This study aimed to investigate the regularity of the lower limb joint kinematics in runners with and without a history of running-related injuries. The second aim was to verify if the movement pattern regularities are different among the lower limb joints. Eighteen asymptomatic recreational runners with and without a history of running-related injury participated in this study. Lower limb kinematics in the sagittal plane were recorded during running on a treadmill at a self-selected speed. The regularities of the time series of hip, knee, and ankle were analysed using sample entropy (SampEn). A mixed analysis of variance was used to investigate differences between groups and among joints. Runners with a history of injury had lower SampEn values than runners without a history of injury. Ankle kinematics SampEn was higher than that of the knee and hip. Knee kinematics had higher values of SampEn than that of the hip. Runners with a history of running-related injury had greater joint kinematic's regularity. This result suggests that, even in asymptomatic runners, previous injuries could influence the movement pattern regularity. Also, the regularity was different among joints. The ankle demonstrated the lowest regularity, reinforcing the different functions that lower limb joints perform during running.
{"title":"Runners with a history of injury have greater lower limb movement regularity than runners without a history of injury.","authors":"Juliana Quirino, Thiago Ribeiro Teles Santos, Liria Akie Okai-Nóbrega, Priscila Albuquerque de Araújo, Renatha Carvalho, Juliana de Melo Ocarino, Thales Rezende Souza, Sérgio Teixeira Fonseca","doi":"10.1080/14763141.2021.1929435","DOIUrl":"10.1080/14763141.2021.1929435","url":null,"abstract":"<p><p>This study aimed to investigate the regularity of the lower limb joint kinematics in runners with and without a history of running-related injuries. The second aim was to verify if the movement pattern regularities are different among the lower limb joints. Eighteen asymptomatic recreational runners with and without a history of running-related injury participated in this study. Lower limb kinematics in the sagittal plane were recorded during running on a treadmill at a self-selected speed. The regularities of the time series of hip, knee, and ankle were analysed using sample entropy (SampEn). A mixed analysis of variance was used to investigate differences between groups and among joints. Runners with a history of injury had lower SampEn values than runners without a history of injury. Ankle kinematics SampEn was higher than that of the knee and hip. Knee kinematics had higher values of SampEn than that of the hip. Runners with a history of running-related injury had greater joint kinematic's regularity. This result suggests that, even in asymptomatic runners, previous injuries could influence the movement pattern regularity. Also, the regularity was different among joints. The ankle demonstrated the lowest regularity, reinforcing the different functions that lower limb joints perform during running.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39088646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2021-07-13DOI: 10.1080/14763141.2021.1942540
Samuel J Callaghan, Robert G Lockie, Jamie Tallent, Robert F Chipchase, Warren A Andrews, Sophia Nimphius
The effects of an eight-week off-season strength training program upon lower-body strength, power, eccentric capacity, front foot contact (FFC) kinetics, and ball release speed (BRS) in pace bowlers were investigated. Ten elite-academy pace bowlers completed the intervention, and pre- and post-testing. Pre- and post-testing included: double (DLDL) and single leg (SLDL) drop landings; isometric mid-thigh pull (IMTP); countermovement jump; and pace bowling performance (two-over bowling spell measuring BRS and FFC kinetics). Changes from pre- to post-testing were assessed with paired sample t tests (p≤ 0.01), effects sizes and statistical parametrical mapping. Post-testing revealed a significant decrease in peak normalised vertical force during DLDL and SLDL with large effects and a significant, moderate effect increase in IMTP. There was no significant changes in BRS. Concomitantly, neither discrete scalar (p= 0.15-0.58) nor vector field analysis kinetics during FFC indicated significant changes. No significant alterations in FFC kinetics may explain the lack of improvement in BRS (pre = 31.55 ± 1.44 m/s; post = 31.79 ± 1.33 m/s). This study indicated an eight-week strength training program can improve strength and eccentric capacity in pace bowlers, and these changes when developed in the absence of skills training neither improved nor decreased pace bowling performance.
{"title":"The effects of strength training upon front foot contact ground reaction forces and ball release speed among high-level cricket pace bowlers.","authors":"Samuel J Callaghan, Robert G Lockie, Jamie Tallent, Robert F Chipchase, Warren A Andrews, Sophia Nimphius","doi":"10.1080/14763141.2021.1942540","DOIUrl":"10.1080/14763141.2021.1942540","url":null,"abstract":"<p><p>The effects of an eight-week off-season strength training program upon lower-body strength, power, eccentric capacity, front foot contact (FFC) kinetics, and ball release speed (BRS) in pace bowlers were investigated. Ten elite-academy pace bowlers completed the intervention, and pre- and post-testing. Pre- and post-testing included: double (DLDL) and single leg (SLDL) drop landings; isometric mid-thigh pull (IMTP); countermovement jump; and pace bowling performance (two-over bowling spell measuring BRS and FFC kinetics). Changes from pre- to post-testing were assessed with paired sample t tests (p≤ 0.01), effects sizes and statistical parametrical mapping. Post-testing revealed a significant decrease in peak normalised vertical force during DLDL and SLDL with large effects and a significant, moderate effect increase in IMTP. There was no significant changes in BRS. Concomitantly, neither discrete scalar (p= 0.15-0.58) nor vector field analysis kinetics during FFC indicated significant changes. No significant alterations in FFC kinetics may explain the lack of improvement in BRS (pre = 31.55 ± 1.44 m/s; post = 31.79 ± 1.33 m/s). This study indicated an eight-week strength training program can improve strength and eccentric capacity in pace bowlers, and these changes when developed in the absence of skills training neither improved nor decreased pace bowling performance.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39179063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2021-05-19DOI: 10.1080/14763141.2021.1927162
Gen Horiuchi, Hirotaka Nakashima, Shinji Sakurai
The purpose of this study was to clarify the relationship between the efficiency of mechanical energy flow in the torso and bat head speed at impact. Ninety-eight amateur baseball players batted a light ball tossed from the pitcher direction 3.2 m away. The batting motion and ground reaction forces acting on each foot were recorded using a motion capture system and two force plates, respectively. The mechanical powers of the joint forces and joint torques were calculated to measure the generation, absorption, and transfer of mechanical energy in the torso. The transfer efficiency of mechanical energy in the torso was defined as the ratio of the mechanical energy inflow into the thorax from the torso joint to the mechanical energy outflow from the pelvis to the torso joint. The correlation coefficient between the bat head speed and transfer efficiency of mechanical energy in the torso was very low. Conversely, the mechanical energy flow in the torso was significantly correlated to the bat head speed. Therefore, the results suggest that the torso in baseball batting is not utilised for the generation of mechanical energy but acts as a pathway for the transfer of mechanical energy.
{"title":"Mechanical energy flow in torso during baseball toss batting.","authors":"Gen Horiuchi, Hirotaka Nakashima, Shinji Sakurai","doi":"10.1080/14763141.2021.1927162","DOIUrl":"10.1080/14763141.2021.1927162","url":null,"abstract":"<p><p>The purpose of this study was to clarify the relationship between the efficiency of mechanical energy flow in the torso and bat head speed at impact. Ninety-eight amateur baseball players batted a light ball tossed from the pitcher direction 3.2 m away. The batting motion and ground reaction forces acting on each foot were recorded using a motion capture system and two force plates, respectively. The mechanical powers of the joint forces and joint torques were calculated to measure the generation, absorption, and transfer of mechanical energy in the torso. The transfer efficiency of mechanical energy in the torso was defined as the ratio of the mechanical energy inflow into the thorax from the torso joint to the mechanical energy outflow from the pelvis to the torso joint. The correlation coefficient between the bat head speed and transfer efficiency of mechanical energy in the torso was very low. Conversely, the mechanical energy flow in the torso was significantly correlated to the bat head speed. Therefore, the results suggest that the torso in baseball batting is not utilised for the generation of mechanical energy but acts as a pathway for the transfer of mechanical energy.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38927686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2021-06-14DOI: 10.1080/14763141.2021.1925732
Elham Hosseini, Abdolhamid Daneshjoo, Mansour Sahebozamani, David Behm
This study was aimed to compare the knee kinematic parameters between dominant and non-dominant legs of adolescent female athletes during change of direction (CoD) in fatigued and unpredictable settings. Knee kinematic parameters on 49 athletes (mean± SD; age = 14.69 ± 0.14 years; mass = 49.05 ± 1.22 kg; height = 1.61 ± 0.08 m) during CoD before and after performing the Bruce protocol and also in predictable and unpredictable setting situations were collected. Kinematic data were recorded at a sampling rate of 200 Hz. The results showed that the dominant leg had significantly 18.7% more flexion (p = 0.001, η = 0.95), 7.1% less valgus (p = 0.001, η = 0.95) and 0.32% lower tibia rotation (p = 0.003, η = 0.16) compared to the non-dominant leg in predictable and pre-fatigue (p < 0.05) conditions. With unpredictable and post-fatigue conditions the dominant limb again demonstrated 17.4% (p = 0.001, η = 0.67), greater knee flexion, 6.8% (0.003,η = 0.97) lower knee valgus and 1.4% (p = 0.001, η = 0.71) less tibiarotation. In conclusion, there may be an increased risk of injury withthe non-dominant leg due to changes in kinematic parameters caused by fatigue and unpredictable CoD manoeuvres.
{"title":"The effects of fatigue on knee kinematics during unanticipated change of direction in adolescent girl athletes: a comparison between dominant and non-dominant legs.","authors":"Elham Hosseini, Abdolhamid Daneshjoo, Mansour Sahebozamani, David Behm","doi":"10.1080/14763141.2021.1925732","DOIUrl":"10.1080/14763141.2021.1925732","url":null,"abstract":"<p><p>This study was aimed to compare the knee kinematic parameters between dominant and non-dominant legs of adolescent female athletes during change of direction (CoD) in fatigued and unpredictable settings. Knee kinematic parameters on 49 athletes (mean± SD; age = 14.69 ± 0.14 years; mass = 49.05 ± 1.22 kg; height = 1.61 ± 0.08 m) during CoD before and after performing the Bruce protocol and also in predictable and unpredictable setting situations were collected. Kinematic data were recorded at a sampling rate of 200 Hz. The results showed that the dominant leg had significantly 18.7% more flexion (p = 0.001, η = 0.95), 7.1% less valgus (p = 0.001, η = 0.95) and 0.32% lower tibia rotation (p = 0.003, η = 0.16) compared to the non-dominant leg in predictable and pre-fatigue (p < 0.05) conditions. With unpredictable and post-fatigue conditions the dominant limb again demonstrated 17.4% (p = 0.001, η = 0.67), greater knee flexion, 6.8% (0.003,η = 0.97) lower knee valgus and 1.4% (p = 0.001, η = 0.71) less tibiarotation. In conclusion, there may be an increased risk of injury withthe non-dominant leg due to changes in kinematic parameters caused by fatigue and unpredictable CoD manoeuvres.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39088643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2021-06-03DOI: 10.1080/14763141.2021.1923793
Daniel A Marinho, Dennis Willemsen, Tiago M Barbosa, António José Silva, J Paulo Vilas-Boas, Henrique P Neiva, Pedro Forte
The aim of this study was to analyse the effect of swimming goggles on swimming hydrodynamics by numerical simulations. An elite swimmer volunteered for this research. The swimmer's head was scanned both without goggles, and while wearing 3 different types of goggles (Nikko, Ankor and Swedish). Numerical simulations were conducted at 2 m/s with the Fluent code. The condition without goggles showed the highest viscous drag (1.65 N), followed by the Ankor (1.64 N), Swedish (1.63 N) and Nikko (1.62 N) goggles, respectively. The highest pressure drag was found in the situation without goggles (11.34 N), followed by the Ankor (10.87 N), Nikko (10.78 N) and Swedish (10.20 N) goggles. The condition without goggles presented the highest total drag (12.99 N), followed by the Ankor (12.52 N), Nikko (12.40 N) and Swedish (11.83 N) goggles. Thus, Swedish goggles yields the best hydrodynamics, followed by the Nikko and Ankor goggles and lastly without goggles. Thus, goggles minimise the swimmer's drag comparing to not wearing any. The design of the goggles may impose varying drag forces and therefore it is advised to use goggles at least in competition.
{"title":"Numerical simulations of a swimmer's head and cap wearing different types of goggles.","authors":"Daniel A Marinho, Dennis Willemsen, Tiago M Barbosa, António José Silva, J Paulo Vilas-Boas, Henrique P Neiva, Pedro Forte","doi":"10.1080/14763141.2021.1923793","DOIUrl":"10.1080/14763141.2021.1923793","url":null,"abstract":"<p><p>The aim of this study was to analyse the effect of swimming goggles on swimming hydrodynamics by numerical simulations. An elite swimmer volunteered for this research. The swimmer's head was scanned both without goggles, and while wearing 3 different types of goggles (Nikko, Ankor and Swedish). Numerical simulations were conducted at 2 m/s with the Fluent code. The condition without goggles showed the highest viscous drag (1.65 N), followed by the Ankor (1.64 N), Swedish (1.63 N) and Nikko (1.62 N) goggles, respectively. The highest pressure drag was found in the situation without goggles (11.34 N), followed by the Ankor (10.87 N), Nikko (10.78 N) and Swedish (10.20 N) goggles. The condition without goggles presented the highest total drag (12.99 N), followed by the Ankor (12.52 N), Nikko (12.40 N) and Swedish (11.83 N) goggles. Thus, Swedish goggles yields the best hydrodynamics, followed by the Nikko and Ankor goggles and lastly without goggles. Thus, goggles minimise the swimmer's drag comparing to not wearing any. The design of the goggles may impose varying drag forces and therefore it is advised to use goggles at least in competition.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39056069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2021-06-18DOI: 10.1080/14763141.2021.1933580
Paige E Rice, Kiisa Nishikawa, Sophia Nimphius
Limited research exists on the relationship between aesthetic saut de chat performance and muscle-tendon unit (MTU) characteristics of dancers. We developed a weighted parameter ranking (WPR) tool to incorporate aesthetic leaping aspects (i.e., height, peak split angle, average trunk angle and trunk angle range) for correlation with MTU properties. The purpose was to identify the relationship of saut de chat WPR and leap height with maximal plantarflexion strength, medial gastrocnemius (MG) stiffness, Achilles tendon (AT) stiffness and relative peak power (PP). Dancers (n = 18) performed maximal plantarflexion, short-range stretches and isometric ramping contractions on a dynamometer equipped with ultrasound to determine strength, MG stiffness and AT stiffness, respectively. Subjects then performed saut de chat leaps atop force platforms surrounded by motion capture cameras. A principal component analysis (PCA) was performed to compare WPR variable weightings with PCA results and rankings. Moderate-strong relationships were identified among WPR, maximal plantarflexion strength, MG stiffness and PP. Strong-very strong relationships were also identified between leap height and maximal plantarflexion strength, MG stiffness, AT stiffness, peak split angle and PP. A very strong correlation existed between PCA rankings and WPRs. Practitioners may consider developing strength and power capabilities in dancers to improve leaping.
有关舞者的美学跳跃表现与肌肉肌腱单元(MTU)特性之间关系的研究十分有限。我们开发了一种加权参数排序(WPR)工具,将跳跃美学方面(即高度、峰值劈叉角、平均躯干角和躯干角范围)与 MTU 特性相关联。研究的目的是确定 Saut de chat WPR 和跳跃高度与最大跖屈力量、内侧腓肠肌(MG)硬度、跟腱(AT)硬度和相对峰值功率(PP)之间的关系。舞者(n = 18)在配有超声波的测力计上进行最大跖屈、短距离拉伸和等长斜坡收缩,以分别测定力量、腓肠肌僵硬度和跟腱僵硬度。然后,受试者在运动捕捉摄像机环绕的力平台上进行 "saut de chat "跳跃。为了比较 WPR 变量权重与 PCA 结果和排名,我们进行了主成分分析(PCA)。结果表明,WPR、最大跖屈力量、MG 硬度和 PP 之间存在中强关系。在跃起高度与最大跖屈力量、MG 硬度、AT 硬度、峰值分裂角和 PP 之间也发现了很强-非常强的关系。PCA 排名与 WPR 之间存在很强的相关性。练习者可以考虑培养舞蹈演员的力量和发力能力,以提高跳跃能力。
{"title":"Strength and power capabilities predict weighted parameter ranking of <i>saut de chat</i> leaping performance in dancers.","authors":"Paige E Rice, Kiisa Nishikawa, Sophia Nimphius","doi":"10.1080/14763141.2021.1933580","DOIUrl":"10.1080/14763141.2021.1933580","url":null,"abstract":"<p><p>Limited research exists on the relationship between aesthetic <i>saut de chat</i> performance and muscle-tendon unit (MTU) characteristics of dancers. We developed a weighted parameter ranking (WPR) tool to incorporate aesthetic leaping aspects (i.e., height, peak split angle, average trunk angle and trunk angle range) for correlation with MTU properties. The purpose was to identify the relationship of <i>saut de chat</i> WPR and leap height with maximal plantarflexion strength, medial gastrocnemius (MG) stiffness, Achilles tendon (AT) stiffness and relative peak power (PP). Dancers (<i>n</i> = 18) performed maximal plantarflexion, short-range stretches and isometric ramping contractions on a dynamometer equipped with ultrasound to determine strength, MG stiffness and AT stiffness, respectively. Subjects then performed <i>saut de chat</i> leaps atop force platforms surrounded by motion capture cameras. A principal component analysis (PCA) was performed to compare WPR variable weightings with PCA results and rankings. Moderate-strong relationships were identified among WPR, maximal plantarflexion strength, MG stiffness and PP. Strong-very strong relationships were also identified between leap height and maximal plantarflexion strength, MG stiffness, AT stiffness, peak split angle and PP. A very strong correlation existed between PCA rankings and WPRs. Practitioners may consider developing strength and power capabilities in dancers to improve leaping.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39243927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2021-05-25DOI: 10.1080/14763141.2021.1922742
Dominik Hoelbling, Manfred Grafinger, Martin Mattaeus Smiech, Dea Cizmic, Peter Dabnichki, Arnold Baca
The study objective is to test general- and sport-specific adaption during a single training on the Flexibility Trainer. The device is designed to trigger residual muscle tone decreases of the hip-joint muscles by providing (nearly) isokinetic resistance during a full range of motion strength training in adduction/abduction and flexion/extension direction. Static hip flexion and abduction as well as kinematics of double side kicks were analysed on 15 participants before and after training (or rest for controls) to assess general flexibility and sport-specific movement range. Tests were recorded by a Vicon® motion capturing system. Static hip flexion and abduction as well as leg vector spreading angles (VSA) at different nodes of the kick were selected to determine adaptions of active and passive flexibility. Normalised hip joint moments, movement velocities and VSA were calculated to evaluate the training with the device. ANOVAs with 4-repeated measures and Friedman tests were performed to identify time differences and Bonferroni post-hoc test to identify between-subject effects. Significant differences were found for both static flexibility tests (Flexion = 13.65%; Abduction = 9.94%) and the VSA at specific action phases (≤15.15%). Results indicate that short-term adaptions when training with the Flexibility Trainer are exceeding comparable literature showing improved flexibility and sport-specific performance.
{"title":"Acute response on general and sport specific hip joint flexibility to training with novel sport device.","authors":"Dominik Hoelbling, Manfred Grafinger, Martin Mattaeus Smiech, Dea Cizmic, Peter Dabnichki, Arnold Baca","doi":"10.1080/14763141.2021.1922742","DOIUrl":"10.1080/14763141.2021.1922742","url":null,"abstract":"<p><p>The study objective is to test general- and sport-specific adaption during a single training on the <i>Flexibility Trainer</i>. The device is designed to trigger residual muscle tone decreases of the hip-joint muscles by providing (nearly) isokinetic resistance during a full range of motion strength training in adduction/abduction and flexion/extension direction. Static hip flexion and abduction as well as kinematics of double side kicks were analysed on 15 participants before and after training (or rest for controls) to assess general flexibility and sport-specific movement range. Tests were recorded by a Vicon® motion capturing system. Static hip flexion and abduction as well as leg vector spreading angles (VSA) at different nodes of the kick were selected to determine adaptions of active and passive flexibility. Normalised hip joint moments, movement velocities and VSA were calculated to evaluate the training with the device. ANOVAs with 4-repeated measures and Friedman tests were performed to identify time differences and Bonferroni post-hoc test to identify between-subject effects. Significant differences were found for both static flexibility tests (Flexion = 13.65%; Abduction = 9.94%) and the VSA at specific action phases (≤15.15%). Results indicate that short-term adaptions when training with the <i>Flexibility Trainer</i> are exceeding comparable literature showing improved flexibility and sport-specific performance.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39016266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1080/14763141.2024.2369910
Jian-Zhi Lin, Min-Hao Hung, Bo-Jen Ko, Heng-Ju Lee
This study investigates the impact of chronic ankle instability (CAI) on athletes' lower extremity mechanics during bounce drop-jump landings with divided attention. Thirty Division I physical education voluntarily participated in the study. They performed two sets of bounce drop jumps: one set with a divided attention task and the other without. The obtained data were analysed using a paired t-test to compare the outcomes between the divided attention (DA) and non-divided attention (NDA) tasks. Athletes with CAI, during the DA task, displayed higher vertical landing forces, increased ankle inversion velocity, and greater range of motion of the ankle, knee, and hip in the frontal and transverse planes. They also exhibited insufficient neuromuscular preparation of the rectus femoris muscle. Notably, distinct kinematic alterations were observed in the ankle, knee, and hip joints regarding frontal and transverse lower-extremity kinematics. The findings suggest that athletes with CAI experience decreased activation of the rectus femoris muscle, which may impact their dynamic postural stability from pre-landing to ascending phases. Furthermore, the results indicate that individuals with CAI closely replicate the injury mechanisms encountered during a drop-jump landing task with divided attention. These insights offer valuable information about the real-time challenges faced by athletes with CAI.
本研究调查了慢性踝关节不稳定(CAI)对运动员在注意力分散的情况下弹跳落地时下肢力学的影响。30 名一级体育教育自愿参加了这项研究。他们进行了两组弹跳落地:一组有注意力分散任务,另一组没有。所得数据采用配对 t 检验进行分析,以比较注意力分散(DA)和不分散(NDA)任务之间的结果。患有 CAI 的运动员在 DA 任务中表现出更高的垂直着地力、更高的踝关节内翻速度,以及更大的踝关节、膝关节和髋关节在前方和横向平面上的运动范围。他们还表现出股直肌的神经肌肉准备不足。值得注意的是,踝关节、膝关节和髋关节在正面和横向下肢运动学方面出现了明显的运动学改变。研究结果表明,患有 CAI 的运动员股直肌活化程度降低,这可能会影响他们从着地前到上升阶段的动态姿势稳定性。此外,研究结果表明,患有 CAI 的个体在注意力分散的情况下,会密切复制在下落-跳跃着陆任务中遇到的损伤机制。这些见解为 CAI 运动员面临的实时挑战提供了有价值的信息。
{"title":"Analysing lower limb motion and muscle activation in athletes with ankle instability during dual-task drop-jump.","authors":"Jian-Zhi Lin, Min-Hao Hung, Bo-Jen Ko, Heng-Ju Lee","doi":"10.1080/14763141.2024.2369910","DOIUrl":"https://doi.org/10.1080/14763141.2024.2369910","url":null,"abstract":"<p><p>This study investigates the impact of chronic ankle instability (CAI) on athletes' lower extremity mechanics during bounce drop-jump landings with divided attention. Thirty Division I physical education voluntarily participated in the study. They performed two sets of bounce drop jumps: one set with a divided attention task and the other without. The obtained data were analysed using a paired t-test to compare the outcomes between the divided attention (DA) and non-divided attention (NDA) tasks. Athletes with CAI, during the DA task, displayed higher vertical landing forces, increased ankle inversion velocity, and greater range of motion of the ankle, knee, and hip in the frontal and transverse planes. They also exhibited insufficient neuromuscular preparation of the rectus femoris muscle. Notably, distinct kinematic alterations were observed in the ankle, knee, and hip joints regarding frontal and transverse lower-extremity kinematics. The findings suggest that athletes with CAI experience decreased activation of the rectus femoris muscle, which may impact their dynamic postural stability from pre-landing to ascending phases. Furthermore, the results indicate that individuals with CAI closely replicate the injury mechanisms encountered during a drop-jump landing task with divided attention. These insights offer valuable information about the real-time challenges faced by athletes with CAI.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142114068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1080/14763141.2024.2388586
Crystal O Kean, Sophie Burton, Ina Janssen, Victoria Brackley, Alexandra C Atack
This study evaluated the International Society of Biomechanics in Sports (ISBS) women's mentor circle programme. Forty-eight ISBS women members completed a survey that provided insight into how the circles operated, perceived benefits, and challenges to participation. Most circles met every 6-8 weeks with meetings lasting 1 to 1.5 h. However, some circles did not commence or stopped meeting before the end of the 2 years. For those who actively participated, the circles provided personal and professional benefits, which included developing a supportive network and confidence, and improved work-life balance habits. Furthermore, the programme was found to be a valuable use of their time and strengthened their sense of ISBS as a supportive community, increasing their likelihood of staying an ISBS member. Time zone conflicts, lack of a group leader, and changes in individual work or personal life commitments influenced the continuation of some circles over the 2 years. Some respondents did not participate in the circle, and the main reason was lack of knowledge of the programme. Overall, the programme was considered a worthy initiative, providing a supportive network to assist in advancing women biomechanists. Future programmes should ensure a clear alignment between member's expectations and the outcomes of circle participation.
{"title":"Empowering women in sports biomechanics: exploring the impact of mentor circles.","authors":"Crystal O Kean, Sophie Burton, Ina Janssen, Victoria Brackley, Alexandra C Atack","doi":"10.1080/14763141.2024.2388586","DOIUrl":"https://doi.org/10.1080/14763141.2024.2388586","url":null,"abstract":"<p><p>This study evaluated the International Society of Biomechanics in Sports (ISBS) women's mentor circle programme. Forty-eight ISBS women members completed a survey that provided insight into how the circles operated, perceived benefits, and challenges to participation. Most circles met every 6-8 weeks with meetings lasting 1 to 1.5 h. However, some circles did not commence or stopped meeting before the end of the 2 years. For those who actively participated, the circles provided personal and professional benefits, which included developing a supportive network and confidence, and improved work-life balance habits. Furthermore, the programme was found to be a valuable use of their time and strengthened their sense of ISBS as a supportive community, increasing their likelihood of staying an ISBS member. Time zone conflicts, lack of a group leader, and changes in individual work or personal life commitments influenced the continuation of some circles over the 2 years. Some respondents did not participate in the circle, and the main reason was lack of knowledge of the programme. Overall, the programme was considered a worthy initiative, providing a supportive network to assist in advancing women biomechanists. Future programmes should ensure a clear alignment between member's expectations and the outcomes of circle participation.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142114069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1080/14763141.2024.2393188
Hugo Silva, Fábio Yuzo Nakamura, Fabio R Serpiello, João Ribeiro, Paulo Roriz, Rui Marcelino
We adapted the percentage intensity approach to monitor accelerations and decelerations allowing players' individualisation. Forty-two players were monitored during four microcycles via global navigation satellite system devices. Raw velocity and time data were collected to calculate acceleration and deceleration magnitudes according to specific starting speed intervals, and the efforts intensities were established as very low (<25% of the maximal effort), low (25-50%), moderate (50-75%) and high (>75%). Linear regressions and Pearson correlation (r) analysed the relationship between maximal efforts and starting speeds; additionally, mean paired differences compared efforts magnitudes between subsequent starting speed intervals. Most very low intensity accelerations (86%) and decelerations (79%) started from <5 km.h-1. Correlation between maximal efforts and starting speeds were r = -0.97 (p < .001) for acceleration, and r = -0.94 (p < .01) for deceleration. Maximal acceleration decreased as starting speed increases (very large effect sizes), but deceleration is less starting speed dependent (unclear to large effect sizes). This adaptation allows practitioners to individualise accelerations and decelerations classification during real-life scenarios, leading to a more precise training prescription. The very low intensity interval could be excluded to consider only relevant efforts. Maximal acceleration should be collected for each starting speed interval because accelerations are starting speed dependents.
我们对百分比强度方法进行了调整,以监测加速度和减速度,从而实现球员的个性化。我们通过全球导航卫星系统设备对 42 名运动员进行了四个微循环监测。我们收集了原始速度和时间数据,以便根据特定的起始速度区间计算加速和减速幅度,并将努力强度设定为非常低(75%)。线性回归和皮尔逊相关性(r)分析了最大努力和起跑速度之间的关系;此外,平均配对差异比较了随后起跑速度间隔之间的努力幅度。大多数极低强度的加速(86%)和减速(79%)都是从-1 开始的。最大努力与起始速度之间的相关性为:加速 r = -0.97 (p < .001) ,减速 r = -0.94 (p < .01)。最大加速度随着起跑速度的增加而降低(非常大的效应大小),但减速度对起跑速度的依赖性较小(效应大小不明确至大)。这种适应性使练习者能够在真实场景中对加速和减速进行个性化分类,从而制定出更精确的训练处方。可以排除极低强度间歇,只考虑相关的努力。由于加速度与起跑速度有关,因此应收集每个起跑速度区间的最大加速度。
{"title":"Adapting the percentage intensity method to assess accelerations and decelerations in football: moving beyond absolute and arbitrary thresholds.","authors":"Hugo Silva, Fábio Yuzo Nakamura, Fabio R Serpiello, João Ribeiro, Paulo Roriz, Rui Marcelino","doi":"10.1080/14763141.2024.2393188","DOIUrl":"https://doi.org/10.1080/14763141.2024.2393188","url":null,"abstract":"<p><p> We adapted the percentage intensity approach to monitor accelerations and decelerations allowing players' individualisation. Forty-two players were monitored during four microcycles via global navigation satellite system devices. Raw velocity and time data were collected to calculate acceleration and deceleration magnitudes according to specific starting speed intervals, and the efforts intensities were established as very low (<25% of the maximal effort), low (25-50%), moderate (50-75%) and high (>75%). Linear regressions and Pearson correlation (<i>r</i>) analysed the relationship between maximal efforts and starting speeds; additionally, mean paired differences compared efforts magnitudes between subsequent starting speed intervals. Most very low intensity accelerations (86%) and decelerations (79%) started from <5 km.h<sup>-1</sup>. Correlation between maximal efforts and starting speeds were <i>r</i> = -0.97 (<i>p</i> < .001) for acceleration, and <i>r</i> = -0.94 (<i>p</i> < .01) for deceleration. Maximal acceleration decreased as starting speed increases (very large effect sizes), but deceleration is less starting speed dependent (unclear to large effect sizes). This adaptation allows practitioners to individualise accelerations and decelerations classification during real-life scenarios, leading to a more precise training prescription. The very low intensity interval could be excluded to consider only relevant efforts. Maximal acceleration should be collected for each starting speed interval because accelerations are starting speed dependents.</p>","PeriodicalId":49482,"journal":{"name":"Sports Biomechanics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142082349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}