves mental manipulation of objects in 3D space, which can enhance badminton and volleyball female players' ability to rotate 3D cube stimuli.

Influence of Torsional Stiffness in Badminton Footwear on Lower Limb Biomechanics

Torsional stiffness of athletic footwear plays a crucial role in preventing injury and improving sports performance. Yet, there is a lack of research focused on the biomechanical effect of torsional stiffness in badminton shoes. This study aimed to comprehensively investigate the influence of three different levels of torsional stiffness in badminton shoes on biomechanical characteristics, sports performance, and injury risk in badminton players. Fifteen male players, aged 22.8 ± 1.96 years, participated in the study, performing badminton-specific tasks, including forehand clear stroke [left foot (FCL) and right foot (FCR)], 45-degree sidestep cutting (45C), and consecutive vertical jumps (CVJ). The tasks were conducted wearing badminton shoes of torsional stiffness measured with Shore D hardness 50, 60, and 70 (referred to as 50D, 60D, and 70D, respectively). The primary biomechanical parameters included ankle, knee, and MTP joint kinematics, ankle and knee joint moments, peak ground reaction forces, joint range of motion (ROM), and stance time. A one-way repeated measures ANOVA was employed for normally distributed data and Friedman tests for non-normally distributed data. The 70D shoe exhibited the highest ankle dorsiflexion and lowest ankle inversion peak angles during 45C task. The 60D shoe showed significantly lower knee abduction angle and coronal motions compared to the 50D and 70D shoes. Increased torsional stiffness reduced stance time in the FCR task. No significant differences were observed in anterior-posterior and medial-lateral ground reaction forces (GRF). However, the 70D shoe demonstrated higher vertical GRF than the 50D shoe while performing the FCR task, particularly during 70% - 75% of stance. Findings from this study revealed the significant role of torsional stiffness in reducing injury risk and optimizing performance during badminton tasks, indicating that shoes with an intermediate level of stiffness (60D) could provide a beneficial balance between flexibility and stability. These findings may provide practical references in guiding future badminton shoe research and development. Further research is necessary to explore the long-term effects of altering stiffness, considering factors such as athletic levels and foot morphology, to understand of the influence of torsional stiffness on motion biomechanics and injury prevalence in badminton-specific tasks.

Eye injuries in badminton - players' perspective toward the usage of personal protective equipment

OBJECTIVE

We conducted a survey between April to September 2021 to understand the perspective of badminton players on the usage of personal protective equipment to avoid eye injuries.

METHODS

The survey was conducted online. It was disseminated through various social media platforms and via e-mail. The survey was initially shared with university-level badminton players. Both recreational and professional players were included. They were further encouraged to circulate the survey questionnaire among their colleagues.

RESULTS

In total, the survey received 372 responses. After removing possible duplicates and incomplete responses (n = 28), 92.5% (n = 344) of the responses were included in the final analysis. Among the 344 included responses, recreational and professional players accounted for 77.6% (n = 267) and 22.4% (n = 77), respectively. The mean age ± SD of the recreational and professional players were 24.1 ± 6.3 years (range 14-60 years) and 25.7 ± 6.0 years (range 14-61 years), respectively. A significant difference was noted for self-reported eye injuries between recreational and professional players while playing badminton (χ2 value = 5.321, p = 0.02). Among the recreational and professional players, 93.6% (n = 250) and 88.3% (n = 68) did not use protective eyewear while playing badminton. Professional players were at higher risk of eye injuries than recreational players (OR = 2.9, 95% CI = 1.1-7.8).

CONCLUSION

The majority of badminton players in both groups agreed that PPE usage would lower the risk of sustaining eye injuries; however, they are ambiguous about the usage of protective eyewear. In contrast, players with self-reported eye injuries were aware of its impacts and encouraged the usage of PPEs associated with badminton. Further studies are warranted to understand and educate badminton players about the causes and impacts of eye injuries in badminton.

Acute injuries in Badminton from 10 to 66 years of age: an epidemiological study of 140 cases among all types of practice

PURPOSE

The main objective of this retrospective study was to establish an epidemiological overview of patients admitted to an Emergency department specialized in musculo-skeletal trauma for acute lesions related to Badminton practice in the period from January 1st 2010 to January 1st 2015.

METHODS

There were 135 patients with 140 admissions and 146 total number of injuries. There were 67 females (48%) and 73 males (52%). The mean age was 28 ± 13.8 years, ranging 10-66 years. 91 patients (65%) could be contacted by telephone to fill a questionnaire aimed at completing the information provided by the medical records.

RESULTS

129 lesions (88.3%) were located to the lower limbs, 16 (11%) to the upper limbs, and one (0.7%) at the head. For the whole series, there were 89 sprains (60.9%), 32 tendino-muscular lesions (21.9%), 13 fractures (8.9%), 5 dislocations (3.4%), 3 painful contusions (2.1%), 3 meniscal injuries (2.1%) and one wound (0.7%). In the lower limbs, lateral ankle sprain was the most frequent diagnosis (43.4%), followed successively by rupture of the Achilles tendon (13.9%), tennis leg (8.5%), and mid-foot sprain (6.9%). Of the 146 lesions, 117 (80.1%) received non-operative treatment, 28 (19.1%) received surgical treatment in the operation room, and one simple wound (0.7%) was sutured in the emergency room.

CONCLUSIONS

Lateral ankle sprains followed by tendino-muscular lesions of the calf are by far the most frequent lesions of badminton. Modification of the shoes of badminton players should be considered to decrease the high incidence of ankle injuries.

Longitudinal study on locations of injury among junior high school, high school, and university badminton athletes at Japanese national-level competitions

[Purpose] The aim of study was to examine incidence of injury according to location of injury to develop an injury prevention program for elite badminton players of junior high school, high school, and university. [Participants and Methods] We conducted a prospective longitudinal study, between April 2012 and March 2013, on 133 national-level badminton players attending junior high school, high school, and university. Injury rates in athletes per 1,000 exposures were calculated based on gender and school age for the five most common injury locations, in addition, severity, type and circumstance were investigated. [Results] Injury rates in athletes per 1,000 exposures were the highest in the racket-side (RS) shoulder/clavicle among the female university students (4.35), RS thigh of high school females (2.21), and lumbar spine/lower back of males of all school ages and junior high school females (1.83–1.25). Significantly higher injury rates were noted for the overuse of the lumbar spine/lower back and RS shoulder/clavicle, trauma of the RS thigh and ankle, and injury, when compared with slight injury of the RS ankle. [Conclusion] Injury prevention programs should be developed for RS shoulder/clavicle overuse in university females, RS thigh trauma in high school females, and lumbar spine/lower back in males of all school ages and junior high school females.

Effects of badminton insole design on stress distribution, displacement and bone rotation of ankle joint during single-leg landing: a finite element analysis

Previous research has reported that up to 92% of injuries amongst badminton players consist of lower limb, whereby 35% of foot fractures occurred at the metatarsal bone. In sports, insoles are widely used to increase athletes' performance and prevent many injuries. However, there is still a lack of badminton insole analysis and improvements. Therefore, this study aimed to biomechanically analyse three different insole designs. A validated and converged three-dimensional (3D) finite element model of ankle-foot complex was developed, which consisted of the skin, talus, calcaneus, navicular, three cuneiform, cuboid, five metatarsals and five phalanges. Three existing insoles from the market, (1) Yonex Active Pro Truactive, (2) Victor VT-XD 8 and (3) Li-Ning L6200LA, were scanned using a 3D scanner. For the analysis, single-leg landing was simulated. On the superior surface of the skin, 2.57 times of the bodyweight was axially applied, and the inferior surface of the outsole was fixed. The results showed that Insole 3 was the most optimum design to reduce peak stress on the metatarsals (3.807 MPa). In conclusion, the optimum design of Insole 3, based on the finite element analysis, could be a justification of athletes' choices to prevent injury and other complications.

Risk Prediction of Injury Among Recreational Badminton Players in India

BACKGROUND/PURPOSE

Since badminton has emerged as a frequently played non-contact recreational sport in India, it is essential to document the injury patterns and incidence. However, there is no existing literature on this topic among Indian players.

MATERIALS AND METHODS

A web-based questionnaire was circulated among recreational badminton players across North India, enquiring about demographic details, injury characteristics, and factors associated with an injury like BMI, warm-up practice, and physical training.

RESULTS

Data of 237 eligible participants revealed an injury incidence rate of 57.1%. The ankle and dominant-side shoulder were the most common anatomical regions affected. The most common injury types were ligament sprain and muscle/tendon strain. Factors like age, frequency, duration of play, type of footwear, BMI, prior warm-up, court surface, and physical training were significantly associated with injury incidence on univariate logistic regression analysis. On multivariate logistic regression analysis, we found male gender, a lack of prior warm-up, inadequate physical training, and age group between 26 and 30 years to be four independent risk factors for injury.

CONCLUSION

The recreational badminton player of India had a relatively higher incidence of injury compared with the limited published data from other countries. Modifiable factors like a proper warm-up before the game, regular physical fitness training, and injury awareness programs can reduce the injury rates.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00663-y.

Training and injuries among world elite junior badminton players - Identifying the problems

Background

The game of badminton has evolved since the early injury epidemiology studies. Since there is no published literature on injuries in elite junior badminton players from an international cohort, this study provides an updated reference of injuries in this population to inform future injury prevention strategies. The objective of this study was to report injury prevalence and training hours in elite junior badminton players participating at the World Junior Championships in 2018.

Methods

A questionnaire was used to collect data and was available in English, French, Spanish, Korean, Japanese or Chinese. It was designed to collect information including basic demographics, hours of training and competition, number of tournaments per year, current and previous injuries characterized by anatomical region, diagnosis, treatment and injury duration. The questions were focused on previous significant injuries lasting a minimum of 30 days and current musculoskeletal symptoms.

Results

One hundred and sixty-four of 436 players with a mean age of 17.1 years (SD ± 0.8) filled in the questionnaire. Participants represented North and South America, Europe, Asia, Africa and The Pacific's including the top 10 performing nations, providing a good overall representation of tournament participants. A total of 104 significant injuries (median duration of 90 days) with disruption of full training or competition capacity were reported. Seventy-eight (48%) players reported one or more significant injury. The most common location of significant injury was in the knee, ankle and lower back. Eleven injuries were reported as stress fractures. In 35 cases a player felt lasting limitation from a significant injury and in 37 cases a player felt lasting pain.

Conclusion

Previously in their career almost 50% of the players had sustained a significant injury with a median duration of 90 days. The lower extremities and the lower back were the predominant injured regions. In one third of the injuries a player had lasting limitations or pain. Stress fractures may be a serious underestimated problem in badminton.

Analyze the Differential Rates of Anterior Cruciate Ligament Injuries Between Men and Women by Biomechanical Study of Single-Leg Landing in Badminton

BACKGROUND

In female badminton players, certain landings are associated with injury to the anterior cruciate ligament (ACL). However, the kinematic and kinetic changes of the landing leg and the effects of risky posture on ACL injuries among female vs male badminton players are still unknown. We hypothesized that female players land with a significantly higher knee valgus angle and moment compared to male players during single-leg landings in badminton.

METHODS

Ten male and ten female badminton players were enrolled in this study. In the laboratory, these subjects performed back-stepping to the backhand side with a concurrent overhead stroke, a single-leg landing on the force plate, and a return to the starting position. The kinematic data in the stance phase were normalized ranging from 0% as initial contact to 100% as toe-off; and 0% as initial contact to 100% as maximum knee flexion in the impact phase.

RESULTS

The knee valgus angle in female players was significantly higher in initial contact (5.06° ± 6.83° vs - 5.10° ± 4.30, p = .001) and maximal knee valgus angle (7.58° ± 9.54° vs - 3.93° ± 4.22°, p = .004) compared to male players. The knee valgus moment was significantly higher in male players than female players ( - 0.09 ± 0.12 vs 0.03 ± 0.10 N∙m/kg, p = .032) in initial contact during the impact phase. During landings, female badminton players had lower hip flexion angles, greater knee valgus angles, and greater ankle dorsiflexion angles.

CONCLUSION

Female badminton players presented higher knee valgus angles but smaller knee valgus moments compared with male players during backward single-leg landings. The concomitant kinematic and kinetic changes of the hip, knee, and ankle joints also can play an important role in the higher incidence of ACL injury in female athletes.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00421-6.

non-injured tendons

BACKGROUND

The aim of this study was to describe the differences in structural and mechanical properties between operated and non-injured Achilles tendons in senior badminton players who had had Achilles tendon surgery and had returned to play.

METHODS

Eighteen players (age = 48.9(10.0)years), assigned to the unilateral Achilles tendon rupture group and 177 non-injured players (age = 55.4(9.4)years), assigned to the control group. A Logiq®S8 ultrasound was used to study tendon structure and elastography index values and a Myoton®PRO hand-held myotonometer was used to record the stiffness of the Achilles tendon.

FINDINGS

In Achilles tendon rupture group, operated tendons showed higher values than non-injured ones in thickness (Operated = 9.03(2.67)mm vs. non-injured = 5.88(0.88)mm; P < 0.001), width (Operated = 18.44(3.20)mm vs. non-injured = 16.80(1.97)mm; P = 0.039), cross sectional area (Operated = 140.33(60.29)mm² vs. non-injured = 74.40(17.09)mm²; P < 0.001) and elastography index (Operated = 2.05(1.35)A.U. vs. non-injured = 1.47(0.62)A.U.; P = 0.025). The bilateral differences shown by the Achilles tendon rupture group were greater than the bilateral differences shown by the control group for thickness (P < 0.001), width (P = 0.001), cross sectional area (P < 0.001), tone (P = 0.006) and dynamic stiffness (Achilles tendon rupture group = 10.85(23.90)N∙m^-1. vs. control group = 0.18(18.83)N∙m^-1; P = 0.031).

INTERPRETATION

Surgery on the Achilles tendon and adaptation to the mobilisation and strength training during rehabilitation could provoke structural and mechanical differences compared to the non-injured tendon. Furthermore, the differences between both Achilles tendons in the Achilles tendon rupture group was higher than the asymmetry observed between dominant and non-dominant Achilles tendons in the control group. In addition, the higher logarithmic decrement values showed by non-injured tendons in the Achilles tendon rupture group could be a tendinous injury risk factor.

Penetrating ocular trauma by nail of a badminton feather shuttle cock: A rare case report

Sports-related ocular traumas may be rare, but can have devastating and disabling consequences. The causes of eye-related injuries depend on the type of sports popular in a particular area or country. Badminton is a popular sport played by all age groups and socioeconomic segments and is popular in many parts of the world. It is most popular in South-East Asia, accounting for two-thirds of all ocular sports injury in Malaysia. In India, badminton has become quite popular in recent years. Shuttlecocks in badminton have been shown to be responsible for a high number of outpatient ocular sports-related, mostly blunt injuries. We report an unusual case of penetrating ocular injury due to a feather shuttlecock and its surgical management.

Badminton Injuries in Elite Athletes: A Review of Epidemiology and Biomechanics

Badminton is a popular sport in India and with multiple medal prospects will be closely followed at the Tokyo 2020 Olympics. Considered the fastest of the racquet sports, players require aerobic stamina, agility, strength, speed, and precision, besides requiring good motor coordination and complex racquet movements. Injuries in badminton are common despite it not being a contact sport, and include overuse injuries, and acute traumatic events. The game is physically challenging and demands complex repetitive upper and lower extremity movements with constant postural variations and poses a high risk of overuse injuries to both the appendicular and axial musculoskeletal systems. Badminton also necessitates short bursts of movement with sudden sharp changes in direction, which places players at risk of non-contact traumatic injuries to joints and muscle-tendon units. Preventing injuries and decreasing time away from training and competition are critical in an elite badminton player's sporting career. This analytical review identifies the incidence, severity, and profile of badminton injuries in elite players, and discusses the biomechanical basis of these injuries.

Influence of badminton practice on calcaneal bone stiffness and plantar pressure

Objectives: The aim of this study was to analyze the plantar pressures and bone stiffness of the calcaneus in badminton players compare to healthy participants, as well as to detect possible asymmetries and chronic adaptations derived from the prolonged practice of badminton.Methods: Twenty-two badminton players (35.2 ± 13.6 years, 169.4 ± 8.2 cm, 67.6 ± 13.7 kg) and 30 healthy controls (32.2 ± 12.8 years, 170.7 ± 9.5 cm, 66.25 ± 14.84 kg) volunteered to participate in this investigation. A Footwork® Pro pressure platform was used to study plantar pressures and an Achilles® bone scanner was used to record the bone stiffness of the calcaneus. The variables analyzed were plantar surface, percentage of force per area (forefoot and hindfoot), distance between the center of pressure and the projection of the center of mass in standing, and calcaneal bone stiffness.Results: The values of bone stiffness of the calcaneus were higher in badminton players than control group in the dominant lower limb (Badminton = 114.32 ± 18.97 U.A. vs. Control = 102.07 ± 16.36 U.A.; p = 0.019) and non-dominant lower limb (Badminton = 115.12 ± 21.95 U.A. vs Control = 101.37 ± 15.72 U.A.; p = 0.014). Badminton players showed asymmetric values in mean pressure (dominant = 35.41 ± 6.05 Kpa vs. non-dominant = 39.21 ± 6.54 Kpa; p = 0.011) and distance among center of pressure of each foot and center of mass (dominant = 11.28 ± 1.65 cm vs. non-dominant = 10.48 ± 1.63 cm; p = 0.025).Conclusions: The calcaneal stiffness of the badminton players was higher than control group, which places badminton in the category of osteogenic sports. The badminton players showed an asymmetric pattern during the static balance, which may be an indicative of asymmetries derived from the continued practice of badminton.

An exploration of the effect of proprioceptive knee bracing on biomechanics during a badminton lunge to the net, and the implications to injury mechanisms

The aim of this study was to determine changes in knee biomechanics during badminton lunges due to fatigue, lunge strategy and knee bracing. Kinetic and kinematic data were collected from 16 experienced right-handed badminton players. Three factor repeated measures ANOVAs (lunge direction—fatigue—brace) were performed with Least Significant Difference pairwise comparisons. In addition, clinical assessments including; Y-balance test, one leg hop distance and ankle dorsiflexion range of motion were performed pre- and postfatigue. The knee showed significantly greater flexion during the forehand lunge compared to backhand. In contrast, the internal rotation velocity and the knee extension moment were greater during backhand. Knee angular velocity in the sagittal plane, peak knee moment and range of moment in the coronal plane and stance time showed significantly lower values postfatigue. In addition, the peak knee adduction moment showed significantly lower values in the braced condition in both the fatigued and nonfatigues states, and no significant differences were seen for peak vertical force, loading rate, approach velocity, or in any of the clinical assessment scores. There appears to be greater risk factors when performing a backhand lunge to the net compared to a forehand lunge, and proprioceptive bracing appears to reduce the loading at the knee.

Relationship between agility and lower limb muscle strength, targeting university badminton players

[Purpose] Targeting university badminton players, this study investigated the relationship between agility, which is associated with performance in badminton, and lower limb muscle strength, and examined which muscles influence agility. [Subjects and Methods] A total of 23 male university badminton players were evaluated for side-shuffle test scores and lower limb strength. The relationships between agility, lower limb strength, and duration of experience playing badminton were evaluated using a correlation analysis. Moreover, the relationship between agility and lower limb strength was evaluated by partial correlation analysis, adjusting for the effects of experience of each badminton player. [Results] The agility score correlated with hip extension and ankle plantar flexion strength, with adjustment for badminton experience. [Conclusion] This study suggests that hip extension training and improvement in ankle plantar flexion strength may improve agility.

Characteristics of lower limb muscle activity during upper limb elevation in badminton players

[Purpose] To clarify the characteristics of postural control in badminton players by examining their lower-limb muscle activity during upper-limb elevation. [Subjects and Methods] Fourteen badminton players and 14 non-players were studied. The subjects were instructed to perform an upper-limb elevation task in order to measure the activities of the biceps femoris and biceps brachii. [Results] When elevating the dominant hand, the mean biceps femoris integrated electromyogram showed markedly higher values in the player group, for the contralateral compared with the ipsilateral leg. Similarly, when elevating the dominant hand, the difference in the maximum integrated electromyogram response time between the ipsilateral and contralateral legs was significantly smaller in the players compared with non-players. [Conclusion] It may be possible to reduce the time needed to elevate the dominant hand by shifting lower-limb activity from the ipsilateral to the contralateral leg more quickly, while increasing the rate of rise in contralateral leg muscle activity.

Soleus H-reflex modulation during receive stance in badminton players in the receive stance

[Purpose] This study aimed to clarify the characteristics of motor neuron excitability by examining the soleus H-reflex in the ready position adopted immediately before making a return during badminton games. [Subjects] Sixteen individuals with (badminton group) and 16 without (control group) experience of playing badminton were studied. [Methods] Each subject was instructed to take up various stances for returning a shuttlecock to measure the H- and M-waves in the soleus. [Results] The H-wave was significantly decreased when gripping a racket was held in the dominant hand than compared to just standing in the badminton group. In contrast, in the control group, no significant differences were observed between when standing and the other stances. [Conclusion] Based on these results, the excitability of spinal motor neurons may have been reduced (H-wave suppression) by badminton training to increase the instantaneous force (power training).

A dynamical system perspective to understanding badminton singles game play

By altering the task constraints of cooperative and competitive game contexts in badminton, insights can be obtained from a dynamical systems perspective to investigate the underlying processes that results in either a gradual shift or transition of playing patterns. Positional data of three pairs of skilled female badminton players (average age 20.5±1.38years) were captured and analyzed. Local correlation coefficient, which provides information on the relationship of players' displacement data, between each pair of players was computed for angle and distance from base position. Speed scalar product was in turn established from speed vectors of the players. The results revealed two patterns of playing behaviors (i.e., in-phase and anti-phase patterns) for movement displacement. Anti-phase relation was the dominant coupling pattern for speed scalar relationships among the pairs of players. Speed scalar product, as a collective variable, was different between cooperative and competitive plays with a greater variability in amplitude seen in competitive plays leading to a winning point. The findings from this study provide evidence for increasing stroke variability to perturb existing stable patterns of play and highlights the potential for speed scalar product to be a collective variable to distinguish different patterns of play (e.g., cooperative and competitive).

Comparison of Blue-Yellow Opponent Color Contrast Sensitivity Function between Female Badminton Players and Non-athletes

Purpose

To compare the chromatic contrast sensitivity function (CSF) for the blue-yellow opponent channel (BYOC) between female badminton players and non-athlete controls.

Methods

We recruited 40 young females (18-25 years old) who played badminton for at least 5 consecutive years as the test group, and 30 age-matched female controls who had no history of regular physical activity. The Pattern Generator™ system was used to test the CSF for the BYOC which was performed at three spatial frequencies (SFs) of 2 cycles per degree (cpd), 5 cpd, and 25 cpd.

Results

Comparison of BYOC thresholds showed significantly better results in the test group for all three SFs (P<0.001). Band pass shift (better CSF in the middle SF) was seen in the test group. The control group had low pass (better CSF in the low SF). Ocular motility (heterophoria, fusional convergence and divergence at far and near distances, and near point of convergence) was better in the test group, but the inter-group difference was not significant.

Conclusions

The BYOC threshold results for badminton players indicated a better visual performance which may be a result of enhanced performance of the parallel processing of the parvocellular and magnocellular systems. This may be inherent and/or acquired in badminton players. In addition, badminton players appear to have developed sensory-motor programmed activities. Testing the CSF for BYOC may be useful for athlete selection in different levels and/or used as a criterion for screening players in the field of badminton.

Bilateral ground reaction forces and joint moments for lateral sidestepping and crossover stepping tasks

Racquet sports have high levels of joint injuries suggesting the joint loads during play may be excessive. Sports such as badminton employ lateral sidestepping (SS) and crossover stepping (XS) movements which so far have not been described in terms of biomechanics. This study examined bilateral ground reaction forces and three dimensional joint kinetics for both these gaits in order to determine the demands of the movements on the leading and trailing limb and predict the contribution of these movements to the occurrence of overuse injury of the lower limbs. A force platform and motion-analysis system were used to record ground reaction forces and track marker trajectories of 9 experienced male badminton players performing lateral SS, XS and forward running tasks at a controlled speed of 3 m·s(-1) using their normal technique. Ground reaction force and kinetic data for the hip, knee and ankle were analyzed, averaged across the group and the biomechanical variables compared. In all cases the ground reaction forces and joint moments were less than those experienced during moderate running suggesting that in normal play SS and XS gaits do not lead to high forces that could contribute to increased injury risk. Ground reaction forces during SS and XS do not appear to contribute to the development of overuse injury. The distinct roles of the leading and trailing limb, acting as a generator of vertical force and shock absorber respectively, during the SS and XS may however contribute to the development of muscular imbalances which may ultimately contribute to the development of overuse injury. However it is still possible that faulty use of these gaits might lead to high loads and this should be the subject of future work. Key pointsGround reaction forces and joint moments during lateral stepping are smaller in magnitude than those experienced during moderate running.Force exposure in SS and XS gaits in normal play does not appear to contribute to the development of overuse injuryThe leading and trailing limbs perform distinct roles, acting as a generator of vertical force and shock absorber respectively.This distinct contribution may contribute to the development of muscular imbalances which may ultimately contribute to the development of overuse injury.