Mariusz Konieczny, Paweł Pakosz, Przemysław Domaszewski, Elżbieta Skorupska
BACKGROUND: In short track speed skating, there is asymmetric fatigue of the gluteus maximus (GM) muscle resulting from the technique of skating. Scientific reports confirm the relationship between muscle fatigue and its change in the slope frequency of bioelectrical activity. OBJECTIVE: To investigate whether athletic experience in elite short track speed skating can distinguish the asymmetry change in slope frequency of the raw electromyographic signal (EMG) of the GM muscle, influenced by the disparity in experience between junior and senior athletes. METHODS: In the research, an elite group of short track speed skating national team athletes Junior and Senior, participated. Isometric tension GM muscle was tested using the Biering-Sorensen test. RESULTS: The study confirmed differences in the asymmetry of slope frequences EMG signal in GM muscle between juniors and seniors in short track speed skating (p⩽ 0.001). Senior athletes showed greater slope frequences in the right GM muscle (p⩽ 0.002), while juniors showed greater in the left GM muscle (p⩽ 0.008). Intergroup analysis revealed significantly meaningful differences (p⩽ 0.001) in the level of slope frequences of the right GM muscle (juniors vs. seniors), highlighting the asymmetry resulting from experience. CONCLUSIONS: Statistically significant differences in the level of slope frequences of the right gluteus maximus muscle juniors vs. seniors were demonstrated, suggesting asymmetry due to experience and skating technique.
{"title":"The relationship between asymmetry changes in the slope frequency of bioelectrical activity of the gluteus maximus muscles and experience in short track speed skating athletics","authors":"Mariusz Konieczny, Paweł Pakosz, Przemysław Domaszewski, Elżbieta Skorupska","doi":"10.3233/ies-240004","DOIUrl":"https://doi.org/10.3233/ies-240004","url":null,"abstract":"BACKGROUND: In short track speed skating, there is asymmetric fatigue of the gluteus maximus (GM) muscle resulting from the technique of skating. Scientific reports confirm the relationship between muscle fatigue and its change in the slope frequency of bioelectrical activity. OBJECTIVE: To investigate whether athletic experience in elite short track speed skating can distinguish the asymmetry change in slope frequency of the raw electromyographic signal (EMG) of the GM muscle, influenced by the disparity in experience between junior and senior athletes. METHODS: In the research, an elite group of short track speed skating national team athletes Junior and Senior, participated. Isometric tension GM muscle was tested using the Biering-Sorensen test. RESULTS: The study confirmed differences in the asymmetry of slope frequences EMG signal in GM muscle between juniors and seniors in short track speed skating (p⩽ 0.001). Senior athletes showed greater slope frequences in the right GM muscle (p⩽ 0.002), while juniors showed greater in the left GM muscle (p⩽ 0.008). Intergroup analysis revealed significantly meaningful differences (p⩽ 0.001) in the level of slope frequences of the right GM muscle (juniors vs. seniors), highlighting the asymmetry resulting from experience. CONCLUSIONS: Statistically significant differences in the level of slope frequences of the right gluteus maximus muscle juniors vs. seniors were demonstrated, suggesting asymmetry due to experience and skating technique.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yukina Mochizuki, Takuto Naito, Sayaka Kikuchi, Hiroki Homma, Kathleen Y de Almeida, Naoki Kikuchi
BACKGROUND: The evidence of response to velocity loss cut-off training with similar total repetitions are limited. OBJECTIVE: This study aimed to examine the effects of different velocity loss training protocols after 3 weeks of traditional resistance training protocols on strength and power in trained men. METHODS: Twenty highly trained men participated in the study. The protocols were performed twice a week for 6-weeks, with the first 3-weeks consisting of traditional (TR) training protocols and the other 3-weeks of velocity loss (VL) training protocols. The TR and VL training protocols consisted of 80% 1RM of full squat exercise with 4-min rest intervals. The participants were randomly assigned to two different protocols during the VL training protocols, each with different velocity loss within sets (V20%; n= 10 or VL40%; n= 10). The number of sets was adjusted so that the total number of repetitions for each VL was similar (VL20 × 3 sets, VL40 × 2 sets). Measurements assessed using one-repetition maximum (1RM), isokinetic strength, 20 m-sprint (T20), and counter movement jump (CMJ). RESULTS: The total number of repetitions in the session significantly decreased from the TR training protocol to the VL training protocol in each group (TR to VL20; -18%, TR to VL40; -27%, p< 0.05). There was no significant difference of repetitions between groups. The T20 and isokinetic strength changed significantly in both groups after 6-weeks of training. CONCLUSION: The VL training protocol with reduced volume following the TR training protocol has been shown to maintain and increase strength and power outcomes. However, no significant difference in training response was observed between VL20 and VL40 protocols. The combination of TR and VL protocols might be an effective strategy for optimizing athletic performance.
{"title":"The effects of different velocity loss training protocols after 3 weeks of resistance training on muscular strength and power","authors":"Yukina Mochizuki, Takuto Naito, Sayaka Kikuchi, Hiroki Homma, Kathleen Y de Almeida, Naoki Kikuchi","doi":"10.3233/ies-240013","DOIUrl":"https://doi.org/10.3233/ies-240013","url":null,"abstract":"BACKGROUND: The evidence of response to velocity loss cut-off training with similar total repetitions are limited. OBJECTIVE: This study aimed to examine the effects of different velocity loss training protocols after 3 weeks of traditional resistance training protocols on strength and power in trained men. METHODS: Twenty highly trained men participated in the study. The protocols were performed twice a week for 6-weeks, with the first 3-weeks consisting of traditional (TR) training protocols and the other 3-weeks of velocity loss (VL) training protocols. The TR and VL training protocols consisted of 80% 1RM of full squat exercise with 4-min rest intervals. The participants were randomly assigned to two different protocols during the VL training protocols, each with different velocity loss within sets (V20%; n= 10 or VL40%; n= 10). The number of sets was adjusted so that the total number of repetitions for each VL was similar (VL20 × 3 sets, VL40 × 2 sets). Measurements assessed using one-repetition maximum (1RM), isokinetic strength, 20 m-sprint (T20), and counter movement jump (CMJ). RESULTS: The total number of repetitions in the session significantly decreased from the TR training protocol to the VL training protocol in each group (TR to VL20; -18%, TR to VL40; -27%, p< 0.05). There was no significant difference of repetitions between groups. The T20 and isokinetic strength changed significantly in both groups after 6-weeks of training. CONCLUSION: The VL training protocol with reduced volume following the TR training protocol has been shown to maintain and increase strength and power outcomes. However, no significant difference in training response was observed between VL20 and VL40 protocols. The combination of TR and VL protocols might be an effective strategy for optimizing athletic performance.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141832622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Özbay, Cebrail Gençoğlu, S. Ulupınar, Vedat Çınar, I. Ouergui, Dominik Hölbling
BACKGROUND: Based on recent research, slight performance differences, particularly dependent on the state of recovery, might be crucial for tournament success among elite-caliber kickboxers. OBJECTIVE: This study aims to; a) determine which strength-power tests could discriminate better between elite and top-elite kickboxers and, b) to evaluate changes in testing results between fatigued and well-rested athletes. METHODS: Twenty-two international kickboxers (including World and European Champions) volunteered to participate in this study. Nine kickboxers were assigned to the top-elite group and 13 to the elite group based on their highest tournament achievements. Subjects performed the Wingate test (Win) for anaerobic power; countermovement jump (CMJ) and squat jump (SJ) for neuromuscular power; push-ups and pull-ups for strength endurance; squats (SQ) and bench press (BP) for maximal dynamic strength; handgrip, leg, and back strength for isometric strength after full rest, following the fatigue and advanced fatigue protocols. RESULTS: Discriminant function analysis correctly classified the groups at 60.5%, 75.3%, and 86.3% in the resting, fatigue, and advanced fatigue protocols, respectively. Furthermore, all strength-power performances have significantly decreased and lactatepeak increased (p< 0.05) after the fatigue and advanced fatigue protocols in both groups. Significant interaction were also observed in the Winpeak (p< 0.001, ηp2= 0.559), Winmean (p= 0.009, ηp2= 0.246), CMJ (p= 0.010, ηp2= 0.273), push-ups (p< 0.001, ηp2= 0.389), SQabsolute (p= 0.001, ηp2= 0.337), BPabsolute (p= 0.014, ηp2= 0.235) and, Lactatepeak (p= 0.026, ηp2= 0.220). CONCLUSION: Resistance to fatigue may be the key component for distinguishing elite-level athletes. Thus, strength-power tests should be performed following a certain level of fatigue for the elite athletes due to distinguish them more effectively.
{"title":"The effect of fatigue on strength-power tests for distinguishing elite-level male kickboxers","authors":"S. Özbay, Cebrail Gençoğlu, S. Ulupınar, Vedat Çınar, I. Ouergui, Dominik Hölbling","doi":"10.3233/ies-240023","DOIUrl":"https://doi.org/10.3233/ies-240023","url":null,"abstract":"BACKGROUND: Based on recent research, slight performance differences, particularly dependent on the state of recovery, might be crucial for tournament success among elite-caliber kickboxers. OBJECTIVE: This study aims to; a) determine which strength-power tests could discriminate better between elite and top-elite kickboxers and, b) to evaluate changes in testing results between fatigued and well-rested athletes. METHODS: Twenty-two international kickboxers (including World and European Champions) volunteered to participate in this study. Nine kickboxers were assigned to the top-elite group and 13 to the elite group based on their highest tournament achievements. Subjects performed the Wingate test (Win) for anaerobic power; countermovement jump (CMJ) and squat jump (SJ) for neuromuscular power; push-ups and pull-ups for strength endurance; squats (SQ) and bench press (BP) for maximal dynamic strength; handgrip, leg, and back strength for isometric strength after full rest, following the fatigue and advanced fatigue protocols. RESULTS: Discriminant function analysis correctly classified the groups at 60.5%, 75.3%, and 86.3% in the resting, fatigue, and advanced fatigue protocols, respectively. Furthermore, all strength-power performances have significantly decreased and lactatepeak increased (p< 0.05) after the fatigue and advanced fatigue protocols in both groups. Significant interaction were also observed in the Winpeak (p< 0.001, ηp2= 0.559), Winmean (p= 0.009, ηp2= 0.246), CMJ (p= 0.010, ηp2= 0.273), push-ups (p< 0.001, ηp2= 0.389), SQabsolute (p= 0.001, ηp2= 0.337), BPabsolute (p= 0.014, ηp2= 0.235) and, Lactatepeak (p= 0.026, ηp2= 0.220). CONCLUSION: Resistance to fatigue may be the key component for distinguishing elite-level athletes. Thus, strength-power tests should be performed following a certain level of fatigue for the elite athletes due to distinguish them more effectively.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141832058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BACKGROUND: Warm-up exercises are often recommended to enhance flexibility, reduce the risk of injury, and improve performance. However, the optimal number of warm-up repetitions remains unclear. Additionally, the previously suggested sit-and-reach test may not be suitable for efficiently stimulating the target muscles. OBJECTIVE: This study investigated the effects of a warm-up consisting of 15 straight leg raise (SLR) repetitions on hip and knee flexibility by comparing individuals with and without hamstring tightness (HT and NoHT, respectively). METHODS: Thirty healthy adults were classified as having HT or NoHT based on their SLR angle before warm-up. The participants performed 15 repetitions of the SLR as warm-up, followed by hip and knee flexibility tests. RESULTS: Warm-ups significantly improved hip and knee flexibility in both HT and NoHT groups. Improvements in flexibility were not significantly different between groups. The most notable increase in flexibility was observed between the sixth and ninth SLR trials. CONCLUSIONS: The clinical utility of a warm-up consisting of 15 SLR repetitions is supported by this study, as a substantial increase in hip flexibility was observed in all participants regardless of HT. In clinical settings, a maximum of 10 repetitions may be sufficient to achieve optimal results.
{"title":"Optimizing warm-up efficiency: Impact of repetitions in straight leg raises on hip and knee flexibility in individuals with and without hamstring tightness","authors":"Wootaek Lim","doi":"10.3233/ies-240049","DOIUrl":"https://doi.org/10.3233/ies-240049","url":null,"abstract":"BACKGROUND: Warm-up exercises are often recommended to enhance flexibility, reduce the risk of injury, and improve performance. However, the optimal number of warm-up repetitions remains unclear. Additionally, the previously suggested sit-and-reach test may not be suitable for efficiently stimulating the target muscles. OBJECTIVE: This study investigated the effects of a warm-up consisting of 15 straight leg raise (SLR) repetitions on hip and knee flexibility by comparing individuals with and without hamstring tightness (HT and NoHT, respectively). METHODS: Thirty healthy adults were classified as having HT or NoHT based on their SLR angle before warm-up. The participants performed 15 repetitions of the SLR as warm-up, followed by hip and knee flexibility tests. RESULTS: Warm-ups significantly improved hip and knee flexibility in both HT and NoHT groups. Improvements in flexibility were not significantly different between groups. The most notable increase in flexibility was observed between the sixth and ninth SLR trials. CONCLUSIONS: The clinical utility of a warm-up consisting of 15 SLR repetitions is supported by this study, as a substantial increase in hip flexibility was observed in all participants regardless of HT. In clinical settings, a maximum of 10 repetitions may be sufficient to achieve optimal results.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BACKGROUND: Low muscle quantity commonly seen in patients undergoing hemodialysis (HD) is the key contributor of declined physical performance and increases the risk of morbidity and mortality. However, how to normalize muscle mass for operational criteria in this population remains unknown. OBJECTIVE: To identify the clinically useful whole body lean tissue mass (LTM) and appendicular skeletal muscle mass (ASM) indices pertinent to physical performance in patients undertaking HD. METHODS: Whole body LTM in 38 and ASM in 22 patients undergoing HD were measured by body composition monitor (BCM) and dual-energy X-ray absorptiometry (DXA), respectively. Physical performance was assessed by handgrip strength, the incremental shuttle walk test, sit-to-stand tests, gait speed, Short Physical Performance Battery and Duke Activity Status Index. Besides crude LTM and ASM, the other muscle indices were utilized normalizing for height, height squared, weight, body mass index (BMI), fat mass and body fat%. RESULTS: Regardless of BCM or DXA being used, the relationships between different muscle mass indices and physical function were not consistent. While the most useful LTM index which was strongly associated with physical function involved adjustment for height, the strongest (and most useful) ASM index was normalization for BMI. CONCLUSION: The superiority of adjustment for BMI or height (height2) recommended by international sarcopenia consensus is also suitable for patients undergoing HD. Patients’ BMI or fat mass should be considered in estimating prevalence of sarcopenia and evaluating relationship between muscle mass and physical performance.
背景：血液透析（HD）患者中常见的低肌肉量是导致体能下降的主要原因，并增加了发病和死亡的风险。然而，如何使这一人群的肌肉质量符合操作标准仍是未知数。目的：确定与血液透析患者体能表现相关的、对临床有用的全身瘦肉组织质量（LTM）和附属骨骼肌质量（ASM）指数。方法：通过身体成分监测仪（BCM）和双能 X 射线吸收测量仪（DXA）分别测量了 38 名接受血液透析患者的全身瘦肉组织质量（LTM）和 22 名接受血液透析患者的骨骼肌质量（ASM）。体能通过手握强度、增量穿梭步行测试、坐立测试、步速、短期体能测试和杜克活动状态指数进行评估。除了粗LTM和ASM外，其他肌肉指数也根据身高、身高平方、体重、体重指数（BMI）、脂肪量和体脂率进行了归一化处理。结果：无论使用 BCM 还是 DXA，不同肌肉质量指数与身体功能之间的关系并不一致。与身体功能密切相关的最有用的 LTM 指数涉及身高调整，而最强（也是最有用）的 ASM 指数是体重指数正常化。结论：国际肌肉疏松症共识推荐的调整体重指数或身高（身高2）的优越性也适用于接受 HD 治疗的患者。在估计肌肉疏松症的患病率及评估肌肉质量与体能表现之间的关系时，应考虑患者的体重指数或脂肪量。
{"title":"The useful lean tissue and appendicular skeletal muscle mass indices related to physical performance in patients undergoing hemodialysis","authors":"Yan Song, Xuanrui Zhang, Jianxia Lu","doi":"10.3233/ies-230142","DOIUrl":"https://doi.org/10.3233/ies-230142","url":null,"abstract":"BACKGROUND: Low muscle quantity commonly seen in patients undergoing hemodialysis (HD) is the key contributor of declined physical performance and increases the risk of morbidity and mortality. However, how to normalize muscle mass for operational criteria in this population remains unknown. OBJECTIVE: To identify the clinically useful whole body lean tissue mass (LTM) and appendicular skeletal muscle mass (ASM) indices pertinent to physical performance in patients undertaking HD. METHODS: Whole body LTM in 38 and ASM in 22 patients undergoing HD were measured by body composition monitor (BCM) and dual-energy X-ray absorptiometry (DXA), respectively. Physical performance was assessed by handgrip strength, the incremental shuttle walk test, sit-to-stand tests, gait speed, Short Physical Performance Battery and Duke Activity Status Index. Besides crude LTM and ASM, the other muscle indices were utilized normalizing for height, height squared, weight, body mass index (BMI), fat mass and body fat%. RESULTS: Regardless of BCM or DXA being used, the relationships between different muscle mass indices and physical function were not consistent. While the most useful LTM index which was strongly associated with physical function involved adjustment for height, the strongest (and most useful) ASM index was normalization for BMI. CONCLUSION: The superiority of adjustment for BMI or height (height2) recommended by international sarcopenia consensus is also suitable for patients undergoing HD. Patients’ BMI or fat mass should be considered in estimating prevalence of sarcopenia and evaluating relationship between muscle mass and physical performance.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Stotz, Steven Richter, Joel Mason, Astrid Zech
BACKGROUND: It has been demonstrated that maximum isometric muscle moment can surpass maximum eccentric muscle moment at individually adjusted joint angles in men. However, no information about these muscle mechanics is available for women. OBJECTIVE: To examine the maximum muscle moment hierarchywith equal conditions in women. METHODS: Maximum voluntary concentric, eccentric, and isometric muscle moments of ankle, knee, and hip flexors and extensors as well as hip adductors and abductors were tested in eighteen young women. The sequence of muscle group testing was the same for all subjects, and the sequence of contraction types was randomized. All dynamic contractions were performed at 60∘/s. Peak moment angle of concentric contractions was applied for isometric moment testing. A repeated measures ANOVA with posthoc Bonferroni correction was used to compare means between contraction types. RESULTS: Differences in maximum moment mean values between the three contraction types were apparent for all muscle groups (p< 0.001). Concentric muscle moment was significantly the weakest contraction type. Eccentric contractions generated significantly higher moments than isometric contractions in dorsiflexion, plantarflexion, knee flexion, and hip adduction. CONCLUSION: Significant differences in maximum lower body muscle moments exist between concentric, eccentric, and isometric contractions in women. Compared to previous research for men there appears to be a sex-specific contraction type hierarchy with women exhibiting superior ability to generate higher eccentric muscle moment relative to other contraction types. These results should be considered when designing contractiontype specific intervention programs.
{"title":"Peak moments of lower extremity muscles in women: A comparative study of concentric, eccentric and isometric contractions","authors":"Andreas Stotz, Steven Richter, Joel Mason, Astrid Zech","doi":"10.3233/ies-240031","DOIUrl":"https://doi.org/10.3233/ies-240031","url":null,"abstract":"BACKGROUND: It has been demonstrated that maximum isometric muscle moment can surpass maximum eccentric muscle moment at individually adjusted joint angles in men. However, no information about these muscle mechanics is available for women. OBJECTIVE: To examine the maximum muscle moment hierarchywith equal conditions in women. METHODS: Maximum voluntary concentric, eccentric, and isometric muscle moments of ankle, knee, and hip flexors and extensors as well as hip adductors and abductors were tested in eighteen young women. The sequence of muscle group testing was the same for all subjects, and the sequence of contraction types was randomized. All dynamic contractions were performed at 60∘/s. Peak moment angle of concentric contractions was applied for isometric moment testing. A repeated measures ANOVA with posthoc Bonferroni correction was used to compare means between contraction types. RESULTS: Differences in maximum moment mean values between the three contraction types were apparent for all muscle groups (p< 0.001). Concentric muscle moment was significantly the weakest contraction type. Eccentric contractions generated significantly higher moments than isometric contractions in dorsiflexion, plantarflexion, knee flexion, and hip adduction. CONCLUSION: Significant differences in maximum lower body muscle moments exist between concentric, eccentric, and isometric contractions in women. Compared to previous research for men there appears to be a sex-specific contraction type hierarchy with women exhibiting superior ability to generate higher eccentric muscle moment relative to other contraction types. These results should be considered when designing contractiontype specific intervention programs.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141573472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BACKGROUND: Patellar tendinopathy (PT) is a common injury involving inadequate eccentric (ECC) knee extensor contractions during dynamic sports activities. However, any discrepancies in ECC power output between Olympic athletes with and without PT utilizing a flywheel ergometer squat remain to be determined. OBJECTIVE: To compare peak ECC power, concentric (CON) power, the ECC/CON power ratio, and performance speed in female and male athletes with and without PT, respectively. METHODS: Forty Olympic athletes with and without PT were included and analyzed for ECC power, CON power, ECC/CON power ratio, and performance speed (m/s) under varying load conditions, with analyses separated by gender. RESULTS: The ECC power, ECC/CON power ratio, and performance speed of the PT group were significantly lower than those of the non-PT (NPT) group in both genders. ECC and CON power significantly increased with higher inertial loads in the NPT groups, whereas the speed significantly decreased as the inertial load increased in both PT and NPT groups. CONCLUSIONS: Dynamic flywheel ergometer assessments may help in the quantitative diagnosis of athletes with PT under differing dynamic squat conditions. This assessment may be used to create standardized guidelines for squat performance testing, strengthening, conditioning, and rehabilitation.
{"title":"Ecologically dynamic flywheel ergometer squat performance characteristics between national Olympic athletes with and without patellar tendinopathy","authors":"Hyoungjoo Choi, Joshua (Sung) H. You","doi":"10.3233/ies-230176","DOIUrl":"https://doi.org/10.3233/ies-230176","url":null,"abstract":"BACKGROUND: Patellar tendinopathy (PT) is a common injury involving inadequate eccentric (ECC) knee extensor contractions during dynamic sports activities. However, any discrepancies in ECC power output between Olympic athletes with and without PT utilizing a flywheel ergometer squat remain to be determined. OBJECTIVE: To compare peak ECC power, concentric (CON) power, the ECC/CON power ratio, and performance speed in female and male athletes with and without PT, respectively. METHODS: Forty Olympic athletes with and without PT were included and analyzed for ECC power, CON power, ECC/CON power ratio, and performance speed (m/s) under varying load conditions, with analyses separated by gender. RESULTS: The ECC power, ECC/CON power ratio, and performance speed of the PT group were significantly lower than those of the non-PT (NPT) group in both genders. ECC and CON power significantly increased with higher inertial loads in the NPT groups, whereas the speed significantly decreased as the inertial load increased in both PT and NPT groups. CONCLUSIONS: Dynamic flywheel ergometer assessments may help in the quantitative diagnosis of athletes with PT under differing dynamic squat conditions. This assessment may be used to create standardized guidelines for squat performance testing, strengthening, conditioning, and rehabilitation.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BACKGROUND: Hip flexion angle-moment may not be measured accurately due to the measurement posture. OBJECTIVE: Maximum isometric hip flexion moment was measured while excluding the effects of postural retention function and compensatory motion. METHODS: Experiment 1: Maximum isometric flexion moment of the hip joint was measured at 0∘, 30∘, 60∘, 90∘, and 105∘ in 195 participants. Experiment 2: Maximum isometric hip flexion moment of 33 participants was measured in standing and supine position at 0∘ hip flexion and in end-sitting and supine position at 105∘. RESULTS: Experiment 1: No interaction was observed between sex and hip angle, and hip flexion moment was minimum at 0∘ hip flexion and maximum at 105∘ hip flexion in both sexes (p< 0.01). Experiment 2: An interaction between measurement position and hip angle was observed, with maximum isometric flexion moment being greater in the supine position than in the standing position (p< 0.01). Maximum isometric hip flexion moment was greater at 105∘ than at 0∘ flexion (p< 0.01). CONCLUSIONS: Maximum isometric hip flexion moment showed greater joint angle-moment characteristics in deep flexion than in shallow flexion of the hip when excluding the effects of postural retention function and compensatory motion.
{"title":"Re-examination of hip flexion angle-moment characteristics","authors":"Kazuhiro Ito, Etsuko Maeshima, Koichi Saito, H. Koshiba, Takaaki Nakamata, Kazuki Yamaguchi, Ryota Maegawa, Yasuhiko Hatanaka","doi":"10.3233/ies-240003","DOIUrl":"https://doi.org/10.3233/ies-240003","url":null,"abstract":"BACKGROUND: Hip flexion angle-moment may not be measured accurately due to the measurement posture. OBJECTIVE: Maximum isometric hip flexion moment was measured while excluding the effects of postural retention function and compensatory motion. METHODS: Experiment 1: Maximum isometric flexion moment of the hip joint was measured at 0∘, 30∘, 60∘, 90∘, and 105∘ in 195 participants. Experiment 2: Maximum isometric hip flexion moment of 33 participants was measured in standing and supine position at 0∘ hip flexion and in end-sitting and supine position at 105∘. RESULTS: Experiment 1: No interaction was observed between sex and hip angle, and hip flexion moment was minimum at 0∘ hip flexion and maximum at 105∘ hip flexion in both sexes (p< 0.01). Experiment 2: An interaction between measurement position and hip angle was observed, with maximum isometric flexion moment being greater in the supine position than in the standing position (p< 0.01). Maximum isometric hip flexion moment was greater at 105∘ than at 0∘ flexion (p< 0.01). CONCLUSIONS: Maximum isometric hip flexion moment showed greater joint angle-moment characteristics in deep flexion than in shallow flexion of the hip when excluding the effects of postural retention function and compensatory motion.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141389379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andy Waldhelm, Lauren McElroy, Cameron Buescher, Haley Barnett, Jessica Cunningham, Jared Richards, Neal Schwarz
BACKGROUND: Test selection during the return to sport evaluation is an important aspect of ensuring athletes are safe to return to competition. OBJECTIVE: To assess the test-retest and inter-rater reliability of two new single leg hamstring bridge tests (SLHBT) and the relationships between these new tests and isokinetic strength of the quadriceps and hamstrings. METHODS: Thirty healthy college students completed the study. Two testing sessions were held three to seven days apart. Session one, participants performed two SLHBT as well as concentric isokinetic strength tests for the hamstring and quadriceps at 60, 180 and 300∘/sec. The participants performed only the two SLHBT during the second session. The first SLHBT, participants performed as many repetitions as possible of the SLHBT in 30-sec, while the second test measured how quickly the participants could perform five repetitions. Intraclass Correlation Coefficients (ICC2,1) were used to assess test-retest reliability while ICC(3,1) were used to test inter-rater reliability. RESULTS: The test-retest reliability for the SLHBTs was moderate to good, with ICC(2,1) ranging from 0.68 to 0.75, while the inter-rater reliability were excellent with ICC(3,1) all above 0.98. There were significant correlations between the SLHBT and the isokinetic tests, but all correlations were low to moderate. CONCLUSION: This study found good to excellent reliability with the new SLHBT and poor to moderate correlations were noted Therefore, SLHBT may not be an alternative to test hamstring test during the RTS evaluation due to the multiple compensatory strategies athletes may have.
{"title":"Reliability of two new single leg hamstring bridge tests and comparison to isokinetic strength tests","authors":"Andy Waldhelm, Lauren McElroy, Cameron Buescher, Haley Barnett, Jessica Cunningham, Jared Richards, Neal Schwarz","doi":"10.3233/ies-230084","DOIUrl":"https://doi.org/10.3233/ies-230084","url":null,"abstract":"BACKGROUND: Test selection during the return to sport evaluation is an important aspect of ensuring athletes are safe to return to competition. OBJECTIVE: To assess the test-retest and inter-rater reliability of two new single leg hamstring bridge tests (SLHBT) and the relationships between these new tests and isokinetic strength of the quadriceps and hamstrings. METHODS: Thirty healthy college students completed the study. Two testing sessions were held three to seven days apart. Session one, participants performed two SLHBT as well as concentric isokinetic strength tests for the hamstring and quadriceps at 60, 180 and 300∘/sec. The participants performed only the two SLHBT during the second session. The first SLHBT, participants performed as many repetitions as possible of the SLHBT in 30-sec, while the second test measured how quickly the participants could perform five repetitions. Intraclass Correlation Coefficients (ICC2,1) were used to assess test-retest reliability while ICC(3,1) were used to test inter-rater reliability. RESULTS: The test-retest reliability for the SLHBTs was moderate to good, with ICC(2,1) ranging from 0.68 to 0.75, while the inter-rater reliability were excellent with ICC(3,1) all above 0.98. There were significant correlations between the SLHBT and the isokinetic tests, but all correlations were low to moderate. CONCLUSION: This study found good to excellent reliability with the new SLHBT and poor to moderate correlations were noted Therefore, SLHBT may not be an alternative to test hamstring test during the RTS evaluation due to the multiple compensatory strategies athletes may have.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141389212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BACKGROUND: Maca extract may regulate oxidative stress and muscle damage after exhaustive endurance exercise (EEE); however, its impact on these physiological activities remains obscure. OBJECTIVE: To examine the effects of Maca extract supplementation on oxidative stress, muscle damage and aerobiccapacity after EEE. METHODS: Twenty healthy men were assigned to Maca or placebo groups and received two doses per day for 12 weeks. Pre- and post-EEE tests assessed levels of oxidative stress and muscle damage. The EEE test also recorded metrics such as time to exhaustion, peak oxygen consumption, and maximal and average heart rates. RESULTS: Post-exercise, there was no significant difference in oxidative stress markers between the Maca and placebo groups. However, the Maca group exhibited lower stress levels at both Post-4 and Post-24 in comparison to Post-0, while the placebo group only displayed a decrease at Post-4. Notably, Maca extract supplementation immediately increased catalase activity at Post-0. Though muscle damage markers did not significantly differ, the slope of CK elevation in the Maca group appeared lower than the Placebo group, suggesting Maca’s potential in preventing muscle damage. However, no differences were noted on aerobic capacity markers. CONCLUSIONS: Maca extract may have some beneficial effects on reducing oxidative stress and possibly muscle damage after EEE.
{"title":"Effects of lepidium meyenii (Maca) extract supplementation on oxidative stress, muscle damage, and aerobic capacity after exhaustive endurance exercise","authors":"Ming-Che Liu, Pei-Wei Weng, Yu-Hsiu Chien, Meng-Huang Wu, Wei-Bin Hsu, Sheng-Wei Chen, Ming-Ta Yang","doi":"10.3233/ies-240006","DOIUrl":"https://doi.org/10.3233/ies-240006","url":null,"abstract":"BACKGROUND: Maca extract may regulate oxidative stress and muscle damage after exhaustive endurance exercise (EEE); however, its impact on these physiological activities remains obscure. OBJECTIVE: To examine the effects of Maca extract supplementation on oxidative stress, muscle damage and aerobiccapacity after EEE. METHODS: Twenty healthy men were assigned to Maca or placebo groups and received two doses per day for 12 weeks. Pre- and post-EEE tests assessed levels of oxidative stress and muscle damage. The EEE test also recorded metrics such as time to exhaustion, peak oxygen consumption, and maximal and average heart rates. RESULTS: Post-exercise, there was no significant difference in oxidative stress markers between the Maca and placebo groups. However, the Maca group exhibited lower stress levels at both Post-4 and Post-24 in comparison to Post-0, while the placebo group only displayed a decrease at Post-4. Notably, Maca extract supplementation immediately increased catalase activity at Post-0. Though muscle damage markers did not significantly differ, the slope of CK elevation in the Maca group appeared lower than the Placebo group, suggesting Maca’s potential in preventing muscle damage. However, no differences were noted on aerobic capacity markers. CONCLUSIONS: Maca extract may have some beneficial effects on reducing oxidative stress and possibly muscle damage after EEE.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141172119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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