C. Proppe, P. Rivera, E. Hill, T. Housh, Joshua L. Keller, Cory M. Smith, J. V. Anders, Richard Schmidt, G. Johnson, J. Cramer
BACKGROUND: Low-load resistance training with blood flow restriction (LL + BFR) attenuated delayed onset muscle soreness (DOMS) under some conditions. OBJECTIVE: The purpose of this study examined the effects of reciprocal concentric-only elbow flexion-extension muscle actions at 30% of peak torque on indices of DOMS. METHODS: Thirty untrained women (mean ± SD; 22 ± 2.4 years) were randomly assigned to 6 training days of LL + BFR (n= 10), low-load non-BFR (LL) (n= 10), or control (n= 10). Participants completed 4 sets (1 × 30, 3 × 15) of submaximal (30% of peak torque), unilateral, isokinetic (120∘s-1) muscle actions. Indices of DOMS including peak power, resting elbow joint angle (ROM), perceived muscle soreness (VAS), and pain pressure threshold (PPT) were assessed. RESULTS: There were no changes in peak power, ROM, or VAS. There was a significant interaction for PPT. Follow-up analyses indicated PPT increased for the LL + BFR condition (Day 5 > Day 2), but did not decrease below baseline. The results of the present study indicated LL + BFR and LL did not induce DOMS for the elbow extensors in previously untrained women. CONCLUSION: These findings suggested LL + BFR and LL concentric-only resistance training could be an effective training modality to elicit muscular adaptation without inducing DOMS.
{"title":"The effects of blood flow restriction resistance training on indices of delayed onset muscle soreness and peak power","authors":"C. Proppe, P. Rivera, E. Hill, T. Housh, Joshua L. Keller, Cory M. Smith, J. V. Anders, Richard Schmidt, G. Johnson, J. Cramer","doi":"10.3233/ies-210158","DOIUrl":"https://doi.org/10.3233/ies-210158","url":null,"abstract":"BACKGROUND: Low-load resistance training with blood flow restriction (LL + BFR) attenuated delayed onset muscle soreness (DOMS) under some conditions. OBJECTIVE: The purpose of this study examined the effects of reciprocal concentric-only elbow flexion-extension muscle actions at 30% of peak torque on indices of DOMS. METHODS: Thirty untrained women (mean ± SD; 22 ± 2.4 years) were randomly assigned to 6 training days of LL + BFR (n= 10), low-load non-BFR (LL) (n= 10), or control (n= 10). Participants completed 4 sets (1 × 30, 3 × 15) of submaximal (30% of peak torque), unilateral, isokinetic (120∘s-1) muscle actions. Indices of DOMS including peak power, resting elbow joint angle (ROM), perceived muscle soreness (VAS), and pain pressure threshold (PPT) were assessed. RESULTS: There were no changes in peak power, ROM, or VAS. There was a significant interaction for PPT. Follow-up analyses indicated PPT increased for the LL + BFR condition (Day 5 > Day 2), but did not decrease below baseline. The results of the present study indicated LL + BFR and LL did not induce DOMS for the elbow extensors in previously untrained women. CONCLUSION: These findings suggested LL + BFR and LL concentric-only resistance training could be an effective training modality to elicit muscular adaptation without inducing DOMS.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48391366","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}
D. Jaimes, J. Petro, D. Bonilla, Johanny G. Cárdenas, A. O. Duarte, Dennis Contreras
BACKGROUND: Supervised strength training has been shown to promote physiological adaptations in children and youth that can be beneficial to the process of physical growth and developed, and general health status. METHODS: Sixty-three children (9.2 ± 0.5 years old) were randomly assigned to training groups: multi jumps (MJ) (n= 20), sled towing (ST) (n= 21), or uphill running (UR) (n= 22). The following tests were applied before and after each intervention: vertical jump (ABK, CMJ, SJ), standing broad jump (SBJ), velocity/agility 4 × 10 m, and 20 m sprint test (ST20m). RESULTS: After 8 weeks of training, statistically significant changes were found in all study variables for all groups, but with different effect sizes. In the ABK jump, the largest effect size was observed in UR (1.40, 0.97–1.85), while in ST and MJ it was medium (0.67, 0.44–0.98 and 0.48, 0.17–0.82, respectively). Similarly, the effect size in the SJ jump was large for the UR and ST groups (1.10, 0.78–1.51 and 1.30, 0.98–1.64, respectively) and medium in MJ (0.56, 0.24–0.97). However, the magnitude of the effect registered in SBJ was large in MJ (0.80, 0.55–1.15) and medium in UR and ST (0.56, 0.32–0.86 and 0.64, 0.42–1.013, respectively). CONCLUSIONS: All three training programs improve jumping and velocity/agility performance but based on clinical significance, UR and ST methods can be considered more efficient to improve physical performance in children.
{"title":"Effects of three 8-week strength training programs on jump, speed and agility performance in prepubertal children","authors":"D. Jaimes, J. Petro, D. Bonilla, Johanny G. Cárdenas, A. O. Duarte, Dennis Contreras","doi":"10.3233/ies-210117","DOIUrl":"https://doi.org/10.3233/ies-210117","url":null,"abstract":"BACKGROUND: Supervised strength training has been shown to promote physiological adaptations in children and youth that can be beneficial to the process of physical growth and developed, and general health status. METHODS: Sixty-three children (9.2 ± 0.5 years old) were randomly assigned to training groups: multi jumps (MJ) (n= 20), sled towing (ST) (n= 21), or uphill running (UR) (n= 22). The following tests were applied before and after each intervention: vertical jump (ABK, CMJ, SJ), standing broad jump (SBJ), velocity/agility 4 × 10 m, and 20 m sprint test (ST20m). RESULTS: After 8 weeks of training, statistically significant changes were found in all study variables for all groups, but with different effect sizes. In the ABK jump, the largest effect size was observed in UR (1.40, 0.97–1.85), while in ST and MJ it was medium (0.67, 0.44–0.98 and 0.48, 0.17–0.82, respectively). Similarly, the effect size in the SJ jump was large for the UR and ST groups (1.10, 0.78–1.51 and 1.30, 0.98–1.64, respectively) and medium in MJ (0.56, 0.24–0.97). However, the magnitude of the effect registered in SBJ was large in MJ (0.80, 0.55–1.15) and medium in UR and ST (0.56, 0.32–0.86 and 0.64, 0.42–1.013, respectively). CONCLUSIONS: All three training programs improve jumping and velocity/agility performance but based on clinical significance, UR and ST methods can be considered more efficient to improve physical performance in children.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48259557","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}
Jun-hee Kim, O. Kwon, U. Hwang, Sung-hoon Jung, Sun-hee Ahn, Gyeong-tae Gwak
BACKGROUND: The focus of exercises for restoring the imbalance between scapular upward rotator muscles – upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) – commonly aims to increase SA and LT activities while not increasing UT activity. OBJECTIVES: The purpose of this study was to compare the activity of the UT, SA, and LT muscles during scapation and protraction exercises, which are two traditional exercises, and during a newly designed scapular upward rotation (SUR) exercise. METHODS: A total of 29 healthy young adult men performed all three exercises with maximum isometric contraction. The electromyographic activities of the UT, SA, and LT were recorded. RESULTS: UT demonstrated the highest activity during scapation. SA activity was the lowest during protraction. However, no difference was found in SA activity during the performance of scapation and SUR. The SA/UT ratio was the highest during scapation. CONCLUSIONS: SUR is a new exercise that can be performed at moderate intensity for shoulder rehabilitation to restore scapular upward rotator muscle imbalance.
{"title":"Comparison of scapular upward rotator muscle activities and activity ratios during three scapular upward rotator strengthening exercises","authors":"Jun-hee Kim, O. Kwon, U. Hwang, Sung-hoon Jung, Sun-hee Ahn, Gyeong-tae Gwak","doi":"10.3233/ies-210181","DOIUrl":"https://doi.org/10.3233/ies-210181","url":null,"abstract":"BACKGROUND: The focus of exercises for restoring the imbalance between scapular upward rotator muscles – upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) – commonly aims to increase SA and LT activities while not increasing UT activity. OBJECTIVES: The purpose of this study was to compare the activity of the UT, SA, and LT muscles during scapation and protraction exercises, which are two traditional exercises, and during a newly designed scapular upward rotation (SUR) exercise. METHODS: A total of 29 healthy young adult men performed all three exercises with maximum isometric contraction. The electromyographic activities of the UT, SA, and LT were recorded. RESULTS: UT demonstrated the highest activity during scapation. SA activity was the lowest during protraction. However, no difference was found in SA activity during the performance of scapation and SUR. The SA/UT ratio was the highest during scapation. CONCLUSIONS: SUR is a new exercise that can be performed at moderate intensity for shoulder rehabilitation to restore scapular upward rotator muscle imbalance.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46123171","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}
Kazuaki Kinoshita, Y. Hoshino, Naoko Yokota, Masashi Hashimoto, Y. Nishizawa, N. Kida
BACKGROUND: Handstand is the most important fundamental skill in gymnastics. A gradual and well-balanced increase in muscle loading in a manner is preferred for young beginners and/or recovering gymnasts to safely achieve the muscle strength required to perform a stable handstand. OBJECTIVE: To examine upper limb muscle activity during different levels of handstand training positions. METHODS: This study utilized four different positions for progressive handstand training; namely, the 90, 135, elbow stand, and handstand positions. The activities of eight upper limb muscles (upper, middle, and lower trapezius; serratus anterior; anterior and middle deltoid; infraspinatus; and latissimus dorsi were measured by surface electromyography (EMG) for each position. The percentages of EMG in each muscle compared to the values during maximum voluntary contraction were calculated and compared between the positions. RESULTS: Muscle activity around the shoulder increased gradually throughout the progression of the four handstand training positions. Furthermore, the muscles required for scapular stabilization, such as the upper and middle trapezius and serratus anterior muscles, were activated at levels similar to those for a handstand without performing this movement. CONCLUSIONS: A progressive handstand training program of four different positions resulted in gradual and well-balanced increases in muscle activity.
{"title":"Stepwise increase of upper limb muscle activity induced by progressive 4 positions of a handstand training","authors":"Kazuaki Kinoshita, Y. Hoshino, Naoko Yokota, Masashi Hashimoto, Y. Nishizawa, N. Kida","doi":"10.3233/ies-210169","DOIUrl":"https://doi.org/10.3233/ies-210169","url":null,"abstract":"BACKGROUND: Handstand is the most important fundamental skill in gymnastics. A gradual and well-balanced increase in muscle loading in a manner is preferred for young beginners and/or recovering gymnasts to safely achieve the muscle strength required to perform a stable handstand. OBJECTIVE: To examine upper limb muscle activity during different levels of handstand training positions. METHODS: This study utilized four different positions for progressive handstand training; namely, the 90, 135, elbow stand, and handstand positions. The activities of eight upper limb muscles (upper, middle, and lower trapezius; serratus anterior; anterior and middle deltoid; infraspinatus; and latissimus dorsi were measured by surface electromyography (EMG) for each position. The percentages of EMG in each muscle compared to the values during maximum voluntary contraction were calculated and compared between the positions. RESULTS: Muscle activity around the shoulder increased gradually throughout the progression of the four handstand training positions. Furthermore, the muscles required for scapular stabilization, such as the upper and middle trapezius and serratus anterior muscles, were activated at levels similar to those for a handstand without performing this movement. CONCLUSIONS: A progressive handstand training program of four different positions resulted in gradual and well-balanced increases in muscle activity.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43406542","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}
Jakub Jačiško, Martin Stribrny, J. Novák, Andrew M. Busch, P. Černý, P. Kolář, A. Kobesova
BACKGROUND: The evaluation of postural trunk muscle function is a critical component of clinical assessment in patients with musculoskeletal pain and dysfunction. Postural activation of the trunk muscles has been evaluated by various methods. This study evaluates the correlation between subjective assessment of postural trunk muscle function with an objective measurement of abdominal wall expansion. METHODS: Twenty-five healthy participants (16 women, 9 men, age 22.4 years) were assessed. The subjective assessment was performed by two experienced Dynamic Neuromuscular Stabilization (DNS) clinicians evaluating the quality of trunk stabilization using five postural stability tests through palpation and observation. Interrater reliability was determined using an intraclass correlation coefficients (ICC). Objective measurement was performed using a new device (DNS Brace) which externally measures abdominal wall pressure. Spearman rank correlations were calculated for both palpation and observation measures with DNS Brace data. RESULTS: The interrater reliability (ICC2,k) estimates demonstrated moderate reliability in palpation measures for three DNS tests: Hip flexion test, Diaphragm test, & Intra-abdominal pressure regulation test (IAPRT) (ICC = 0.645–0.707). For observation measures, good reliability was found in IAPRT (ICC = 0.835), and three tests demonstrated moderate reliability: Hip flexion test, Diaphragm test, & Breathing Stereotype (ICC = 0.577–0.695). Correlation analysis demonstrated several moderate to strong correlations between palpation and DNS brace values (Assessor 1): IAPRT, rs= 0.580, p= 0.002, Diaphragm test, rs= 0.543, p= 0.005, (Assessor 2): IAPRT, rs= 0.776, p< 0.001, Breathing Stereotype, rs= 0.625, p= 0.001, Diaphragm test, rs= 0.519, p= 0.008, Hip Flexion test, rs= 0.536, p= 0.006, and Arm Elevation test, rs= 0.460, p= 0.021. For observation, several moderate correlations were demonstrated with DNS brace values (Assessor 1): Arm Elevation test, rs= 0.472, p= 0.017, (Assessor 2) Diaphragm test, rs= 0.540, p= 0.005, IAPRT rs= 0.475, p= 0.016, Hip Flexion test, rs= 0.485, p= 0.014, and Arm Elevation, rs= 0.451, p= 0.024. CONCLUSION: Based on inter-rater reliability and DNS brace correlations with trained DNS professionals, the IAPRT, Diaphragm test, and Hip Flexion test may prove useful when assessing asymptomatic individuals. More research is needed in order to establish the utility of DNS brace and clinical testing both in asymptomatic and back pain populations. DNS tests must be supplemented by further examinations for definitive clinical decision making.
{"title":"Correlation between palpatory assessment and pressure sensors in response to postural trunk tests","authors":"Jakub Jačiško, Martin Stribrny, J. Novák, Andrew M. Busch, P. Černý, P. Kolář, A. Kobesova","doi":"10.3233/ies-205238","DOIUrl":"https://doi.org/10.3233/ies-205238","url":null,"abstract":"BACKGROUND: The evaluation of postural trunk muscle function is a critical component of clinical assessment in patients with musculoskeletal pain and dysfunction. Postural activation of the trunk muscles has been evaluated by various methods. This study evaluates the correlation between subjective assessment of postural trunk muscle function with an objective measurement of abdominal wall expansion. METHODS: Twenty-five healthy participants (16 women, 9 men, age 22.4 years) were assessed. The subjective assessment was performed by two experienced Dynamic Neuromuscular Stabilization (DNS) clinicians evaluating the quality of trunk stabilization using five postural stability tests through palpation and observation. Interrater reliability was determined using an intraclass correlation coefficients (ICC). Objective measurement was performed using a new device (DNS Brace) which externally measures abdominal wall pressure. Spearman rank correlations were calculated for both palpation and observation measures with DNS Brace data. RESULTS: The interrater reliability (ICC2,k) estimates demonstrated moderate reliability in palpation measures for three DNS tests: Hip flexion test, Diaphragm test, & Intra-abdominal pressure regulation test (IAPRT) (ICC = 0.645–0.707). For observation measures, good reliability was found in IAPRT (ICC = 0.835), and three tests demonstrated moderate reliability: Hip flexion test, Diaphragm test, & Breathing Stereotype (ICC = 0.577–0.695). Correlation analysis demonstrated several moderate to strong correlations between palpation and DNS brace values (Assessor 1): IAPRT, rs= 0.580, p= 0.002, Diaphragm test, rs= 0.543, p= 0.005, (Assessor 2): IAPRT, rs= 0.776, p< 0.001, Breathing Stereotype, rs= 0.625, p= 0.001, Diaphragm test, rs= 0.519, p= 0.008, Hip Flexion test, rs= 0.536, p= 0.006, and Arm Elevation test, rs= 0.460, p= 0.021. For observation, several moderate correlations were demonstrated with DNS brace values (Assessor 1): Arm Elevation test, rs= 0.472, p= 0.017, (Assessor 2) Diaphragm test, rs= 0.540, p= 0.005, IAPRT rs= 0.475, p= 0.016, Hip Flexion test, rs= 0.485, p= 0.014, and Arm Elevation, rs= 0.451, p= 0.024. CONCLUSION: Based on inter-rater reliability and DNS brace correlations with trained DNS professionals, the IAPRT, Diaphragm test, and Hip Flexion test may prove useful when assessing asymptomatic individuals. More research is needed in order to establish the utility of DNS brace and clinical testing both in asymptomatic and back pain populations. DNS tests must be supplemented by further examinations for definitive clinical decision making.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/ies-205238","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45124804","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}
L. Catino, C. Malloggi, Stefano Scarano, Valeria Cerina, V. Rota, L. Tesio
BACKGROUND: A method of measurement of voluntary activation (VA, percent of full muscle recruitment) during isometric and isokinetic concentric contractions of the quadriceps femoris (QF) at 60∘/s and 120∘/s was previously validated. OBJECTIVE: This study aimed to quantify the test-retest minimal real difference (MRD) of VA during isometric (ISOM) and isokinetic concentric contractions of QF (100∘/s, ISOK) in a sample of healthy individuals. METHODS: VA was measured through the interpolated twitch technique. Pairs of electrical stimuli were delivered to the QF at 40∘ of knee flexion during maximal voluntary contractions. Twenty-five healthy participants (20–38 years, 12 women, 13 men) completed two testing sessions with a 14-day interval. VA values were linearized through logit transformation (VAl). The MRD was estimated from intraclass correlation coefficients (model 2.1). RESULTS: The VA (median, range) was 84.20% (38.2–99.9%) in ISOM and 94.22% (33.8–100%) in ISOK. MRD was 0.78 and 1.12 logit for ISOM and ISOK, respectively. As an example, in terms of percent VA these values correspond to a change from 76% to 95% and from 79% to 98% in ISOM and in ISOK, respectively. CONCLUSIONS: The provided MRD values allow to detect significant individual changes in VA, as expected after training and rehabilitation programs.
{"title":"Quadriceps activation during maximal isometric and isokinetic contractions: The minimal real difference and its implications","authors":"L. Catino, C. Malloggi, Stefano Scarano, Valeria Cerina, V. Rota, L. Tesio","doi":"10.3233/ies-203241","DOIUrl":"https://doi.org/10.3233/ies-203241","url":null,"abstract":"BACKGROUND: A method of measurement of voluntary activation (VA, percent of full muscle recruitment) during isometric and isokinetic concentric contractions of the quadriceps femoris (QF) at 60∘/s and 120∘/s was previously validated. OBJECTIVE: This study aimed to quantify the test-retest minimal real difference (MRD) of VA during isometric (ISOM) and isokinetic concentric contractions of QF (100∘/s, ISOK) in a sample of healthy individuals. METHODS: VA was measured through the interpolated twitch technique. Pairs of electrical stimuli were delivered to the QF at 40∘ of knee flexion during maximal voluntary contractions. Twenty-five healthy participants (20–38 years, 12 women, 13 men) completed two testing sessions with a 14-day interval. VA values were linearized through logit transformation (VAl). The MRD was estimated from intraclass correlation coefficients (model 2.1). RESULTS: The VA (median, range) was 84.20% (38.2–99.9%) in ISOM and 94.22% (33.8–100%) in ISOK. MRD was 0.78 and 1.12 logit for ISOM and ISOK, respectively. As an example, in terms of percent VA these values correspond to a change from 76% to 95% and from 79% to 98% in ISOM and in ISOK, respectively. CONCLUSIONS: The provided MRD values allow to detect significant individual changes in VA, as expected after training and rehabilitation programs.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/ies-203241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49479309","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: It remains unclear if plyometric training as a single component could improve landing mechanics that are potentially associated with lower risk of ACL injury in the long term OBJECTIVE: The purpose of this study was to investigate the influence of experience undertaking plyometrics on landing biomechanics in female athletes. METHODS: Non-jumpers with little experience in plyometric training (12 female college swimmers) and jumpers with five years of experience in plyometric training (12 female college long jumpers and high jumpers) were recruited to participate in two testing sessions: an isokinetic muscle force test for the dominant leg at 120∘/s and a 40-cm drop landing test. An independent t test was applied to detect any significant effects between cohorts for selected muscle force, kinematic, kinetic, and electromyography variables. RESULTS: While female jumpers exhibited greater quadriceps eccentric strength (P= 0.013) and hamstring concentric strength (P= 0.023) during isokinetic testing than female swimmers, no significant differences were observed in kinematics, kinetics, and muscle activities during both drop landing and drop jumping. CONCLUSIONS: The results suggest that the female jumpers did not present any training-induced modification in landing mechanics regarding reducing injury risks compared with the swimmers. The current study revealed that plyometric training as a single component may not guarantee the development of low-risk landing mechanics for young female athletes.
{"title":"Differences in strength and landing biomechanics between female jumpers and swimmers","authors":"M. Ruan, Qiang Zhang, Xin Zhang, Jing Hu, Xie Wu","doi":"10.3233/ies-210149","DOIUrl":"https://doi.org/10.3233/ies-210149","url":null,"abstract":"BACKGROUND: It remains unclear if plyometric training as a single component could improve landing mechanics that are potentially associated with lower risk of ACL injury in the long term OBJECTIVE: The purpose of this study was to investigate the influence of experience undertaking plyometrics on landing biomechanics in female athletes. METHODS: Non-jumpers with little experience in plyometric training (12 female college swimmers) and jumpers with five years of experience in plyometric training (12 female college long jumpers and high jumpers) were recruited to participate in two testing sessions: an isokinetic muscle force test for the dominant leg at 120∘/s and a 40-cm drop landing test. An independent t test was applied to detect any significant effects between cohorts for selected muscle force, kinematic, kinetic, and electromyography variables. RESULTS: While female jumpers exhibited greater quadriceps eccentric strength (P= 0.013) and hamstring concentric strength (P= 0.023) during isokinetic testing than female swimmers, no significant differences were observed in kinematics, kinetics, and muscle activities during both drop landing and drop jumping. CONCLUSIONS: The results suggest that the female jumpers did not present any training-induced modification in landing mechanics regarding reducing injury risks compared with the swimmers. The current study revealed that plyometric training as a single component may not guarantee the development of low-risk landing mechanics for young female athletes.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/ies-210149","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47724080","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}
BACKROUND AND OBJECTIVE: Grip and knee strength are commonly measured but controversy exists as to whether either is a proxy for the other. The purpose of this meta-analysis was to summarize the correlation between the 2 variables. METHODS: Relevant literature was sought using PubMed, Google, and a hand search. Information on populations, measurements, and correlations were extracted. Correlational data were subjected to meta-analysis. RESULTS: Results from 17 studies were consolidated. The summary correlation between grip and knee extension strength was 0.64 with 95% CI of 0.57 to 0.71. Data were highly heterogeneous but did not show publication bias. CONCLUSION: The correlation between the grip and knee extension strength is good. However, it is not good enough to justify using either as a proxy for the other.
{"title":"Correlation of grip and knee extension strength in mature adults","authors":"R. W. Bohannon","doi":"10.3233/IES-210161","DOIUrl":"https://doi.org/10.3233/IES-210161","url":null,"abstract":"BACKROUND AND OBJECTIVE: Grip and knee strength are commonly measured but controversy exists as to whether either is a proxy for the other. The purpose of this meta-analysis was to summarize the correlation between the 2 variables. METHODS: Relevant literature was sought using PubMed, Google, and a hand search. Information on populations, measurements, and correlations were extracted. Correlational data were subjected to meta-analysis. RESULTS: Results from 17 studies were consolidated. The summary correlation between grip and knee extension strength was 0.64 with 95% CI of 0.57 to 0.71. Data were highly heterogeneous but did not show publication bias. CONCLUSION: The correlation between the grip and knee extension strength is good. However, it is not good enough to justify using either as a proxy for the other.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/IES-210161","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44127165","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: Lower-extremity muscle strength and ankle flexibility play key roles in underwater swimming movements. OBJECTIVES: To investigate the relationship between knee isokinetic strength and the speed of underwater dolphin kicks (UDK-S) in competitive male swimmers and identify whether ankle flexibility affects the association between knee isokinetic strength and UDK-S. METHODS: Fifty-two highly trained male swimmers participated in this study. The speed at which the participants travelled 15 m performing UDKs was calculated as UDK-S. Knee flexor and extensor concentric isokinetic strength at fast (240∘/s) and slow (60∘/s) velocities and ankle flexibility were evaluated. Bayesian framework analysis was conducted to examine the relationship between these variables and determine whether this relationship is influenced by ankle flexibility. RESULTS: There was strong-to-extremely strong evidence (Bayes factor = 24.4 to 198.3) that knee extensor (60∘/s) and knee flexor (60∘/s and 240∘/s) strength are positively and generally moderately correlated with UDK-S. Ankle plantar flexion flexibility was identified to be a moderator between knee extensor strength (60∘/s) and UDK-S. CONCLUSIONS: Knee extensor and knee flexor strength were significantly correlated with UDK-S, and the relationship between knee muscle strength and UDK-S was influenced by ankle plantar flexion flexibility in male competitive swimmers.
{"title":"The effect of ankle flexibility on the relationship between knee isokinetic strength and the speed of underwater dolphin kicks in male competitive swimmers","authors":"Yupeng Shen, Yanqing Fu, Yu Ge, Yuhong Wen","doi":"10.3233/IES-200255","DOIUrl":"https://doi.org/10.3233/IES-200255","url":null,"abstract":"BACKGROUND: Lower-extremity muscle strength and ankle flexibility play key roles in underwater swimming movements. OBJECTIVES: To investigate the relationship between knee isokinetic strength and the speed of underwater dolphin kicks (UDK-S) in competitive male swimmers and identify whether ankle flexibility affects the association between knee isokinetic strength and UDK-S. METHODS: Fifty-two highly trained male swimmers participated in this study. The speed at which the participants travelled 15 m performing UDKs was calculated as UDK-S. Knee flexor and extensor concentric isokinetic strength at fast (240∘/s) and slow (60∘/s) velocities and ankle flexibility were evaluated. Bayesian framework analysis was conducted to examine the relationship between these variables and determine whether this relationship is influenced by ankle flexibility. RESULTS: There was strong-to-extremely strong evidence (Bayes factor = 24.4 to 198.3) that knee extensor (60∘/s) and knee flexor (60∘/s and 240∘/s) strength are positively and generally moderately correlated with UDK-S. Ankle plantar flexion flexibility was identified to be a moderator between knee extensor strength (60∘/s) and UDK-S. CONCLUSIONS: Knee extensor and knee flexor strength were significantly correlated with UDK-S, and the relationship between knee muscle strength and UDK-S was influenced by ankle plantar flexion flexibility in male competitive swimmers.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/IES-200255","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47683801","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: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.
{"title":"Hip and ankle strength and range of motion in female soccer players with dynamic knee valgus","authors":"Y. Jo, Young Kyun Kim","doi":"10.3233/IES-200260","DOIUrl":"https://doi.org/10.3233/IES-200260","url":null,"abstract":"BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.","PeriodicalId":54915,"journal":{"name":"Isokinetics and Exercise Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/IES-200260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42816566","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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