scholarly journals 25(OH)D3 Levels Relative to Muscle Strength and Maximum Oxygen Uptake in Athletes

2016 ◽  
Vol 50 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Anna Książek ◽  
Aleksandra Zagrodna ◽  
Wioletta Dziubek ◽  
Bogdan Pietraszewski ◽  
Bartosz Ochmann ◽  
...  
Keyword(s):  
Vitamin D ◽  
Muscle Strength ◽  
Oxygen Uptake ◽  
Lower Limb ◽  
Peak Torque ◽  
Maximum Oxygen Uptake ◽  
Soccer Players ◽  
Knee Extensors ◽  
Vitamin D Receptors ◽  
Professional Soccer

AbstractVitamin D is mainly known for its effects on the bone and calcium metabolism. The discovery of Vitamin D receptors in many extraskeletal cells suggests that it may also play a significant role in other organs and systems. The aim of our study was to assess the relationship between 25(OH)D3 levels, lower limb isokinetic strength and maximum oxygen uptake in well-trained professional football players. We enrolled 43 Polish premier league soccer players. The mean age was 22.7±5.3 years. Our study showed decreased serum 25(OH)D3 levels in 74.4% of the professional players. The results also demonstrated a lack of statistically significant correlation between 25(OH)D3 levels and lower limb muscle strength with the exception of peak torque of the left knee extensors at an angular velocity of 150°/s (r=0.41). No significant correlations were found between hand grip strength and maximum oxygen uptake. Based on our study we concluded that in well-trained professional soccer players, there was no correlation between serum levels of 25(OH)D3 and muscle strength or maximum oxygen uptake.

scholarly journals Evaluating injury risk in first and second league professional Portuguese soccer: muscular strength and asymmetry

2016 ◽  
Vol 51 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Alberto Carvalho ◽  
Scott Brown ◽  
Eduardo Abade
Keyword(s):  
Muscle Strength ◽  
Injury Risk ◽  
Dynamic Control ◽  
Peak Torque ◽  
Soccer Players ◽  
Bilateral Asymmetry ◽  
Hamstring Strain ◽  
Professional Soccer ◽  
Maximal Peak ◽  
The Right

AbstractStrength imbalances between the hamstrings and quadriceps are an essential predictor for hamstring strain in soccer. The study aimed to investigate and compare the muscle strength imbalances of professional soccer players of different performance levels. One hundred and fifty nine senior male professional soccer players from first (n = 75) and second league (n = 84) Portuguese clubs participated in this study. Muscle strength was evaluated with a REV9000 isokinetic dynamometer. Maximal peak torque data were used to calculate quadriceps and hamstrings strength during concentric and eccentric actions, bilateral asymmetry, conventional strength ratios and dynamic control ratios. Second league athletes produced slightly lower conventional strength ratios in the right and left legs (ES = 0.22, p = 0.17 and ES = 0.36, p = 0.023, respectively) compared to the first league athletes. No significant differences were found in dynamic control ratios or in bilateral asymmetry among first and second league athletes. These findings do not show a clear link between the competitive level and injury risk in soccer players. However, some of the differences found, particularly in conventional strength ratios, highlight the importance of performing off-season and pre-season strength assessments to prescribe and adjust individual strength training programs among professional soccer players.

scholarly journals Comparação de dois critérios de classificação de jogadores de futebol profissional da assimetria lateral de força dos membros inferiores

2017 ◽  
Vol 19 (6) ◽  
pp. 644-651 ◽  
Author(s):  
Sílvia Ribeiro Santos Araujo ◽  
Fabiola Bertu Medeiros ◽  
Alvaro Dressler Zaidan ◽  
Eduardo Mendonça Pimenta ◽  
Edgardo Alvares de Campos Abreu ◽  
...  
Keyword(s):  
General Population ◽  
Confidence Interval ◽  
Peak Torque ◽  
Cutoff Point ◽  
Soccer Players ◽  
Knee Extensors ◽  
Lateral Asymmetry ◽  
Professional Soccer ◽  
Isokinetic Test ◽  
Cutoff Points

Prospective studies have indicated that assessing muscle function by the isokinetic test in the preseason is able to identify muscle strength variables that can be associated with injuries in the hamstring muscles of professional soccer players. However, the results are conflicting and could be related to the different cutoff points for the categorization of athletes in asymmetric or symmetric. Based on these conflicting results, the present study aims to: i) Identify the cutoff points of lateral asymmetry (LA) of the 95% confidence interval for the peak torque in soccer players, evaluated by the isokinetic test, taking into consideration the mean population value; ii) Compare LA between 15% cutoff point proposed in literature and the upper limit of 95% confidence interval (UP) of the study population. Sixty-four professional soccer players performed five knee flexion and extension repetitions at rate of 60°/s, with a one-minute interval. To determine the cutoff point for strength asymmetries, the UP was used, and for the purpose of diagnostic concordance of information among the different values, the McNemar’s χ² test was applied. The proportion between symmetric and asymmetric athletes was not different from the 15% cutoff point and the general population, both for knee flexors (χ² = 0.5, p = 0.250) and the knee extensors (χ² = 2.0, p = 0.125). It was concluded that the cutoff point of 15% referenced in literature for the general population provides similar diagnostic information for the classification of professional soccer players. 

scholarly journals The effects of immersion cryotherapy on levels of muscle strength and power

2020 ◽  
Vol 19 (4) ◽  
pp. 283
Author(s):  
Andre Luiz Lopes ◽  
Júlia Da Silveira Gross ◽  
Renata Lopes Krüger ◽  
Gustavo Dos Santos Ribeiro ◽  
Régis Radaelli ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Lower Limb ◽  
Recovery Of Function ◽  
Peak Torque ◽  
Isometric Strength ◽  
Lower Limbs ◽  
Knee Extensors ◽  
Active Recovery ◽  
Cross Sectional ◽  
Fatigue Protocol

Aims: To verify the influence of immersion cryotherapy on isometric strength and lower limb power of athletes. Methods: Using a cross-sectional crossover design, 14 rugby athletes underwent three laboratory visits. The first visit was composed of anthropometric (mass, height, and body composition), aerobic capacity (cardiopulmonary exercise test), and dietary assessments. On the second and third visits, vertical jump and isometric peak torque of the knee extensors were assessed in three moments: 1) at baseline; 2) after fatigue protocol; and 3) after recovery protocol: active rest or immersion cryotherapy. Fatigue protocol was composed by running at a speed corresponding to 120% of VO2MAX until voluntary fatigue. To immersion cryotherapy, all subjects had their lower limbs immersed in a tank with ice and water (10 ± 1°C), remaining in the standing position for 10 minutes. For active recovery, subjects were standing in an empty tank. Data were analyzed on GraphPAD Prism (p<0.05). Results: Fourteen rugby athletes (age 22 ± 2 years; fat mass 27.8 ± 4.4%; VO2MAX 44.1 ± 6.7 ml.kg-1.min-1) were evaluated. There was no difference in caloric intake among the evaluation days (2,893 ± 802 versus 2,915 ± 746 kcal; p=0.949). Jump height reduced 18% after fatigue and immersion cryotherapy protocols (33.0 ± 2.8 versus 27.0 ± 2.8 cm; p<0.05) and a 7.1% increase after fatigue and active rest (32.5 ± 6.4 versus 34.8 ± 2.1 cm; p<0.05). Regarding the isometric peak torque, it was reduced by 3.7% after immersion cryotherapy (295 ± 71 versus 285 ± 68 Nm; p<0.05) and 9.6% after active rest (297 ± 73 versus 268 ± 72 Nm; p<0.05). Conclusion: Immersion cryotherapy seems to affect lower limb power albeit could assist in the recovery of isometric strength compared to passive recovery. This information is important to compose recovery protocols for specific tasks.Keywords: physical therapy specialty, cryotherapy, recovery of function, regeneration, muscle strength, athletic performance, exercise.

scholarly journals Lower-Limb Muscle Strength, Anterior-Posterior and Inter-Limb Asymmetry in Professional, Elite Academy and Amateur Soccer Players

2021 ◽  
Vol 77 (1) ◽  
pp. 135-146
Author(s):  
Marco Beato ◽  
Damien Young ◽  
Adam Stiff ◽  
Giuseppe Coratella
Keyword(s):  
Muscle Strength ◽  
Injury Prevention ◽  
Lower Limb ◽  
Peak Torque ◽  
Soccer Players ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Cross Sectional ◽  
Strength Asymmetry ◽  
And Performance

Abstract Given the importance of the lower-limb strength and strength balance in soccer players and its relationship with injury prevention and performance, the present study compared quadriceps and hamstrings strength, the conventional (Hconc:Qconc), functional (Hecc:Qconc) hamstrings-to-quadriceps ratio and inter-limb strength asymmetry in professional, elite academy and amateur male soccer players. In this cross-sectional study, two hundred-six soccer players (professional = 75, elite academy = 68, amateurs = 63) volunteered to participate. Quadriceps and hamstrings isokinetic peak torque was investigated at 60° .s-1 in both the concentric and eccentric modality and at 300°.s-1 in the concentric modality. The conventional Hconc:Qconc, functional Hecc:Qconc ratio and quadriceps and hamstrings inter-limb strength asymmetry were then calculated. Professional players presented greater quadriceps and hamstrings strength than elite academy (effect size from small to moderate) and amateur players (moderate to very large). Both the conventional Hconc:Qconc and functional Hecc:Qconc ratio were greater in professional than elite academy and amateur players (small to moderate). Overall, quadriceps and hamstrings inter-limb strength asymmetry was greater in amateurs than professional (small to very large) and elite academy (trivial to large) players. The present findings provide coaches and medical staffs with normative lower-limb muscle strength data on professional, academy and amateur soccer players. Overall lower-limb muscle strength and inter-limb strength asymmetry could be used to evaluate possible inference on injury prevention and performance. The hamstrings-to-quadriceps ratio poorly differentiates between the soccer players background and offers limited prediction for injury prevention and performance.

scholarly journals Influence of Fatigue on the Rapid Hamstring/Quadriceps Force Capacity in Soccer Players

2021 ◽  
Vol 12 ◽  
Author(s):  
Qingshan Zhang ◽  
Baptiste Morel ◽  
Robin Trama ◽  
Christophe A. Hautier
Keyword(s):  
Injury Risk ◽  
Muscle Activation ◽  
Statistical Parametric Mapping ◽  
Peak Torque ◽  
Frequency Component ◽  
Surface Emg ◽  
Knee Extension ◽  
Soccer Players ◽  
Knee Extensors ◽  
Professional Soccer

The objective of this study was to examine the effect of fatigue on maximal and rapid force capacities and muscular activation of the knee extensors and flexors. Seventeen professional soccer players volunteered to participate in this study. Peak torque (Tpeak) and rate of torque development (RTD) of knee flexor (90°. s–1, −30°. s–1) and extensor (90°. s–1) muscles were measured before and after fatigue (i.e., 30 maximal knee extension and flexion repetitions at 180°s–1) performed on an isokinetic dynamometer. Hamstring to quadriceps peak strength and RTD ratios were calculated. Besides, using surface EMG, the mean level of activation (RMSmean), Rate of EMG Rise (RER), and EMG Frequency-Time maps were measured on quadriceps and hamstring muscles. Following fatigue, Tpeak, RTD, RER declined significantly in the two muscle groups (all p &lt; 0.05) without modification of RMSmean. No decrease in conventional and functional H/Q ratios was observed after fatigue except for a significant increase in the Hecc30/Qcon180 ratios (1.03 ± 0.19 vs. 1.36 ± 0.33, p &lt; 0.001). Besides, the RTD H/Q ratios decreased significantly after fatigue, and the statistical parametric mapping analysis (SPM) performed on the EMG/angle curves, and EMG Frequency-Time maps showed that fatigue strongly influenced the muscle activation during the first 100 ms of the movement, following the higher EMG frequency component shift toward the lower frequency component. Our results show that the reduction of RTD and RER during the first 100 ms of the contraction after fatigue exercise makes more sense than any H/Q ratio modification in understanding injury risk in soccer players.

scholarly journals Reduced Lower-Limb Muscle Strength and Volume in Patients With Type 2 Diabetes in Relation to Neuropathy, Intramuscular Fat, and Vitamin D Levels

Diabetes Care ◽  
2016 ◽  
Vol 39 (3) ◽  
pp. 441-447 ◽  
Author(s):  
Monirah M. Almurdhi ◽  
Neil D. Reeves ◽  
Frank L. Bowling ◽  
Andrew J.M. Boulton ◽  
Maria Jeziorska ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Vitamin D ◽  
Muscle Strength ◽  
Lower Limb ◽  
Intramuscular Fat ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Vitamin D Levels

scholarly journals Morphological Changes of the Hip Commonly Associated With Femoroacetabular Impingement Are Not Correlated With Rotational Range of Hip Motion in Elite Soccer Athletes

2021 ◽  
pp. 194173812097366
Author(s):  
André Orlandi Bento ◽  
Guilherme Falótico ◽  
Keelan Enseki ◽  
Ronaldo Alves Cunha ◽  
Benno Ejnisman ◽  
...  
Keyword(s):  
Femoroacetabular Impingement ◽  
Lower Limb ◽  
Clinical Relevance ◽  
Morphological Changes ◽  
Alpha Angle ◽  
Soccer Players ◽  
Level Of Evidence ◽  
Rotational Movement ◽  
Professional Soccer ◽  
Significant Difference

Background: Morphological changes characteristic of femoroacetabular impingement (FAI) are common in soccer players. However, the clinical relevance of such anatomical variations is still not well-defined. Hypothesis: We hypothesized that high alpha angle values and/or acetabular retroversion index (ARI) are correlated with rotational range of motion (ROM) of the hip and that there are clinical-radiological diferences between the dominant lower limb (DLL) and nondominant lower limb (NDLL) in professional soccer players. Study Design: Cross-sectional. Level of Evidence: Level 3. Methods: A total of 59 male professional soccer players (average age 25.5 years, range 18-38 years) were evaluated in the preseason. As main outcome measures, we evaluated the alpha angle and the ARI and hip IR and ER ROM with radiographic analysis. Results: The measurements taken on DLL and NDLL were compared and a significant difference was found between the sides in the ER ( P = 0.027), where the DLL measures were 1.54° (95% CI, 0.18-2.89) greater than the NDLL. There were no significant differences between the sides in the measures of IR ( P > 0.99), total ROM ( P = 0.07), alpha angle ( P = 0.250), and ARI ( P = 0.079). The correlations between the rotation measurements and the alpha angle in each limb were evaluated and the coefficient values showed no correlation; so also between the ARI and rotation measures. Conclusion: Morphological changes of the femur or acetabulum are not correlated with hip IR and ER ROM in male professional soccer players. ER on the dominant side was greater than on the nondominant side. There was no significant difference in the other measurements between sides. Clinical Relevance: In clinical practice, it is common to attribute loss of hip rotational movement to the presence of FAI. This study shows that anatomical FAI may not have a very strong influence on available hip rotational movement in professional soccer athletes.

scholarly journals ISOKINETIC PROFILES AND REFERENCE VALUES OF PROFESSIONAL SOCCER PLAYERS

2021 ◽  
Vol 27 (6) ◽  
pp. 610-615
Author(s):  
Guillermo Charneco Salguero ◽  
Francisco García-Muro San José ◽  
Arturo Pérez Gosalvez ◽  
Jose Miguel Cárdenas Rebollo ◽  
Isabel Brígido Fernández ◽  
...  
Keyword(s):  
Reference Values ◽  
Health Professionals ◽  
High Speed ◽  
Peak Torque ◽  
Soccer Players ◽  
Level Of Evidence ◽  
Warm Up ◽  
Professional Soccer ◽  
Average Work ◽  
Torque Values

ABSTRACT Introduction: Isokinetics is a tool commonly used in professional soccer. There is ongoing debate among researchers as to the isokinetic reference values a player should have. Objectives: To determine the absolute peak torque (PT) and average work of professional soccer players in relation to their positions on the field, and to establish the reference values for these variables. Methods: Purposeful sampling was used to select 289 professional soccer players. The sample included 32 goalkeepers, 100 defenders, 98 midfielders, and 59 strikers. The participants were measured preseason. The players were asked to perform a 10-minute warm-up on an exercise bike, and then to perform 5 repetitions at low speed, 10 at medium speed, and 25 at high speed, with 30 to 40-s of rest between each set of repetitions. The contraction method was concentric-concentric in a dynamometer Isomed 2000. Results: The average age, weight, and height of the players was 21.9 years, 74.3 kilograms, and 1.8 meters, respectively. The goalkeepers presented higher PT at the 3 measured speeds, and the higher average work at 180°/s and 240°/s in relation to defenders and midfielders. The strikers presented higher average work at 240°/s in relation to midfielders, and higher PT in relation to the defenders and midfielders. Absolute values were shown and reference values were established. Conclusions: The goalkeepers and strikers were the players that showed the greatest differences in their favor in relation to the other positions. The peak torque values and average work were described in relation to the player's position on the field. This study resulted in the creation of a tool for health professionals working with professional soccer players, providing reference values for these players in relation to their position on the field that can be used as benchmarks, by health professionals, to optimize soccer players’ performance. Level of evidence II, Prospective comparative study.

scholarly journals Development of Lower Extremity Strength in Ambulatory Children With Bilateral Spastic Cerebral Palsy in Comparison With Typically Developing Controls Using Absolute and Normalized to Body Weight Force Values

2021 ◽  
Vol 12 ◽  
Author(s):  
Nicolaos Darras ◽  
Eirini Nikaina ◽  
Magda Tziomaki ◽  
Georgios Gkrimas ◽  
Antigone Papavasiliou ◽  
...  
Keyword(s):  
Body Weight ◽  
Cerebral Palsy ◽  
Muscle Strength ◽  
Lower Limb ◽  
Age Groups ◽  
Knee Extensors ◽  
Spastic Cerebral Palsy ◽  
Typically Developing ◽  
Antagonist Muscles ◽  
Muscle Groups

This cross-sectional study aimed to examine the development of lower limb voluntary strength in 160 ambulatory patients with bilateral spastic cerebral palsy (CP) (106 diplegics/54 quadriplegics) and 86 typically developing (TD) controls, aged 7–16 years. Handheld dynamometry was used to measure isometric strength of seven muscle groups (hip adductors and abductors, hip extensors and flexors, knee extensors and flexors, and ankle dorsiflexors); absolute force (AF) values in pounds were collected, which were then normalized to body weight (NF). AF values increased with increasing age (p &lt; 0.001 for all muscle groups), whereas NF values decreased through adolescence (p &lt; 0.001 for all muscle groups except for hip abduction where p = 0.022), indicating that increases in weight through adolescence led to decreases in relative force. Both AF and NF values were significantly greater in TD subjects when compared with children with CP in all muscle and all age groups (p &lt; 0.001). Diplegics and quadriplegics demonstrated consistently lower force values than TD subjects for all muscle groups, except for the hip extensors where TD children had similar values with diplegics (p = 0.726) but higher than quadriplegics (p = 0.001). Diplegic patients also exhibited higher values than quadriplegics in all muscles, except for the knee extensors where their difference was only indicative (p = 0.056). The conversion of CP subjects' force values as a percentage of the TD subjects' mean value revealed a pattern of significant muscle strength imbalance between the CP antagonist muscles, documented from the following deficit differences for the CP muscle couples: (hip extensors 13%) / (hip flexors 32%), (adductors 27%) / (abductors 52%), and (knee extensors 37%) / (knee flexors 53%). This pattern was evident in all age groups. Similarly, significant force deficiencies were identified in GMFCS III/IV patients when compared with TD children and GMFCS I/II patients. In this study, we demonstrated that children and adolescents with bilateral CP exhibited lower strength values in lower limb muscles when compared with their TD counterparts. This difference was more prevalent in quadriplegic patients and those with a more severe impairment. An important pattern of muscle strength imbalance between the antagonist muscles of the CP subjects was revealed.

Sign in / Sign up

Export Citation Format

Share Document