Plyometric training effects on physical fitness and muscle damage in high school baseball players.

PURPOSE: The objective of this study was to investigate the effects of plyometric training on physical fitness and muscle damage in high school baseball players. METHODS: The participants in the study included 21 high school baseball players who are healthy and well-training. The participants were randomly allocated to the plyometric training (n=11) and control (n=10) groups. The plyometric training was applied 3 times a week for a total of 8 weeks and the control group took part in only regular baseball skills training without plyometric training. For physical fitness, measures included maximal strength (left and right hand-grip strength), muscle endurance (sit-up), agility (side-step), power (standing long jump), and balance (left and right Rhomberg test). For muscle damage, creatine kinase (CK) and lactate dehydrogenase (LDH) levels were measured. RESULTS: The results showed a significant interaction effect between time and groups in left hand-grip strength (P = 0.022), side-step (P = 0.004), and standing long jump (P < 0.001) after the 8-week plyometric training, with greater improvement in the plyometric training group than the control group. On the other hand, there was no significant interaction effect between time and groups in right hand-grip strength, situp, left and right Rhomberg test, CK level, and LDH level (P > 0.05). CONCLUSION: In conclusion, 8-week plyometric training had a positive effect on improving physical fitness, such as maximal strength, agility, and power, in high school baseball players without causing additional muscle damage.

Prevalence of obesity in korean adolescents and its relationship with the weekly frequency of the physical education classes.

The purpose of this study was to investigate differences in the prevalence of obesity among Korean adolescents and to determine the relationship of obesity prevalence with weekly frequency of physical education (PE) classes. In 2009, 72,399 students from grades 7 to 12 participated in the fifth Korea Youth Risk Behavior Web-based Survey (KYRBWS-V) project. Body mass index (BMI) and the frequency of PE classes attended were assessed by the KYRBWS- V. BMI was computed to classify the participants as underweight, normal weight, overweight, and obese. The association between the frequency of PE classes and BMI were examined using one-way ANOVA and logistic regression analysis. The differences in the weekly frequency of PE classes and the BMI values among both the boys and girls were significant (p < 0.001). A post-hoc test showed that underweight boys and girls attended the PE classes more frequently (p < 0.001), and overweight girls attended these classes less frequently (p < 0.01) than the other groups did; moreover, obese boys and girls, compared to boys and girls in the other groups, attended less number of PE classes per week while at school (p < 0.05). Besides, the odds ratio (95% confidence interval, CI) for normal-weight vs. underweight boys attending 1 PE class, 2 PE classes, and ≥ 3 PE classes per week were 1.168 (1.011-1.349, p = 0.035), 1.621 (1.450-1.812, p < 0.001), and 3.023 (2.704-3.381, p < 0.001), respectively, compared with those for boys who did not attend PE classes. The OR (95% CI) of normal-weight vs. obese boys attending ≥ 3 PE classes attended across normal vs. obese boys was 0.862 (0.762-0.974, p = 0.017), compared with those of boys who did not attend PE classes. The OR (95% CI) for normal-weight vs. underweight girls who attended 2 PE classes and ≥ 3 PE classes per week were 1.235 (1.131-1.349, p < 0.001) and 2.238 (2.048-2.446, p < 0.001), respectively, compared with those of girls who did not attend PE classes. The OR (95% CI) of for normal-weight vs. overweight girls who attended ≥ 3 PE classes per week were 0.886 (0.787- 0.997, p = 0.045) and 0.772 (0.679-0.878, p < 0.001), respectively, compared with those of girls who did not attend PE classes. The OR (95% CI) for normal-weight vs. obese girls who attended 2 PE classes and ≥ 3 PE classes per week were 0.788 (0.675-0.919, p = 0.002) and 0.709 (0.599-0.838, p < 0.001), respectively, compared with those of girls who did not attend the PE class. Increase in the frequency of PE classes should be considered in any attempt for curbing weight-related problems in Korean adolescents. Key pointsIncrease in the frequency of PE classes is a factor that should be considered to improve weight status.

The effects of instrument-assisted soft tissue mobilization rehabilitation exercise on range of motion, isokinetic strength, and balance in chronic ankle instability taekwondo players.

We aimed to investigate change the instrument-assisted soft tissue mobilization (IASTM) rehabilitation exercise on range of motion (ROM), isokinetic ankle strength, and balance. We included 20 elite taekwondo players (chronic ankle instability) in Korea. They were divided into the IASTM group (n=10), control group (n=10). IASTM group were exercised with IASTM rehabilitation exercise four times per week for 8 weeks. The remaining control group did not receive exercise intervention between tests and served as the control. A goniometer was used to measure dorsi-flexion (D/F), plantar-flexion (P/F), a dynamometer was used to measure ankle isokinetic strength, and plantar foot pressure was used to measure static balance. The data were analyzed using repeated-measures analysis of variance. Significant differences were observed between the two groups in IASTM group and control group: ROM (right P/F, P<0.001; right D/F, P<0.01; left P/F, P<0.000; left D/F, P<0.000), isokinetic strength (right P/F 60°, P<0.000; right D/F 60°, P<0.000; left P/F 60°, P<0.000; left D/F 60°, P<0.000; right P/F 180°, P<0.000; right D/F 180°, P<0.000; left: P/F 180°, P<0.000, left D/F 180°, P<0.000), and balance test (static eye open, P<0.000; static eye close, P<0.000; postural stability, P<0.041). These results suggest that IASTM rehabilitation exercise improves ankle stability, muscle power, and body balance in chronic ankle instability taekwondo players.

The effects of instrument-assisted soft tissue mobilization on active range of motion, functional fitness, flexibility, and isokinetic strength in high school basketball players.

Although many studies have focused on stretching techniques for athletes, no comprehensive studies have investigated the use of the instrument-assisted soft tissue mobilization (IASTM) technique in young basketball players. The active properties of muscle and subjective reporting of functional ability were used to identify the effects of IASTM on the calf muscle. Active range of motion (AROM), functional fitness, and isokinetic lower strength in the knees and ankles were measured in 40 healthy young basketball players. They were divided into the IASTM group (n= 20) and a control group (CG, n= 20). Twenty asymptomatic young basketball players were treated with IASTM six times per week for 8 weeks. The remaining 20 participants did not receive a treatment intervention between tests and served as the control. Ankle AROM (two knee positions of 0∘ and 45∘ flexion), functional fitness at the knee and ankle (side-step and vertical jump), and isokinetic peak torque were determined during ankle dorsiflexion (DF) and plantar flexion (PF) and knee extension (EX) and flexion (FX). The data were analyzed using repeated-measures analysis of variance. Significant differences were observed between the two groups in IASTM and control AROM 0∘ knee flexion (right: DF; p< 0.001 and PF; p< 0.001; left: DF; p< 0.001 and PF; p= 0.011), AROM 45∘ knee flexion (right: DF; p< 0.001 and PF; p= 0.009; left: DF; p< 0.001 and PF; p= 0.001), functional fitness (side step; p= 0.001, sit and reach; p= 0.025, vertical jump; p= 0.001), ankle isokinetic strength 30∘/sec (right: DF; p= 0.001 and PF; p= 0.001; left: DF; p< 0.001 and PF; p= 0.002), ankle isokinetic strength 120∘/sec (right: DF; p= 0.049 and PF; p= 0.001; left: DF; p= 0.023 and PF; p< 0.001), knee isokinetic strength 60∘/sec (right: EX; p= 0.001, FX; p= 0.001 and hamstring and quadriceps ratio [H/Q]; p= 0.001, left: EX; p= 0.001, FX; p= 0.001 and H/Q; p= 0.001), and knee isokinetic strength 180∘/sec (right: EX; p= 0.001, FX; p= 0.001 and H/Q; p= 0.001; left: EX; p= 0.001, FX; p= 0.010 and H/Q; p= 0.001). These results suggest that IASTM improves functional fitness and lower body muscle strength in young basketball players.

Effects of accelerated rehabilitation exercise after mbo on ankle function and strength in ankle instability / Efectos del ejercicio de rehabilitación acelerada después de tbm sobre la función y la fuerza en la inestabilidad del tobillo / Efeitos do exercício de reabilitação acelerada depois de tbm sobre a função e a força na instabilidade do tornozelo

ABSTRACT Background: Taekwondo athletes with lateral chronic ankle instability (LCAI) may experience difficulties with proprioception and ankle muscle strength. After surgery, a conventional rehabilitation exercise program can be ineffective, as it may not restore proprioception or muscle strength and, thus, result in minimal improvement. Objective: This study aimed to assess the effects of an ARE program following MBO on the proprioception, isokinetic strength, and endurance of ankle. Methods: Thirty athletes diagnosed with LCAI underwent MBO. They were divided into the ARE group (n=15) and the control group (CON, n=15). The ARE group performed early ARE exercises six times per week for 4 weeks. The parameters applied to test ankle muscle strength were angular speed of 30°/sec and 180°/sec (inversion: Inv. and eversion: Eve., respectively). Proprioception was measured as being able to sense a joint position of 15° of Inv. and 5° of Eve. Results: Significant differences were observed between the ARE and CON groups in ankle strength 30°/sec (Inv.: p<0.001, Eve.: p<0.001), 180°/sec (Inv.: p<0.001, Eve.: p<0.001), and proprioception at 15° (Inv.: p<0.001) and 5° (Eve.: p<0.001). Conclusions: We recorded significant short-term effects from early ARE in Taekwondo athletes with LCAI after MBO. The results provide reference data for the sports rehabilitator or ATC in evaluating the rehabilitation phase and informing patients about expectations after MBO in terms of performance status and the timing of return to sports. Level of evidence III; Therapeutic studies-Investigation of treatment outcomes - Case-control Study.

RESUMEN Introducción: Los atletas de Tae Kwon Do con inestabilidad lateral crónica del tobillo (ILCT) pueden presentar dificultades con la propiocepción y la fuerza muscular del tobillo. Después de la cirugía, un programa convencional de ejercicios de rehabilitación puede ser ineficaz porque la propiocepción o la fuerza muscular pueden no restablecerse y, por tanto, dar lugar a una mejora mínima. Objetivos: Este estudio tuvo como objetivo evaluar los efectos de un programa de ERA después de TBM sobre la propiocepción, la fuerza isocinética y la resistencia del tobillo. Métodos: Treinta atletas diagnosticados con ILCT fueron sometidos a TBM. Se dividieron en grupo ERA (n=15) y grupo de control CON (n = 15). El grupo de ERA realizó ejercicios ERA precoces seis veces por semana durante 4 semanas. Los parámetros aplicados para probar la fuerza muscular del tobillo fueron la velocidad angular de 30°/s y 180°/s (inversión: Inv y eversión: Eve, respectivamente). La propiocepción se midió por la capacidad de sentir la posición articular de 15° de Inv y 5° de Eve. Resultados: Se observaron diferencias significativas entre los grupos ERA y CON en la fuerza del tobillo a 30°/s (Inv: p < 0,001, Eve: p < 0,001), 180°/s (Inv: p < 0,001, Eve: p < 0,001), y la propiocepción a 15° (Inv: p < 0,001) y 5° (Eve: p < 0,001). Conclusiones: Registramos efectos significativos a corto plazo con ERA precoz en atletas de Tae Kwon Do con ILCT después de TBM. Los resultados proporcionan datos de referencia para el rehabilitador deportivo o ATC (Certified athletic trainer) a la hora de evaluar la fase de rehabilitación e informar a los pacientes sobre las expectativas después de la TBM en cuanto a las condiciones de desempeño y el momento de retorno al deporte. Nivel de evidencia III; Estudios terapéuticos - Investigación de los resultados del tratamiento - Estudio de caso-control

RESUMO Introdução: Os atletas de taekwondo com instabilidade lateral crônica do tornozelo (ILCT) podem apresentar dificuldades com propriocepção e força muscular do tornozelo. Depois da cirurgia, um programa de exercícios de reabilitação convencional pode ser ineficaz, porque a propriocepção ou a força muscular podem não se restaurar e, portanto, resultar em melhora mínima. Objetivos: Este estudo teve como objetivo avaliar os efeitos de um programa de ERA depois de TBM sobre a propriocepção, força isocinética e resistência do tornozelo. Métodos: Trinta atletas com diagnóstico de ILCT foram submetidos à TBM. Eles foram divididos em grupo ERA (n=15) e grupo controle CON (n = 15). O grupo ERA realizou exercícios ERA precoces seis vezes por semana durante 4 semanas. Os parâmetros aplicados para testar a força muscular do tornozelo foram velocidade angular de 30°/s e 180°/s (inversão: Inv e eversão: Eve, respectivamente). A propriocepção foi medida pela capacidade de sentir a posição articular de 15° de Inv e 5° de Eve Resultados: Foram observadas diferenças significativas entre os grupos ERA e CON na força do tornozelo 30°/s (Inv: p < 0,001, Eve: p < 0,001), 180°/s (Inv: p < 0,001, Eve: p < 0,001), e propriocepção a 15° (Inv: p < 0,001) e 5° (Eve: p < 0,001). Conclusões: Registramos efeitos de curto prazo significativos com ERA precoce em atletas de taekwondo com ILCT depois da TBM. Os resultados fornecem dados de referência para o reabilitador esportivo ou ATC (Certified athletic trainer) na avaliação da fase de reabilitação e informar os pacientes sobre as expectativas depois da TBM em termos de condições de desempenho e momento de retorno ao esporte. Nível de evidência III; Estudos terapêuticos - Investigação dos resultados do tratamento - Estudo de caso-controle.

The effects of training on different surfaces, on balance and gait performance in stroke hemiplegia / Efectos del entrenamiento sobre el equilibrio y el desempeño de la marcha en diferentes superficies de apoyo en la hemiplejia inducida por accidente cerebrovascular / Efeitos do treinamento em diferentes superfícies de apoio sobre o equilíbrio e o desempenho da marcha em hemiplegia por acidente vascular cerebral

ABSTRACT Although many studies have focused on balance exercises for elderly or stroke patients, no comprehensive studies have investigated the use of training on different surfaces (TDS) with analysis of gait performance in elderly male stroke patients. The active properties of balance and subjective reporting of functional gait ability were used to identify the effects of TDS. Static balance (SB), dynamic balance (DB) and gait analysis was measured in 30 elderly stroke patients. The patients were divided into the TDS group (n=15) and a control group (CG, n=15). Fifteen elderly stroke patients underwent TDS five times a week for 12 weeks. The data was analyzed using repeated measures analysis of variance. Significant differences were observed between the two groups (TDS and Control): SB (p < 0.0001), DB (OSI: p < 0.0001, APSI: p < 0.001, MLSI: p < 0.004) and gait analysis (right: temporal step time: p < 0.0001, temporal cycle time: p < 0.001, temporal double support time: p < 0.0001; left: temporal step time: p < 0.0001, temporal cycle time: p < 0.0001, temporal double support time: p < 0.0001). TDS in elderly male stroke patients suggests that the characteristics of gait performance in these patients may be improved by increasing static balance, dynamic balance and gait velocity. It is hoped that the results of this trial will provide new information on the effects of TDS on balance stability and gait ability in stroke patients, through changes in stability of the lower extremities. Level III, Case-control Study.

RESUMEN Aunque muchos estudios se han centrado en los ejercicios de equilibrio para pacientes de edad avanzada y/o con accidentes cerebrovasculares, ningún estudio exhaustivo ha investigado el uso del entrenamiento en diferentes superficies de apoyo (TDS) para analizar el desempeño de la marcha en pacientes masculinos de edad avanzada con accidentes cerebrovasculares. Se utilizaron las propiedades activas del equilibrio y el informe subjetivo de la capacidad funcional de la marcha para identificar los efectos del TDS. Se midieron el equilibrio estático (SB), el equilibrio dinámico (DB) y el análisis de la marcha en 30 pacientes ancianos con ACV. Los pacientes fueron divididos en grupo TDS (GTDS, n = 15) y grupo de control (CG, n = 15). Quince pacientes de edad avanzada con ACV fueron sometidos a TDS cinco veces por semana durante 12 semanas. Los datos se analizaron mediante un análisis de desviación de medidas repetidas. Se observaron diferencias significativas entre los dos grupos (TDS y Control): SB (p <0,0001), DB (OSI: p <0,0001, APSI: p <0,001, MLSI: p <0,004) y análisis de la marcha (derecha: tiempo de paso temporal: p <0,0001, tiempo de ciclo temporal: p <0,001, tiempo de doble apoyo temporal: p <0,0001; izquierda: tiempo de paso temporal: p <0,0001, tiempo de ciclo temporal: p <0,0001, tiempo de doble apoyo temporal: p <0,0001). El TDS en pacientes masculinos de edad avanzada con ACV sugiere que las características de desempeño de la marcha pueden mejorar con el aumento del equilibrio estático, el equilibrio dinámico y la velocidad de la marcha. Se espera que los resultados de este estudio proporcionen nueva información sobre los efectos del TDS en la estabilidad del equilibrio y en la capacidad de andar en pacientes con ACV a través de cambios en la estabilidad de las extremidades inferiores. Nivel de evidencia III, Estudio de caso-control.

RESUMO Embora muitos estudos tenham se concentrado em exercícios de equilíbrio para idosos e/ou pacientes com acidente vascular cerebral, nenhum estudo abrangente investigou o uso do treinamento em diferentes superfícies de apoio (TDS) para analisar o desempenho da marcha em pacientes idosos do sexo masculino com AVC. As propriedades ativas do equilíbrio e o relato subjetivo da capacidade funcional da marcha foram usados para identificar os efeitos do TDS. O equilíbrio estático (SB), o equilíbrio dinâmico (DB) e a análise da marcha foram medidos em 30 pacientes idosos com AVC. Os pacientes foram divididos em grupo TDS (GTDS, n = 15) e grupo controle (GC, n = 15). Quinze pacientes idosos com AVC foram submetidos a TDS cinco vezes por semana durante 12 semanas. Os dados foram analisados por meio de análise de variância de medidas repetidas. Foram observadas diferenças significativas entre os dois grupos (GTDS e controle): SB (p < 0,0001), DB (OSI: p < 0,0001, APSI: p < 0,001, MLSI: p < 0,004) e análise da marcha (direita: tempo do passo: p < 0,0001, tempo da passada (ciclo): p < 0,001, tempo de duplo apoio: p < 0,0001; esquerda: tempo do passo: p < 0,0001, tempo da passada (ciclo): p < 0,0001, tempo de duplo apoio: p <0,0001). O TDS em pacientes idosos do sexo masculino com AVC sugere que as características de desempenho da marcha podem ser melhoradas com o aumento do equilíbrio estático, equilíbrio dinâmico e da velocidade da marcha. Espera-se que os resultados deste estudo forneçam novas informações sobre os efeitos do TDS na estabilidade do equilíbrio e na habilidade de marcha em pacientes com AVC, por meio de mudanças na estabilidade dos membros inferiores. Nível de evidência III, Estudo de caso controle.

The effects of landed and aquatic treadmill walking at moderate intensity on heart rate, energy expenditure and catecholamine.

PURPOSE: The present study was to examine whether or not the appropriate exercise intensity of water-walking could be accurately prescribed by land-based walking speed. METHODS: Using a crossover design, nine healthy male college students completed bouts of walking for thirty minutes at 100m/min, 50m/min, respectively, on land and water treadmills. Heart rate (HR), ratings of perceived exertion (RPE), energy expenditure, blood lactic acid and catecholamine concentration were measured. Two-way repeated measured ANOVA was used with the SPSS program for data analysis. RESULTS: HR (P < 0.001), RPE (P < 0.001), energy expenditure (P < 0.001), blood lactic acid (P < 0.001) and epinephrine concentration (P < 0.05) were significantly increased during walking both in water and on land. The change of HR was significantly lower at 50min/m in water than 100min/m on land (P < 0.01). There were no significant interaction effects for RPE, energy expenditure, blood lactic acid and catecholamine concentration, but these variables were slightly lower in water than on land. These results indicated that the use of land walking speed-based prescriptive norms would underestimate the physiological cost in water walking at the moderate intensity. CONCLUSION: Therefore, approximately two-half of the speed would be needed to walk in water in order to obtain the same level of physiological load as during treadmill walking at the moderate intensity.

Analysis of Range of Motion and Isokinetic Strength of Internal and External Rotation According to Humeral Retroversion of the Dominant Shoulder in Youth Baseball Players: A Pilot Study.

BACKGROUND: We aimed to analyze the range of motion (ROM) and internal rotation (IR) and external rotation (ER) isokinetic strength according to humeral retroversion of the dominant shoulder. METHODS: We included 40 elite baseball players in Korea (OBP group: n=20 players with careers spanning >10 years, age: 19.37±2.21 years, height: 181.00±5.41 cm, weight: 84.58±7.85 kg; BBP group: n=20 players with careers spanning <10 years, age: 16.55±1.36 years, height: 177.27±7.57 cm, weight: 77.27±8.14 kg). Radiography was performed to examine humeral retroversion, a goniometer was used to measure IROM and EROM, and a dynamometer was used to measure IR and ER isokinetic strength (speed set at 180°/s or 300°/s). RESULTS: The BBP and OBP groups had significantly different IR and ER isokinetic strength (180°/s and 300°/s) (P<0.001) and dominant shoulder retroversion (P=0.009). In the BBP group, retroversion had no correlation with ROM and with IR or ER isokinetic strength (180°/s and 300°/s). In the OBP group, retroversion had no correlation with ROM and with ER isokinetic strength at 180°/s, but had significant correlation with IR isokinetic strength at both 180°/s (r=0.483, P=0.007) and 300°/s (r=0.373, P=0.043) and ER isokinetic strength at 300°/s (r=0.366, P=0.046). CONCLUSION: Thus, youth players with careers spanning >10 years had significantly higher humeral retroversion, IROM, EROM, and IR and ER isokinetic strength of the dominant shoulder than youth players with careers spanning <10 years. Furthermore, humeral retroversion and ROM were not significantly related, but IR and ER isokinetic strength were significantly positively related with retroversion in both groups.