Comparison of Lower Extremity Alignment among Taekwondo Athletes of Various Subdisciplines.

Background and Objectives: Studies analyzing lower extremity alignment (LEA) LEA among taekwondo subdisciplines athletes are lacking. This study compared LEA in the dominant and nondominant legs intaekwondo athletes. Materials and Methods: Twelve measurements of LEA were analyzed for 157 athletes (63 sparring, 50 demonstration, and 44 poomsae athletes) registered with the Korea Taekwondo Association. LEA was measured in the standing, supine, and prone positions using alignment application, a goniometer, a bubble inclinometer, a height gage, and a palpation meter. Results: The analysis revealed that the dominant leg of poomsae athletes showed greater genu valgum alignment than that of sparring athletes (p < 0.01), whereas the dominant leg of sparring athletes showed greater rearfoot varum alignment than that of demonstration athletes (p < 0.01). Furthermore, the nondominant leg of poomsae athletes showed greater genu valgum alignment than that of sparring and demonstration athletes (p < 0.01), whereas the nondominant leg of sparring athletes showed greater rearfoot varum alignment than that of demonstration athletes (p < 0.01). In addition, demonstration athletes had better forefoot varus alignment than poomsae athletes (p < 0.01). Conclusions: This study revealed that LEA characteristics vary among taekwondo athletes according to their subdiscipline. The results of this study would help in designing training programs tailored to each subdiscipline that would best address their LEA characteristics and help to prevent injuries.

Injury Incidence and Its Characteristics in Korean Youth and Collegiate Taekwondo Sparring Athletes: A Retrospective Study.

This study aimed to identify the incidence of injury and its characteristics in Korean youth and collegiate Taekwondo athletes during 2021 and to provide a suggestion regarding injury incidence. A total of 183 athletes (95 youth and 88 collegiate athletes) who were registered with the Korea Taekwondo Association (KTA) participated. The research was based on the injury questionnaire developed by the International Olympic Committee (IOC). The questionnaire consists of a total of seven items, including four items related to demographic characteristics and three items related to injuries (locations of injury, types of injury, and causes of injury). A frequency analysis was performed to identify the injury characteristics. Additionally, the injury incidence rate (IIR) was calculated based on 1000 athletic exposures (AEs) during 2021. The IIRs for one recent year (2021) showed 4.43/1000 AEs and 3.13/1000 AEs in youth and collegiate Taekwondo athletes, respectively. The frequency analysis showed that finger (youth: 17.3%, collegiate: 14.6%), contusion (youth: 25.3%, collegiate: 23.8%), and contact with other athletes (youth: 57.6%, collegiate: 54.4%) ranked the highest in terms of the locations of injury, types of injury, and causes of injury, respectively. A continuing injury tracking system can play a key role in accumulating big data for identifying risk factors and developing interventions to reduce injury in Taekwondo sparring.

Incidence of Sport Injuries in the Manchester 2019 World Taekwondo Championships: A Prospective Study of 936 Athletes from 145 Countries.

We aimed to describe injury incidence and patterns at the 2019 World Taekwondo Championships (WTC), and to compare them with those of previous WTCs, based on new World Taekwondo (WT) competition rules, medical codes, and the Protector and Scoring System (PSS). This prospective cohort study utilized data obtained through the WT Injury Surveillance System. All athletes with injuries were evaluated by on-site sports medicine specialists, and ultrasonography was used to assess all musculoskeletal injuries. Of 936 athletes, 60 injuries were recorded (6.4 injuries/100 athletes, 95% confidence intervals [CI]: 4.8-8.0), and 4.5% (n = 42) sustained at least one injury. Males had a higher risk of sustaining injuries than females (incidence rate ratio: 1.57; 95% CI: 0.89-2.76). The most common sites, type, and mechanism were lower extremities (n = 26, 43.33%), contusion/hematoma/bruises (n = 33, 55.0%), and contact with another athlete (n = 50, 83.33%). Overall, the injury patterns associated with the mechanism of injury were similar in both the 2019 and 2017 WTCs. Refined WT competition rules and a re-established PSS at the 2019 WTC reduced the overall and severe injury incidence. Our findings can help revise Taekwondo competition rules, enhance protective equipment, optimize on-site venue medical systems, and develop injury prevention projects.

Anterior Cruciate Ligament Reconstructed Patients Who Recovered Normal Postural Control Have Dissimilar Brain Activation Patterns Compared to Healthy Controls.

Postural control, which is a fundamental functional skill, reflects integration and coordination of sensory information. Damaged anterior cruciate ligament (ACL) may alter neural activation patterns in the brain, despite patients' surgical reconstruction (ACLR). However, it is unknown whether ACLR patients with normal postural control have persistent neural adaptation in the brain. Therefore, we explored theta (4-8 Hz) and alpha-2 (10-12 Hz) oscillation bands at the prefrontal, premotor/supplementary motor, primary motor, somatosensory, and primary visual cortices, in which electrocortical activation is highly associated with goal-directed decision-making, preparation of movement, motor output, sensory input, and visual processing, respectively, during first 3 s of a single-leg stance at two different task complexities (stable/unstable) between ACLR patients and healthy controls. We observed that ACLR patients showed similar postural control ability to healthy controls, but dissimilar neural activation patterns in the brain. To conclude, we demonstrated that ACLR patients may rely on more neural sources on movement preparation in conjunction with sensory feedback during the early single-leg stance period relative to healthy controls to maintain postural control. This may be a compensatory protective mechanism to accommodate for the altered sensory inputs from the reconstructed knee and task complexity. Our study elucidates the strategically different brain activity utilized by ACLR patients to sustain postural control.

Acute Effects of Open Kinetic Chain Exercise Versus Those of Closed Kinetic Chain Exercise on Quadriceps Muscle Thickness in Healthy Adults.

This study aimed to compare immediate changes in the thickness of the rectus femoris (RF), vastus intermedius (VI), vastus lateralis (VL), vastus medialis (VM), and vastus medialis oblique (VMO) muscles after open kinetic chain exercise (OKCE) and closed kinetic chain exercise (CKCE) and identify the effect of both exercise types on each quadricep muscle for early rehabilitation to prevent knee joint injury. Twenty-six healthy participants (13 males and 13 females) were randomly divided into the OKCE (n = 13) and CKCE (n = 13) groups. The thickness of their quadriceps muscles was measured using a portable ultrasonic imaging device before and after exercise in the sequence RF, VI, VL, VM, and VMO. A two-way repeated measures analysis of variance was used to compare the thickness of each component of the quadriceps muscles between the two groups. The thickness of the RF, VL, VM, and VMO muscles increased after OKCE, and the thickness of the VI muscle showed the greatest increase with a medium-large effect size (F = 8.52, p = 0.01, and d = 0.53). The thickness of the VI, VL, VM, and VMO muscles increased after CKCE, and the VMO muscle had the largest effect size (F = 11.71, p = 0.00, and d = 1.02). These results indicate that the thickness of the quadriceps muscles can be selectively improved depending on the type of exercise.

Bilateral Comparisons of Quadriceps Thickness after Anterior Cruciate Ligament Reconstruction.

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48-72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb; RCL = Pre-operated (PRE): 19.89 ± 6.91 mm, Post-operated(POST): 16.04 ± 6.13 mm, Healthy limb; HL = PRE: 22.88 ± 6.07, POST: 20.90 ± 5.78 mm, F = 9.325, p = 0.009, η2p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR.

Effects of a 4-Week Short-Foot Exercise Program on Gait Characteristics in Patients With Stage II Posterior Tibial Tendon Dysfunction.

CONTEXT: Clinically, it has been suggested that increased activation of intrinsic foot muscles may alter the demand of extrinsic muscle activity surrounding the ankle joint in patients with stage II posterior tibial tendon dysfunction. However, there is limited empirical evidence supporting this notion. OBJECTIVE: The purpose of this study was to investigate the effects of a 4-week short-foot exercise (SFE) on biomechanical factors in patients with stage II posterior tibial tendon dysfunction. DESIGN: Single-group pretest-posttest. SETTING: University laboratory. PARTICIPANTS: Fifteen subjects (8 males and 7 females) with stage II posterior tibial tendon dysfunction who had pain in posterior tibial tendon, pronated foot deformity (foot posture index ≥+6), and flexible foot deformity (navicular drop ≥10 mm) were voluntarily recruited. INTERVENTION: All subjects completed a 4-week SFE program (15 repetitions × 5 sets/d and 3 d/wk) of 4 stages (standing with feedback, sitting, double-leg, and one-leg standing position). MAIN OUTCOME MEASURES: Ankle joint kinematics and kinetics and tibialis anterior and fibularis longus muscle activation (% maximum voluntary isometric contraction) during gait were measured before and after SFE program. Cohen d effect size (ES [95% confidence intervals]) was calculated. RESULTS: During the first rocker, tibialis anterior activation decreased at peak plantarflexion (ES = 0.75 [0.01 to 1.49]) and inversion (ES = 0.77 [0.03 to 1.51]) angle. During the second rocker, peak dorsiflexion angle (ES = 0.77 [0.03 to 1.51]) and tibialis anterior activation at peak eversion (ES = 1.57 [0.76 to 2.39]) reduced. During the third rocker, the peak abduction angle (ES = 0.80 [0.06 to 1.54]) and tibialis anterior and fibularis longus activation at peak plantarflexion (ES = 1.34 [0.54 to 2.13]; ES = 1.99 [1.11 to 2.86]) and abduction (ES = 1.29 [0.50 to 2.08]; ES = 1.67 [0.84 to 2.50]) decreased. CONCLUSIONS: Our 4-week SFE program may have positive effects on changing muscle activation patterns for tibialis anterior and fibularis longus muscles, although it could not influence their structural deformity and ankle joint moment. It could produce a potential benefit of decreased tibialis posterior activation.

Exercise-induced myokines: a brief review of controversial issues of this decade.

INTRODUCTION: Myokines, known to mediate metabolism, inflammation, and other pathophysiological conditions, have been widely investigated, including myokines induced by exercise. However, among published literature, there is substantial inconsistency in the quantification of exercise-induced myokines. Here, we summarized and compared published data regarding the effects of exercise on commonly studied myokines including apelin, Brain-derived neurotrophic factor (BDNF), Interleukin-15 (IL-15), irisin, and Secreted protein acidic and rich in cysteine (SPARC) during the last decade and discussed possible reasons for discrepancy in these reports. AREAS COVERED: A search on PubMed for original articles published in this decade was conducted, focusing on the impacts of exercises on myokines and metabolic and age-related disorders. Beneficial relationship between skeletal muscle plasticity and myokines due to exercise is also discussed. EXPERT COMMENTARY: Based on these analyses, exercise induces the secretion of a number of myokines, which has positive effects on metabolic diseases or age-related muscle atrophy (sarcopenia). However, among published reports, there is wide discrepancy in the quantification of myokines induced by exercise, which could be due to timing of sample collection, pre-analytic sample processing, analytical method, and calculation and other factors. Thus, these factors need to be considered in future studies on exercise induced myokines.

A Data Set of Human Body Movements for Physical Rehabilitation Exercises.

The article presents University of Idaho - Physical Rehabilitation Movement Data (UI-PRMD) - a publically available data set of movements related to common exercises performed by patients in physical rehabilitation programs. For the data collection, 10 healthy subjects performed 10 repetitions of different physical therapy movements, with a Vicon optical tracker and a Microsoft Kinect sensor used for the motion capturing. The data are in a format that includes positions and angles of full-body joints. The objective of the data set is to provide a basis for mathematical modeling of therapy movements, as well as for establishing performance metrics for evaluation of patient consistency in executing the prescribed rehabilitation exercises.

Investigation of the Rosenbaum Concussion Knowledge and Attitudes Survey in Collegiate Athletes.

OBJECTIVE: The purpose of this study is to determine whether the Rosenbaum Concussion Knowledge and Attitudes Survey (RoCKAS) is an appropriate outcome measure to assess knowledge and attitudes toward concussion in collegiate student-athletes as determined through validity and reliability testing. STUDY DESIGN: Convenience study. SETTING: The researcher recruited all athletic teams at a Division III National Collegiate Athletic Association institution. PARTICIPANTS: Four hundred thirty-three collegiate student-athletes, 18 years of age or older, from a variety of sports took part in this study. As the validity of RoCKAS has never been established for the target population, this study randomly split respondents into 2 studies. INTERVENTIONS: Participants in this study completed the RoCKAS during preseason meetings before concussion education. The primary researcher was not present during the completion of the survey to allow participants to answer honestly without concern of coercion. MAIN OUTCOME MEASURES: A paper-based Rosenbaum Concussion Knowledge and Attitudes Survey. RESULTS: The Concussion Knowledge Index (CKI) was distributed in 2 cluster constructs and identified variables of low and high difficulty. Multivariate statistical analysis of the Concussion Attitude Index (CAI) explains 68.79% of the total variance. The Confirmatory Factor Analysis did not confirm the hypothesis that similar constructs can be found between data sets ((Equation is included in full-text article.)= 207.902; consistent akaike information criterion = 391.550; root mean square error of approximation = 0.125, and goodness of fit index = 0.868). CONCLUSIONS: The CKI is a valid and reliable measure in collegiate student-athletes. However, the results of the Confirmatory Factor Analysis indicated a poor model fit and improper correlations between attitude items. Therefore, the CAI may not be a sound outcome measure of collegiate student-athlete's attitudes toward concussions.

Unilateral Quadriceps Strengthening With Disinhibitory Cryotherapy and Quadriceps Symmetry After Anterior Cruciate Ligament Reconstruction.

CONTEXT: The effect of unilateral cryotherapy-facilitated rehabilitation exercise on involved-limb quadriceps function and limb symmetry in individuals with quadriceps dysfunction after anterior cruciate ligament reconstruction (ACLR) remains unclear. OBJECTIVE: To measure the effect of a 2-week unilateral cryotherapy-facilitated quadriceps-strengthening program on knee-extension strength and quadriceps central activation ratio (CAR) in participants with ACLR. DESIGN: Controlled laboratory study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 10 volunteers with unilateral ACLR (1 man, 9 women; age = 21.0 ± 2.8 years, height = 164.6 ± 5.0 cm, mass = 64.0 ± 6.1 kg, body mass index = 23.7 ± 2.7 kg/m2) and 10 healthy volunteers serving as control participants (1 man, 9 women; age = 20.8 ± 2.5 years, height = 169.1 ± 6.2 cm, mass = 61.1 ± 6.4 kg, body mass index = 21.4 ± 2.3 kg/m2) participated. INTERVENTION(S): Participants with ACLR completed a 2-week unilateral cryotherapy-facilitated quadriceps-strengthening intervention. MAIN OUTCOME MEASURE(S): Bilateral normalized knee-extension maximal voluntary isometric contraction (MVIC) torque (Nm/kg) and quadriceps CAR (%) were assessed preintervention and postintervention. Limb symmetry index (LSI) was calculated at preintervention and postintervention testing. Preintervention between-groups differences in unilateral quadriceps function and LSI were evaluated using independent-samples t tests. Preintervention-to-postintervention differences in quadriceps function were evaluated using paired-samples t tests. Cohen d effect sizes (95% confidence interval [CI]) were calculated for each comparison. RESULTS: Preintervention between-groups comparisons revealed less knee-extension MVIC torque and quadriceps CAR for the ACLR limb (MVIC: P = .01, Cohen d = -1.31 [95% CI = -2.28, -0.34]; CAR: P = .004, Cohen d = -1.48 [95% CI = -2.47, -0.49]) and uninvolved limb (MVIC: P = .03, Cohen d = -1.05 [95% CI = -1.99, -0.11]; CAR: P = .01, Cohen d = -1.27 [95% CI = -2.23, -0.31]) but not for the LSI (MVIC: P = .46, Cohen d = -0.34 [95% CI = -1.22, 0.54]; CAR: P = .60, Cohen d = 0.24 [95% CI = -0.64, 1.12]). In the ACLR group, participants had improved knee-extension MVIC torque in the involved limb ( P = .04, Cohen d = 0.32 [95% CI = -0.56, 1.20]) and uninvolved limb ( P = .03, Cohen d = 0.29 [95% CI = -0.59, 1.17]); however, the improvement in quadriceps CAR was limited to the involved limb ( P = .02, Cohen d = 1.16 [95% CI = 0.21, 2.11]). We observed no change in the LSI with the intervention for knee-extension MVIC torque ( P = .74, Cohen d = 0.09 [95% CI = -0.79, 0.97]) or quadriceps CAR ( P = .61, Cohen d = 0.26 [95% CI = -0.62, 1.14]). CONCLUSIONS: Two weeks of cryotherapy-facilitated exercise may improve involved-limb quadriceps function while preserving between-limbs symmetry in patients with a history of ACLR.

Acute effects of whole body vibration on balance in persons with and without chronic ankle instability.

Chronic ankle instability (CAI) is a common condition following ankle injury that is associated with compromised balance. Whole body vibration training (WBVT) programmes are linked with improved balance and function in athletic and non-athletic populations and may improve balance in CAI. Twelve healthy and seven CAI participants completed two randomly assigned interventions. Two Power Plate® platforms were attached back to back using a Theraband®. Participants stood on the active plate and inactive plate for WBVT and sham interventions, respectively. Each intervention included vibration of the active plate. Centre of pressure (COP) and the star excursion balance test (SEBT) were measured before and at 3, 15 and 30 min following the interventions. Significant improvements were found in the anterior direction of the SEBT following both interventions in CAI and varying patterns of improvement were observed for COP measurements in all participants. Therefore, WBVT does not appear to acutely improve balance in CAI.

Effects of reduced plantar cutaneous sensation on static postural control in individuals with and without chronic ankle instability.

OBJECTIVES: The purpose of this study was to determine how reduced plantar cutaneous sensation influences static postural control in individuals with and without CAI. DESIGN: A case-control study design. METHODS: Twenty-six individuals with self-reported CAI and 26 matched healthy controls participated in this study. The plantar aspect of the participants' foot was then submersed in ice water (0°C) for 10min to reduce plantar sensation. Before and after the cooling procedure, plantar cutaneous sensation thresholds and single leg balance with eyes open and closed were assessed. RESULTS: Significantly, higher scores were observed in both groups after ice water submersion (p<0.001) indicating a significant reduction in the plantar cutaneous sensitivity after the cooling procedure. In single limb balance with eyes open, there were significant intervention main effects for the TTB ML mean (p<0.001), TTB AP mean (p=0.035) and TTB ML SD (p=0.021); indicating postural control improvement in both groups post-cooling. In single limb balance with eyes closed, Group×Intervention interactions were observed for the TTB AP mean (p=0.003) and TTB AP SD (p=0.017); indicating postural control deficits in CAI group post-cooling, but no changes in the control group. CONCLUSIONS: The main finding of this study was that reduced plantar cutaneous sensation induced by an ice submersion procedure caused eyes closed postural control impairments in those with CAI but not healthy controls. The present investigation demonstrated that the ability to dynamically reweight among sensory inputs to maintain postural stability appears to be diminished in CAI patients compared to healthy controls.

Validation of the Microsoft Kinect® camera system for measurement of lower extremity jump landing and squatting kinematics.

Cost effective, quantifiable assessment of lower extremity movement represents potential improvement over standard tools for evaluation of injury risk. Ten healthy participants completed three trials of a drop jump, overhead squat, and single leg squat task. Peak hip and knee kinematics were assessed using an 8 camera BTS Smart 7000DX motion analysis system and the Microsoft Kinect® camera system. The agreement and consistency between both uncorrected and correct Kinect kinematic variables and the BTS camera system were assessed using interclass correlations coefficients. Peak sagittal plane kinematics measured using the Microsoft Kinect® camera system explained a significant amount of variance [Range(hip) = 43.5-62.8%; Range(knee) = 67.5-89.6%] in peak kinematics measured using the BTS camera system. Across tasks, peak knee flexion angle and peak hip flexion were found to be consistent and in agreement when the Microsoft Kinect® camera system was directly compared to the BTS camera system but these values were improved following application of a corrective factor. The Microsoft Kinect® may not be an appropriate surrogate for traditional motion analysis technology, but it may have potential applications as a real-time feedback tool in pathological or high injury risk populations.

Assessment of dynamic balance via measurement of lower extremities tortuosity.

Tortuosity describes how twisted or how much curvature is present in an observed movement or path. The purpose of this study was to investigate the differences in segmental tortuosity between Star Excursion Balance Test (SEBT) reach directions. Fifteen healthy participants completed this study. Participants completed the modified three direction (anterior, posteromedial, posterolateral) SEBT with three-dimensional motion analysis using an 8 camera BTS Smart 7000DX motion analysis system. The tortuosity of stance limb retro-reflective markers was then calculated and compared between reach directions using a 1 × 3 ANOVA with repeated measures, while the relationship between SEBT performance and tortuosity was established using Pearson product moment correlations. Anterior superior iliac spine tortuosity was significantly greater (p < 0.001) and lateral knee tortuosity was lesser (p = 0.018) in the anterior direction compared to the posteromedial and posterolateral directions. In addition, second metatarsal tortuosity was greater in the anterior reach direction when compared to posteromedial direction (p = 0.024). Tortuosity is a novel biomechanical measurement technique that provides an assessment of segmental movement during common dynamic tasks such as the SEBT. This enhanced level of detail compared to more global measures of joint kinematic may provide insight into compensatory movement strategies adopted following lower extremity joint injury.