An Analysis of Causal Relationship between Isokinetic Muscle Function and One-Leg Maximum Vertical Jump of Elementary Students

AbstractThe aim of this study was to evaluate the symmetry of anthropometry and muscle function in cross-country skiers and their association to vertical jumping power. Twenty cross-country skiers were recruited (21.7 ± 3.8 yrs, 180.6 ± 7.6 cm, 73.2 ± 7.6 kg). Anthropometric data was obtained using an iDXA scan. VO2maxwas determined using the diagonal stride technique on a ski treadmill. Bilateral functional tests for the upper and lower body were the handgrip and standing heel-rise tests. Vertical jump height and power were assessed with a counter movement jump. Percent asymmetry was calculated using a symmetry index and four absolute symmetry index levels. At a group level the upper body was more asymmetrical with regard to lean muscle mass (p = 0.022, d = 0.17) and functional strength (p = 0.019, d = 0.51) than the lower body. At an individual level the expected frequencies for absolute symmetry level indexes showed the largest deviation from zero for the heel-rise test (χ2 = 16.97, p = 0.001), while the leg lean mass deviated the least (χ2 = 0.42, p = 0.517). No relationships were observed between absolute symmetry level indexes of the lower body and counter movement jump performance (p > 0.05). As a group the skiers display a more asymmetrical upper body than lower body regarding muscle mass and strength. Interestingly at the individual level, despite symmetrical lean leg muscle mass the heel-rise test showed the largest asymmetry. This finding indicates a mismatch in muscle function for the lower body.

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Peak vertical jump power predicts radial bone strength better than hand grip strength in healthy individuals.

Communications in Kinesiology ◽

10.51224/cik.v1i2.13 ◽

2021 ◽

Vol 1 (2) ◽

Author(s):

Vanessa Yingling ◽

Rebekkah Reichert ◽

Andrew Denys ◽

Priscilla Franson ◽

Kimberly Espartero ◽

...

Keyword(s):

Cortical Bone ◽

Grip Strength ◽

Bone Strength ◽

Bone Mineral ◽

Muscle Function ◽

Vertical Jump ◽

Mineral Density ◽

Strength Parameters ◽

Jump Power ◽

The Relationship

Osteoporosis is considered a pediatric disease with geriatric consequences. However, measuring bone strength in children is complex and creates a practical problem for health professionals, teachers and parents. A non-invasive measure of muscle fitness that correlates to bone strength may provide a means to monitor bone strength throughout the lifespan. Therefore, the purpose of this study was to investigate the relationship between common muscle function tests (relative grip strength (RGS), peak vertical jump power (PP)) and bone strength in the radial diaphysis and epiphysis of a healthy population. Healthy participants (n=147 (81 female)) performed a bilateral grip strength test using a hand dynamometer, and a maximal vertical jump test. Peak vertical jump power was calculated from maximal jump height using the Sayer’s equation. Moment of inertia (MoI), cortical area (CoA), cortical bone mineral density (cBMD), and polar strength-strain index (SSIp) were measured using peripheral Quantitative Computed Tomography (pQCT) to determine bone strength parameters at the 66% radial site (predominantly cortical bone). At the 4% site (trabecular bone site), bone mineral content (vBMC.tb), bone mineral density (vBMD.tb), total area (ToA.tb) and bone strength index (BSIc) were measured. Hierarchical multiple regression analyses determined the relationship of each muscle function test for each bone envelope (cortical and trabecular). For the cortical bone measurements: RGS, and PP were both significantly correlated with CoA, MoI, and SSIp. Peak vertical jump power predicted bone strength parameters to a greater extent compared to RGS. For the trabecular bone envelope, RGS was not a predictor of bone strength however peak power was a significant predictor of bone strength parameters. Peak vertical jump power was a significant predictor of bone strength at both trabecular and cortical radial sites. Interestingly PP, a lower limb measurement explained the most variance in the bone strength of the upper limb.

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B30 Lower limbs muscular power in vertical jump estimated by human musculo-skeletal model considering bi-articular muscle function

The Proceedings of Joint Symposium Symposium on Sports Engineering Symposium on Human Dynamics ◽

10.1299/jsmesports.2008.0_335 ◽

2008 ◽

Vol 2008 (0) ◽

pp. 335-340

Author(s):

Isamu NISHIDA ◽

Tatsuhiko SAKAGUCHI ◽

Masato MAEDA ◽

Keiichi SHIRASE

Keyword(s):

Muscle Function ◽

Vertical Jump ◽

Lower Limbs ◽

Muscular Power ◽

Skeletal Model

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Effects of isokinetic eccentric versus traditional lower body resistance training on muscle function: examining a multiple-joint short-term training model

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2018-0333 ◽

2019 ◽

Vol 44 (2) ◽

pp. 118-126 ◽

Cited By ~ 1

Author(s):

Joshua P. Gordon ◽

Brennan J. Thompson ◽

Joshua S. Crane ◽

Eadric Bressel ◽

Dale R. Wagner

Keyword(s):

Resistance Training ◽

Muscle Function ◽

Vertical Jump ◽

Late Phase ◽

Peak Torque ◽

Knee Extensors ◽

Lower Body ◽

Eccentric Training ◽

Resistance Training Program ◽

Leg Press

Early adaptations in eccentric training show several advantages over those in concentric training. The purpose of this study was to quantify the effects of 4 weeks of multiple-joint eccentric versus traditional leg press (TLP) training on muscle strength, rate of torque development (RTD), and jump and sprint performance adaptations. Twenty-six resistance-trained adults performed either an eccentric or a TLP resistance-training program twice per week for 4 weeks. Single-joint isometric maximal and rapid strength (peak torque and RTD, respectively) and isokinetic strength of the knee extensors and flexors, multiple-joint eccentric strength, leg press strength (1-repetition maximum), 40-m sprint, and vertical and long jump were measured before, at the midpoint, and after a 4-week training period. Four weeks of isokinetic multiple-joint eccentric training elicited greater test-specific strength gains (effect size (ES) = 1.06) compared with TLP training (ES = 0.11). The eccentric group also yielded moderate improvements in the middle-late phase RTD (RTD100–200; ES = 0.51 and 0.54 for the knee flexors and extensors, respectively), whereas the TLP group showed small-moderate improvements (ES = 0.37). The majority of the single-joint strength variables showed negligible improvements. Performance tests showed no (broad jump) to small (vertical jump; sprint for the leg press) improvements. Multiple-joint eccentric training induced significant improvements in lower body strength in a short amount of time in a recreationally trained population. These accelerated adaptations along with the lower energy requirements of eccentric exercise, may be useful for clinicians or practitioners when prescribing training programs for those who are injured, sedentary, or elderly as a means to elicit time- and metabolically efficient muscle function improvements.

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Peak vertical jump power predicts radial bone strength better than hand grip strength in healthy individuals

10.31236/osf.io/2t39k ◽

2019 ◽

Author(s):

Vanessa Rose Yingling ◽

Rebekkah Reichert ◽

Andrew Denys ◽

Priscilla Franson ◽

Kimberly Espartero ◽

...

Keyword(s):

Trabecular Bone ◽

Cortical Bone ◽

Grip Strength ◽

Bone Strength ◽

Muscle Function ◽

Peak Power ◽

Vertical Jump ◽

Strength Parameters ◽

Jump Power ◽

The Relationship

Optimizing bone strength is key to long term bone health and potentially avoidance of Osteoporotic fracture later in life. Osteoporosis is considered a pediatric disease with geriatric consequences. However, measuring bone strength in children is complex and creates a practical problem for health professionals, teachers and parents. Muscle cross sectional area (MCSA) correlates with bone strength but muscular fitness measures may serve as a better proxy to assess bone strength. A non-invasive measure of muscle fitness that correlates to bone strength may provide a means to monitor bone strength throughout the lifespan. PURPOSE: To investigate the relationship between common muscle function tests (relative grip strength (RGS), peak vertical jump power (PP)) and bone strength in the radial diaphysis and epiphysis of a healthy population. METHODS: Healthy participants (n=147 (81 female)) performed a bilateral grip strength test using a hand dynamometer, and a maximal vertical jump test. Peak vertical jump power was calculated from maximal jump height using the Sayer’s equation. Moment of inertia (MoI), cortical area (CoA), cortical bone mineral density (cBMD), and polar strength-strain index (SSIp) were measured using peripheral Quantitative Computed Tomography (pQCT) to determine bone strength parameters at the 66% radial site (predominantly cortical bone). At the 4% site (trabecular bone site), vBMC.tb, vBMD.tb, ToA.tb and BSIc were measured. Hierarchical multiple regression analyses determined the relationship of each muscle function test for each bone envelope (cortical and trabecular). RESULTS: For the cortical bone measurements: RGS, and PP were both significantly correlated with CoA, MoI, and SSIp. However, neither of the muscle function measures were correlated with cBMD. Peak vertical jump power predicted bone strength parameters to a greater extent compared to RGS. Peak Power had the largest R2 values of all 3 measurements SSIp (R2=0.541, p<0.0001), CoA (R2=0.597, p<0.0001) and MoI (R2=0.568, p<0.0001). For the trabecular bone envelope, RGS was not a predictor of bone strength however peak power was a significant predictor of vBMC.tb (R2=0.548, p<0.0001), vBMD.tb (R2=0.267, p<0.0001) ToA..tb (R2=0.419, p<0.0001) and BSIc (R2=0.489, p<0.0001). CONCLUSION: Muscle function tests provide insight into bone strength in healthy adult populations. Both RGS and PP correlated with bone strength in the cortical envelope but RGS was not a predictor of trabecular bone strength parameters at the 4% radial site. Peak vertical jump power was a significant predictor of bone strength at both trabecular and cortical radial sites. Interestingly PP, a lower limb measurement explained the most variance in the bone strength of the upper limb. Lower limb muscle power calculated by vertical jump assessment could provide a means to monitor and assess bone health.

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Bacteriophages Associated with Turkey Coecums in Bluecomb-Infected and Healthy Birds

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063044 ◽

1969 ◽

Vol 27 ◽

pp. 226-227

Author(s):

A. E. Ritchie

Keyword(s):

Host Cell ◽

Causal Relationship ◽

Cell Cultures ◽

Cell Interaction ◽

Etiologic Agent ◽

Viral Origin ◽

Intestinal Contents ◽

Host Cell Interaction

The cause of bluecomb disease in turkeys is unknown. Filtration of infective intestinal contents suggests a viral origin. To date, it has not been possible to isolate the etiologic agent in various cell cultures. The purpose of this work was to characterize as many virus-like entities as were recognizable in intestines of both healthy and bluecomb-infected turkeys. By a comparison of the viral populations it was hoped that some insight might be gained into the cause of this disease. Studies of turkey hemorraghic enteritis by Gross and Moore (Avian Dis. 11: 296-307, 1967) have suggested that a bacteriophage-host cell interaction may bear some causal relationship to that disease.

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