Journal of Human Kinetics最新文献_第6页

Temporal Trends of Linear Speed and Change of Direction Performance in Italian Children. 意大利儿童线性速度和方向变化表现的时间趋势。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/189745

Matteo Vandoni, Alessandro Gatti, Vittoria Carnevale Pellino, Caterina Cavallo, Agnese Pirazzi, Matteo Giuriato, Nicola Lovecchio

{"title":"Temporal Trends of Linear Speed and Change of Direction Performance in Italian Children.","authors":"Matteo Vandoni, Alessandro Gatti, Vittoria Carnevale Pellino, Caterina Cavallo, Agnese Pirazzi, Matteo Giuriato, Nicola Lovecchio","doi":"10.5114/jhk/189745","DOIUrl":"10.5114/jhk/189745","url":null,"abstract":"Children tend to enjoy high-intensity activities that involve both linear speed (LS) and change of direction (COD), essential for sports performance. However, the results of trends in LS and COD have not been consistent over time. Therefore, our study aimed to investigate the temporal trends in LS and COD performance among 11-13 year old Italian children/preadolescents over 25 years, while minimizing the effect of anthropometric characteristics. A total of 3884 students were recruited between 1990 and 2010 and performed 4 x 5-m shuttle run, 30-m sprint, and 60-m speed tests. A weighted linear regression was performed to analyze the overall temporal trends in BMI-adjusted speed tests. The results showed an increase in mean 4 x 5-m shuttle run time, indicating a decrease in COD ability, while LS performance remained relatively stable over time. These trends were consistent across genders and ages. Our study concludes that LS test performance remained steady over decades, while COD ability declined with sex-based variations despite participants' early age. Our results offer crucial data for interventions to improve children's physical fitness: in particular for COD performance. PE teachers and coaches should prioritize improving COD over LS to improve these abilities and prevent physical fitness decline.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"215-226"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812156/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Velocity Loss as an Indicator of Resistance Training Volume in Women. 速度损失作为女性阻力训练量的指标。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/190387

Beatriz Bachero-Mena, Luis Rodiles-Guerrero, Juan Sánchez-Valdepeñas, Pedro J Cornejo-Daza, Clara Cano-Castillo, Fernando Pareja-Blanco, Miguel Sánchez-Moreno

{"title":"Velocity Loss as an Indicator of Resistance Training Volume in Women.","authors":"Beatriz Bachero-Mena, Luis Rodiles-Guerrero, Juan Sánchez-Valdepeñas, Pedro J Cornejo-Daza, Clara Cano-Castillo, Fernando Pareja-Blanco, Miguel Sánchez-Moreno","doi":"10.5114/jhk/190387","DOIUrl":"10.5114/jhk/190387","url":null,"abstract":"This study aimed to analyze the evolution of repetition velocity throughout a set until failure in the bench-press exercise and to analyze the relationships between the percentage of performed repetitions (%Rep) regarding the maximum number of repetitions that can be completed (MNR) and the percentage of velocity loss (VL) in women. Sixteen women performed one set until failure with four different intensities (50%, 60%, 70%, and 80% of one-repetition maximum, 1RM). Two-testing sessions were performed with 50% and 80% 1RM to evaluate data stability. The level of significance was set at p ≤ 0.05. A close relationship was observed between the magnitude of VL and the %Rep (R2 = 0.85-0.92) and a low standard error of the estimation (6.85-9.81%). Regarding reliability, the MNR showed a coefficient of variation (CV) of 16.1% and 20.8% for 50% and 80% 1RM, respectively. Regarding the %Rep for a given VL (from 15% VL), CVs were: 6.3-19.6%, being higher when VL reached in the set was lower. This study shows the usefulness of monitoring VL to estimate, with considerable precision, the %Rep in women. However, the %Rep when a given VL was reached revealed only satisfactory absolute reliability from a certain VL threshold (>15% VL).","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"111-122"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812168/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Area per Player in Small-Sided Games to Estimate the External Load in Elite Youth Soccer Players. 小型比赛中每个球员的面积估算精英青年足球运动员的外部负荷。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/189421

Vicente de Dios-Álvarez, Alexis Padrón-Cabo, Pello Alkain-Villa, Ezequiel Rey, Julen Castellano

{"title":"Area per Player in Small-Sided Games to Estimate the External Load in Elite Youth Soccer Players.","authors":"Vicente de Dios-Álvarez, Alexis Padrón-Cabo, Pello Alkain-Villa, Ezequiel Rey, Julen Castellano","doi":"10.5114/jhk/189421","DOIUrl":"10.5114/jhk/189421","url":null,"abstract":"Small-sided games (SSGs) refer to game formats where there are variations in the pitch size, the number of players, and rules as compared to official soccer matches. The purpose of this study was to assess the relationship between GPS-derived external loads and the SSGs' area per player (ApP) in elite youth soccer players to identify whether the ApP influenced GPS-derived external load measures to estimate external load variables from SSGs with different densities (i.e., ApP100: the ApP <150 m2•player-1; ApP200: the ApP ranged from 151 to 250; ApP300: the ApP > 251 m2•player-1). A cumulative count of 978 individual observations was undertaken, encompassing 15 diverse SSG configurations. The results showed moderate and large correlations between the ApP and external load measures for both U19 and U16 soccer players. The ApP300 induced higher locomotor activities than the ApP100 and the ApP200. However, the ApP100 showed higher mechanical (accelerations and decelerations) values compared to ApP200 and ApP300 conditions for both age groups. It was found that an ApP of less than 150 m2•player-1 in SSGs did not stimulate enough high-speed distance relative (HSDR), very high-speed distance relative (VHSDR) and sprint distance relative (SDR) compared to official matches in youth soccer players. However, the same ApP overestimated mechanical variables such as total high accelerations and decelerations relative to time (THACCR and THDECR, respectively). The findings of this study have the potential to facilitate the effective management of training loads tailored to specific fitness components of players.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"123-138"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812169/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Does the Length of Inter-Set Rest Periods Impact the Volume of Bench Pull Repetitions Completed before Surpassing Various Cut-Off Velocities? 间歇休息时间的长短会影响在超过各种截止速度之前完成的卧拉重复量吗？

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/188366

Danica Janicijevic, Sergio Miras-Moreno, María Dolores Morenas-Aguilar, Amador García-Ramos

{"title":"Does the Length of Inter-Set Rest Periods Impact the Volume of Bench Pull Repetitions Completed before Surpassing Various Cut-Off Velocities?","authors":"Danica Janicijevic, Sergio Miras-Moreno, María Dolores Morenas-Aguilar, Amador García-Ramos","doi":"10.5114/jhk/188366","DOIUrl":"10.5114/jhk/188366","url":null,"abstract":"This study aimed to determine the optimal inter-set rest periods that would maximize the number of repetitions completed before surpassing various cut-off velocities (COVs) during the prone bench pull exercise. Twenty-three physically active individuals, 15 men and 8 women, participated in six random testing sessions. Each session included four sets of the prone bench pull exercise performed with maximum intent on a Smith machine at 75% of the one-repetition maximum (1RM). The length of the inter-set rest interval (1 [R1], 3 [R3], and 5 [R5] min) and COV used (0.65 m•s-1 [COV0.65] and 0.55 m•s-1 [COV0.55]) varied between sessions. Longer inter-set rest periods led to a higher volume of repetitions (R5 > R3 > R1), whereas the differences between the rest protocols were larger for COV0.55 (R1: 28.4 ± 6.0 repetitions; R3: 36.4 ± 9.4 repetitions; R5: 41.1 ± 11.4 repetitions) compared to COV0.65 (R1: 24.2 ± 7.3 repetitions; R3: 25.4 ± 10.1 repetitions; R5: 28.3 ± 9.7 repetitions). Increasing the number of sets negatively impacted the number of completed repetitions for R1 using both COV0.65 and COV0.55, as well as for R3 using COV0.55. The fastest velocity of the set (MVfastest) did not differ between the inter-set rest protocols for COV0.65, while for COV0.55, R3 and R5 provided a greater MVfastest than R1 for sets 2-4. These findings suggest that the duration of inter-set rest periods is an important factor to consider when aiming to maximize mechanical performance across multiple sets of the prone bench pull exercise.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"139-150"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812172/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143407726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prevalence of Eating Disorders and Self-Perception Concerning Body Composition Analysis among Elite Soccer Players. 优秀足球运动员身体成分分析中饮食失调和自我认知的患病率。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/194464

Wiktoria Staśkiewicz-Bartecka, Grzegorz Zydek, Małgorzata Magdalena Michalczyk, Marek Kardas

{"title":"Prevalence of Eating Disorders and Self-Perception Concerning Body Composition Analysis among Elite Soccer Players.","authors":"Wiktoria Staśkiewicz-Bartecka, Grzegorz Zydek, Małgorzata Magdalena Michalczyk, Marek Kardas","doi":"10.5114/jhk/194464","DOIUrl":"10.5114/jhk/194464","url":null,"abstract":"In the field of mental health, eating disorders (EDs) are an important subject of research, especially regarding athletes. This study examined the risk of EDs, orthorexia nervosa (ON), and body perception among elite soccer players, focusing on the impact of body composition. Conducted from March to April 2024 with 51 players from the elite and 1st division clubs, the research utilized the Eating Attitudes Test (EAT-26), the Düsseldorf Orthorexia Scale (DOS), and the Body Esteem Scale (BES) alongside body composition analysis via Direct Segmental Multi-Frequency Bioelectrical Impedance Analysis (DSM-BIA). Findings indicated a significant prevalence of ED risk among players, with more than half showing potential symptoms. Body composition analyses revealed that players with a higher fat mass had an increased ED risk, while muscle mass did not correlate significantly with ED attitudes. Regarding ON, approximately one-third of athletes were at risk, although no significant relationship was found between ON and body composition variables. In terms of body image, players generally viewed their bodies moderately, rating physical fitness, sex drive, and health positively. However, a higher body fat was associated with lower ratings in upper body strength, indicating perceived physical limitations. This study highlights the necessity for targeted interventions to manage the high prevalence of EDs among elite soccer players and promote healthier body image perceptions, emphasizing the low relationship between body esteem and the likelihood of developing EDs or ON.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"259-272"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812158/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantifying Quadriceps Forces during Running Performed with and without Infrapatellar Straps. 量化在有或没有髌下绑带的情况下跑步时的股四头肌力量。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/190143

Xueying Zhang, Weiyan Ren, Xingyue Wang, Jie Yao, Fang Pu

{"title":"Quantifying Quadriceps Forces during Running Performed with and without Infrapatellar Straps.","authors":"Xueying Zhang, Weiyan Ren, Xingyue Wang, Jie Yao, Fang Pu","doi":"10.5114/jhk/190143","DOIUrl":"10.5114/jhk/190143","url":null,"abstract":"Running-related knee injuries are associated with high and repetitive quadriceps contractions. Infrapatellar straps are commonly recommended for the prevention and management of those injuries. The effects of infrapatellar straps have been investigated in terms of quadriceps activations. However, these indexes cannot accurately characterize the quadriceps forces, which directly contribute to knee injuries. This study aimed to quantify quadriceps forces during running performed with and without infrapatellar straps based on OpenSim. Experimental data from 18 healthy participants were recorded using a 10-camera motion capture system and two force plates when they performed running at self-selected speeds with and without infrapatellar straps. OpenSim was used to estimate muscle forces, muscle activity, joint kinematics, and joint kinetics. The use of infrapatellar straps significantly reduced peak quadriceps forces (p < 0.001), accumulated forces of quadriceps (p < 0.001), and peak knee extension moments (p < 0.001). Among the four distinct muscles of the quadriceps, the vastus lateralis contributed the most to the reduction in quadriceps muscle forces. Strapping did not result in a significant change in rectus femoris forces (p > 0.05). The use of infrapatellar straps results in lower vastus muscle forces, and thus could be helpful in managing and preventing running-related knee injuries. However, infrapatellar straps may have little effect in people with an excessively forceful rectus femoris.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"29-42"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812163/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring the Impact of Social Relationship Modification on Young Female Soccer Players' Performance in Small-Sided Games. 探讨社会关系调整对青少年女子足球小边比赛成绩的影响。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/189425

Asier Los Arcos, Asier Gonzalez-Artetxe, Sara Lombardero, Oihan Esnal-Arrizabalaga, Jokin Aginaga

{"title":"Exploring the Impact of Social Relationship Modification on Young Female Soccer Players' Performance in Small-Sided Games.","authors":"Asier Los Arcos, Asier Gonzalez-Artetxe, Sara Lombardero, Oihan Esnal-Arrizabalaga, Jokin Aginaga","doi":"10.5114/jhk/189425","DOIUrl":"10.5114/jhk/189425","url":null,"abstract":"This study compared young female soccer players' tactical, conditional, and emotional responses during two small-sided games (SSGs), without restrictions (SSGfree), and introducing an additional rule (SSGrelationship: if a player touches an opponent just before she receives the ball, her team wins the ball back with an indirect free kick). Fourteen developmental U14 players participated in two 4 × 6-min seven-a-side games (six each, plus goalkeepers) on a 50-m long × 30-m wide field. Players' positional data were collected using a GPS to assess their tactical performance (central tendency and entropy measures of the surface area, distance between players and to the nearest opponent, and stretch and spatial exploration indices) and conditional performance (total and low-moderate, high, very high speed, sprinting distance covered, and the number of accelerations and decelerations). Participants also rated their perceived enjoyment and competence using the BECS scale. Tactical central tendency measures were higher during SSGfree (p < 0.05) than in SSGrelationship, but no differences were apparent for entropy and conditional measures (p > 0.05). From bout to bout, central tendency measures of tactical variables decreased more frequently during SSGfree than SSGrelationship. Entropy measures and conditional performance hardly varied between bouts. Enjoyment and perceived competence levels were similar for both SSGs. The findings indicate that modifying the interaction between opponents affects players' tactical responses more than conditional responses when compared with free play. Specifically, touching an opponent before they receive the ball may encourage players to play closer to their opponents during training tasks.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"227-241"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812164/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Threshold Pressure Loading Exercises Applied to Inspiratory Muscles in Taekwondo Athletes on the Concentration and Utilization of Lactate. 跆拳道运动员吸气肌阈值压力负荷训练对乳酸浓度和利用的影响。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-12-06 eCollection Date: 2025-01-01 DOI: 10.5114/jhk/188542

Murat Koç, Nazmi Sarıtaş, Betül Coşkun, Soner Akkurt

{"title":"Effects of Threshold Pressure Loading Exercises Applied to Inspiratory Muscles in Taekwondo Athletes on the Concentration and Utilization of Lactate.","authors":"Murat Koç, Nazmi Sarıtaş, Betül Coşkun, Soner Akkurt","doi":"10.5114/jhk/188542","DOIUrl":"10.5114/jhk/188542","url":null,"abstract":"This study examined the effects of different inspiratory muscle training (IMT) on lactate concentration and utilization during high-intensity exercises. Participants were divided into the following three groups: a chronic inspiratory training group (CRG), an acute inspiratory training group (ARG), and a control group (CG). Participants in the CRG accomplished IMT at an exercise intensity of 60-90% of the maximum inspiratory pressure (MIP) with 30 breaths twice a day for 8 weeks, and those in the ARG performed IMT at an intensity of 40-50% of the MIP for approximately 20 min in the pre-training warm-up phase three times a week. Body composition tests, maximum oxygen uptake, anaerobic power tests, and lactate concentrations of participants were evaluated before and after the intervention. Three consecutive anaerobic power tests (Wingate) were performed to observe changes in lactate concentration and utilization during high-intensity exercises. Blood lactate concentrations were measured immediately at the end of each anaerobic power test, after a 75-s rest, and during passive rest at the 2nd, 3rd, 4th, 5th, 10th, and 15th min of recovery. The results of the analysis of variance (ANOVA) revealed a significant decrease in blood lactate concentration only in the CRG immediately after the first Wingate test, whereas significant differences in the ARG and the CG were observed after the third Wingate test. After the last Wingate test, a significant decrease was observed after 5 min of recovery in the CRG and after 10 and 15 min of passive rest in both training groups. Herein, we conclude that IMT decreases blood lactate concentration after intense exercise and accelerates lactate utilization during recovery.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"95 ","pages":"55-69"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11812165/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Habitual Running Style Matters: Duty Factor, and Not Stride Frequency, Relates to Loading Magnitude. 习惯性跑步方式很重要：负重系数，而非步频，与负荷大小有关。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-09-26 eCollection Date: 2024-10-01 DOI: 10.5114/jhk/191528

Lennert Van der Meulen, Senne Bonnaerens, Ine Van Caekenberghe, Dirk De Clercq, Veerle Segers, Pieter Fiers

{"title":"Habitual Running Style Matters: Duty Factor, and Not Stride Frequency, Relates to Loading Magnitude.","authors":"Lennert Van der Meulen, Senne Bonnaerens, Ine Van Caekenberghe, Dirk De Clercq, Veerle Segers, Pieter Fiers","doi":"10.5114/jhk/191528","DOIUrl":"10.5114/jhk/191528","url":null,"abstract":"Running style is temporally defined by a duty factor and stride frequency and believed to be related to the loading experienced during ever step. However, the exact relationship between both temporal variables and loading magnitude is still unknown. We aimed to identify the relationship between a duty factor and stride frequency with external load measures, joint reaction forces and joint moments. Thirty-one healthy female recreational runners ran across a 25-m runway at a speed of 2.30 ± 0.05 m·s-1. Ground reaction forces and motion capture data were used to determine the maximal vertical ground reaction force, the vertical instantaneous loading rate, peak braking force, peak joint extension moments and peak joint reaction forces at the knee and the ankle. The habitual duty factor and stride frequency of runners did not correlate with each other. The duty factor was found to be a significant predictor of maximal vertical ground reaction force (R2 = 0.585), peak braking force (R2 = 0.153), peak knee extension moment (R2 = 0.149), ankle plantar flexion moment (R2 = 0.225) and peak joint reaction forces at the knee (R2 = 0.591) and the ankle (R2 = 0.592), but not of the vertical instantaneous loading rate. Stride frequency had no significant predictive value. In conclusion, the maximal loading and potential injury risk of female recreational runners running with high duty factors are lower compared to those of peers running with lower duty factors.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"94 ","pages":"37-45"},"PeriodicalIF":1.9,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11571469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142675929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Increasing Braking and Amortization Forces during the Countermovement Jump Does Not Necessarily Improve Jump Height. 增加反向运动跳跃时的制动力和摊销力并不一定能提高跳跃高度。

IF 1.9 3区医学

Journal of Human Kinetics Pub Date : 2024-09-26 eCollection Date: 2024-10-01 DOI: 10.5114/jhk/190451

Daichi Nishiumi, Norikazu Hirose

{"title":"Increasing Braking and Amortization Forces during the Countermovement Jump Does Not Necessarily Improve Jump Height.","authors":"Daichi Nishiumi, Norikazu Hirose","doi":"10.5114/jhk/190451","DOIUrl":"10.5114/jhk/190451","url":null,"abstract":"This study aimed to investigate the acute effects of altering the braking rate of force development (B-RFD) and amortization force (Amf) during countermovement jumps (CMJs) on CMJ height. Nineteen healthy men and women with training experience participated, performing six CMJ variations at different velocities (preferred and fast) and depths (knee angles: 60°, 90°, and 120°). The measured variables included CMJ height, B-RFD, Amf, and impulses during the early and latter halves of the concentric phase (EI and LI, respectively). A two-way analysis of variance was employed, along with a correlational analysis of the rates of change for each variable. Significant velocity and depth effects were observed for B-RFD and Amf (p < 0.05). However, there was no significant velocity effect on CMJ height. No significant correlations were observed between the rates of change in B-RFD and Amf with CMJ height. Additionally, a high or a very high correlation (r ≥ 0.67) was observed between the rate of change in B-RFD and Amf with the rate of change in EI, while a moderate negative correlation (r = -0.43 to -0.53) was found between the rate of change in EI and LI. These findings suggest that improvements in B-RFD and Amf were associated with improvements in EI, while improvements in EI led to a reduction in LI, and consequently, improvements in B-RFD and Amf were not associated with an increase in CMJ height. In other words, improvements in B-RFD and Amf did not necessarily contribute to improvements in CMJ height.","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"94 ","pages":"65-75"},"PeriodicalIF":1.9,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11571463/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142675931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0