scholarly journals Effect of long-term training adaptation on isokinetic strength in college male volleyball players

2019 ◽  
Vol 23 (5) ◽  
pp. 236-241
Author(s):  
A. Kafkas ◽  
M.E. Kafkas ◽  
S. Savaş
Keyword(s):  
Resistance Training ◽  
Muscle Strength ◽  
Knee Extensor ◽  
Isokinetic Strength ◽  
Flexor Muscle ◽  
Knee Strength ◽  
Volleyball Players ◽  
Angular Velocities ◽  
Knee Muscle ◽  
Flexor Strength

Background and Study Aim: Most of this study focused on endurance, power, and anthropometric measurements but no research declared isokinetic strength changes during two years. The purpose of this study was to assess the effect of resistance exercises on two seasonal alters in isokinetic strength of knee muscles at different angular velocities, in college volleyball players. Material and Methods: Thirteen college volleyball players, (age: 21.75 years, body mass: 78.60 kg, and height: 187.0 cm) participated in the study. All college volleyball players take part in the two-year (8 month each year) volleyball-specific training and competitions. The measurement of peak isokinetic concentric knee extension and knee flexion torque in both legs were taken at 2 angular velocities of movement, low at 60° s-1, and intermediate at 180° s-1. Results: The pre- and post-test values of the peak isokinetic strength found that statistical significance difference, at 60° s-1 and 180° s-1 for knee extensor-flexor both dominant and non-dominant in favor of post-tests. Significant enhances were observed in the baseline dominant knee extensor-flexor muscle strength (extensor knee strength 60° s-1: 19.0%, 180° s-1: 20.5%, flexor knee strength, 60° s-1: 33.4%, 180° s-1: 31.4%) respectively. Non-dominant knee extensor-flexor muscle strength increased significantly over the two-year period (extensor knee strength 60° s-1: 21.3%, 180° s-1: 23.0%, flexor knee strength, 60° s-1: 37.4%, 180° s-1: 33.9%) respectively. Conclusion: As a result, our data suggests that the two-year planned program of specific volleyball and resistance training can increase the knee muscle extensor-flexor strength and H:Q ratios of volleyball players. Especially, at a 60° s-1 and 180° s-1 angular velocities, whilst the knee muscle extensor-flexor strength and H:Q ratios for dominant and non-dominant legs were increasing, also H:Q ratios disproportion were decreasing. Therefore, these alters indicated that regular specific-volleyball and resistance training can increase knee muscle extensor-flexor strength and H:Q ratios for dominant and non-dominant legs.

Isokinetic Strength After ACL Reconstruction: Influence of Concomitant Anterolateral Ligament Reconstruction

2021 ◽  
pp. 194173812110054
Author(s):  
Benoit Gillet ◽  
Yoann Blache ◽  
Isabelle Rogowski ◽  
Grégory Vigne ◽  
Bertrand Sonnery-Cottet ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Ligament Reconstruction ◽  
Knee Extensor ◽  
Anterolateral Ligament ◽  
Flexor Muscle ◽  
Knee Flexor ◽  
Strength Recovery ◽  
Flexor Muscles ◽  
Knee Muscle ◽  
Knee Muscle Strength

Background: To reduce the rate of anterior cruciate ligament (ACL) graft rupture, recent surgeries have involved anterolateral ligament reconstruction (ALLR). This reconstruction procedure harvests more knee flexor muscle tendons than isolated ACL reconstruction (ACLR), but its influence on knee muscle strength recovery remains unknown. This study aimed to assess the influence of ALLR with a gracilis graft on the strength of the knee extensor and flexor muscles at 6 months postoperatively. Hypothesis: The additional amount of knee flexor harvest for ALLR would result in impairment in knee flexor muscle strength at 6 months postoperatively. Study Design: Retrospective cohort study. Level of Evidence: Level 2. Methods: A total of 186 patients were assigned to 2 groups according to the type of surgery: ACL + ALLR (graft: semitendinosus + gracilis, n = 119) or isolated ACLR (graft: semitendinosus, n = 67). The strength of the knee extensor and flexor muscles was assessed using an isokinetic dynamometer at 90, 180, and 240 deg/s for concentric and 30 deg/s for eccentric contractions and compared between groups using analysis of variance statistical parametric mapping. Results: Regardless of the surgery and the muscle, the injured leg produced significantly less strength than the uninjured leg throughout knee flexion and extension from 30° to 90° for each angular velocity (30, 90, 180, and 240 deg/s). However, the knee muscle strength was similar between the ACL + ALLR and ACLR groups. Conclusion: The addition of ALLR using the gracilis tendon during ACLR does not alter the muscle recovery observed at 6 months postoperatively. Clinical Relevance: Although more knee flexor muscle tendons were harvested in ACL + ALLR, the postoperative strength recovery was similar to that of isolated ACLR.

Hamstring Flexibility Is Not Correlated with Isokinetic Knee Muscle Strength in Female Modern Dancers

2018 ◽  
Vol 33 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Ani Agopyan
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Flexor Muscle ◽  
Work Production ◽  
University Level ◽  
Modern Dancers ◽  
Hamstring Flexibility ◽  
Knee Muscle ◽  
The Right

OBJECTIVE: To evaluate bilateral isokinetic knee extensor and flexor muscle strength relative to hamstring flexibility in female modern dancers. METHODS: 20 trained university-level female modern dance students (mean age 23.8±3.8 yrs) volunteered for the study. Concentric isokinetic peak torque (PT, in Nm), peak torque % of body weight (PT%BW, in Nm/kg), and total work (TW, in J) of the knee extensor and flexor muscles for each leg were measured with a dynamometer at a velocity of 60, 180, and 300°/s. Hamstring flexibility of both limbs was assessed by a goniometer with the subjects in a supine position using the active straight leg raise (SLR) test. Participants were divided into flexible (n=10) and highly flexible (n=10) groups based on their hamstring flexibility. RESULTS: The flexible and highly flexible groups had significant differences (p≤0.05) for the right (flexible, 119.7±4.3°; highly flexible, 137.7±2.6°) and left active SLR tests (flexible, 120.6±5.3°; highly flexible, 138.3±4.5°). No significant differences were found between the flexible and highly flexible dancers for concentric knee extensor and flexor muscle strength in all selected parameters (p≤0.05). There were also no significant correlations between flexibility and bilateral PT, PT%BW, and TW scores (60, 180, and 300°/s) of dancers at the concentric contraction (p≤0.05). CONCLUSION: These findings indicate that hamstring flexibility (for both the flexible and highly flexible groups) is not correlated with knee strength and has no impact on torque and work production during maximal concentric isokinetic knee muscle action in university-level female modern dancers.

scholarly journals Velocity-specific knee strength between professional and under-17 female volleyball player

2019 ◽  
Vol 75 (1) ◽  
Author(s):  
Alexandre R.M. Pelegrinelli ◽  
Laís F. Dela Bela ◽  
Mariana F. Silva ◽  
Lucas C.R. Rodrigues ◽  
João P. Batista ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Total Work ◽  
Flexor Muscle ◽  
Mean Power ◽  
Cross Sectional ◽  
Significant Group ◽  
Surface Maps ◽  
Volleyball Players

Background: Many studies have investigated isokinetic performance in volleyball players but not through surface maps.Objectives: The goals of this study were to assess velocity-specific isokinetic knee extensor–flexor muscle strength and to compare the isokinetic knee extensor–flexor muscles between professional (PRO) and under-17 (U17) female volleyball players.Method: This cross-sectional laboratory study was developed with two groups: PRO (n = 12), medianage = 21.3 years, and U17 (n = 9), medianage = 15 years. Peak torque, total work, mean power, angle of peak torque, hamstring–quadriceps torque ratio (H–Q ratio) and torque–angle–velocity surface maps were analysed from knee extension–flexion at 60, 120 and 300 degrees per second (°/s).Results: Significant differences were identified for extensor peak torque between PRO x = 202.3 Newton metre (N·m) (standard deviation [SD] = 24.4) and U17 x = 141.6 N·m (30.1) at 60 °/s (p < 0.001; d = 2.21) as well as flexor peak torque (PRO x = 75.7 N·m [10.3] and U17 x = 57.7 N·m [11.4]) at 120 °/s (p < 0.001; d = 1.65) for the dominant limb. There were also significant group differences for total work and mean power at all velocities for extension and flexion. Surface maps demonstrated higher torque at lower speeds for both groups with smaller torque changes across velocities for flexion.Conclusion: Different groups of female volleyball players showed contrasting concentric knee muscle strength across isokinetic velocities.Clinical implications: These results demonstrate the importance of specific strength training for different age groups, even within the same sport, and provide insight into muscle strength.

scholarly journals Isokinetic Strength Responses to Season-long Training and Competition in Turkish Elite Soccer Players

2012 ◽  
Vol 31 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Niyazi Eniseler ◽  
Çağatay Şahan ◽  
Hikmet Vurgun ◽  
Hasan Mavi
Keyword(s):  
Knee Extensor ◽  
Peak Torque ◽  
Soccer Players ◽  
Isokinetic Strength ◽  
Professional Soccer ◽  
Knee Strength ◽  
Flexor Muscles ◽  
Angular Velocities ◽  
Soccer Training ◽  
Knee Flexors

Isokinetic Strength Responses to Season-long Training and Competition in Turkish Elite Soccer PlayersThere are not enough studies that describe the isokinetic strength of professional soccer players at high angular velocities. The purpose of this study was to evaluate the seasonal changes in isokinetic strength of Turkish professional soccer players (n=14) over the course of a 24-week soccer season. The isokinetic strength of players who underwent usual soccer training and weekly competition throughout the soccer season was assessed by means of the Biodex System 3 dynamometer with the knee attachment. The peak torque of knee extensor and flexor muscles were measured at angular velocities of 60°/s, 300°/s and 500°/s. Players were tested at the beginning and end of the competitive season. While the first- and second-test measurements did not show significant changes at 60°/s and 300°/s angular velocities, at the end of the training period, players' knee strength changed significantly at 500°/s angular velocities. In addition, the H/Q ratio improved significantly for the dominant as well as non-dominant leg at 500°/s. Significant bilateral strength improvements for knee flexors were also observed at 500°/s. The findings of this study suggest that usual daily soccer training (technical, tactical, power, strength, endurance, flexibility, etc.) and weekly competition might produce changes in knee strength at high angular velocities.

scholarly journals The relationship between upper leg muscle strength and walking capacity in persons with multiple sclerosis

2012 ◽  
Vol 19 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Tom Broekmans ◽  
Domien Gijbels ◽  
Bert O. Eijnde ◽  
Geert Alders ◽  
Ilse Lamers ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Resistance Training ◽  
Muscle Strength ◽  
Knee Extensor ◽  
Knee Extensors ◽  
Regression Analyses ◽  
Walking Capacity ◽  
Disability Status ◽  
Leg Muscle ◽  
Flexor Strength

Background: In persons with multiple sclerosis (PwMS) resistance training improves muscle strength but effects on walking capacity are inconsistent. Objective: The objective was to determine the relation between different types of upper leg muscle strength measurements and walking capacity in PwMS. Methods: An observational cross-sectional study design was applied. Upper leg muscle strength of 52 PwMS (Expanded Disability Status Scale, EDSS range 1.5–6.5) was measured using isometric (knee extensors and flexors) and isokinetic (knee extensors) dynamometry. Walking capacity was assessed using the Timed 25-Foot Walk, Timed Up and Go and Two Minute Walk Test. Subgroups with mild (EDSS 1.5–4.0, n=31) and moderate (EDSS 4.5–6.5, n=21) ambulatory dysfunction were distinguished, and results were hypothesized to differ depending on multiple sclerosis (MS)-related disability status. Correlation and regression analyses were performed on the data of the most affected leg. Results: Greatest ( r: 0.2–0.7) and significant Pearson correlation coefficients were found in the moderate compared to mild MS subgroup. Within knee extensor measurements, it was found that isokinetic endurance strength related best to walking capacity. When comparing maximal isometric strength measurements, knee flexors ( r: 0.5–0.7) related better to walking capacity than knee extensors ( r: 0.1–0.4). Regression analyses confirmed endurance knee extensor strength (~25 %) and isometric knee flexor strength (~40%) as main predictors for walking capacity. Conclusion: Resistance training protocols may consider inclusion of exercises focusing on endurance knee extensor and isometric knee flexor strength when aiming to enhance walking capacity in persons with moderate ambulatory dysfunction.

scholarly journals The Comparison of Lower Extremity Isokinetic Strength in Volleyball Players According to the Leagues

2018 ◽  
Vol 8 (4) ◽  
pp. 111
Author(s):  
Cengiz Akarcesme ◽  
Sinem Hazir Aytar
Keyword(s):  
Lower Extremity ◽  
T Test ◽  
Isokinetic Strength ◽  
Extensor Muscles ◽  
Volleyball Players ◽  
Angular Velocities ◽  
Strength Difference ◽  
Knee Muscle

The purpose of the study is to compare the ratio of lower extremity isokinetic hamstring/quadriceps ratio (H/Q),bilateral strength difference (BLD) and relative peak torques (RPT) in volleyball players according to the leagues.101 volleyball players participated in the study (female=34, male=25 from 1st league; female=21, male=21 from 2ndleague). Isokinetic extension and flexion of knee muscle strengths of the volleyball players were determined withisokinetic dynamometer. Independent t test was used to compare volleyball players' flexor and extensor RPT, H/Qratios and BLD according to their leagues. In the study conducted, it was determined that both male and femalevolleyball players playing the 1st league had higher RPTs at 60°s-1 and 180°s-1 angular velocities. It was determinedthat volleyball players’ BLD was within the desired limits, whereas their H/Q ratios were low. As a result, it wasdetermined that the lower extremity isokinetic knee muscle RPT of the volleyball players playing in the 1st Leaguehad better values than those playing in the 2nd league, but these values were higher in the extension RPT. Since theessential requirement of volleyball is the jumping strength of the movements, this case may be related to the greaterdevelopment of the extensor muscles.

scholarly journals Associations of the Stair Climb Power Test With Muscle Strength and Functional Performance in People With Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

2010 ◽  
Vol 90 (12) ◽  
pp. 1774-1782 ◽  
Author(s):  
Marc Roig ◽  
Janice J. Eng ◽  
Donna L. MacIntyre ◽  
Jeremy D. Road ◽  
W. Darlene Reid
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Muscle Strength ◽  
Functional Performance ◽  
Knee Extensor ◽  
Chronic Obstructive ◽  
Flexor Muscle ◽  
Cross Sectional ◽  
Obstructive Pulmonary Disease ◽  
Power Test ◽  
Muscle Torque

Background The Stair Climb Power Test (SCPT) is a functional test associated with leg muscle power in older people. Objective The purposes of this study were to compare the results of the SCPT in people with chronic obstructive pulmonary disease (COPD) and people who were healthy and to explore associations of the SCPT with muscle strength (force-generating capacity) and functional performance. Design The study was a cross-sectional investigation. Methods Twenty-one people with COPD and a predicted mean (SD) percentage of forced expiratory volume in 1 second of 47.2 (12.9) and 21 people who were healthy and matched for age, sex, and body mass were tested with the SCPT. Knee extensor and flexor muscle torque was assessed with an isokinetic dynamometer. Functional performance was assessed with the Timed “Up & Go” Test (TUG) and the Six-Minute Walk Test (6MWT). Results People with COPD showed lower values on the SCPT (28%) and all torque measures (∼32%), except for eccentric knee flexor muscle torque. In people with COPD, performance on the TUG and 6MWT was lower by 23% and 28%, respectively. In people with COPD, the SCPT was moderately associated with knee extensor muscle isometric and eccentric torque (r≥.46) and strongly associated (r=.68) with the 6MWT. In people who were healthy, the association of the SCPT with knee extensor muscle torque tended to be stronger (r≥.66); however, no significant relationship between the SCPT and measures of functional performance was found. Limitations The observational design of the study and the use of a relatively small convenience sample limit the generalizability of the findings. Conclusions The SCPT is a simple and safe test associated with measures of functional performance in people with COPD. People with COPD show deficits on the SCPT. However, the SCPT is only moderately associated with muscle torque and thus cannot be used as a simple surrogate for muscle strength in people with COPD.

scholarly journals Effects of resistance training on self-reported disability in older adults with functional limitations or disability – a systematic review and meta-analysis

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Pia Øllgaard Olsen ◽  
Anne-Ditte Termannsen ◽  
Maja Bramming ◽  
Mark A. Tully ◽  
Paolo Caserotti
Keyword(s):  
Older Adults ◽  
Resistance Training ◽  
Muscle Strength ◽  
Functional Capacity ◽  
Meta Analysis ◽  
Functional Limitations ◽  
Knee Extensor ◽  
Objective Measures ◽  
Lower Body ◽  
Positive Effect

Abstract Background Self-reported disability has a strong negative impact on older people’s quality of life and is often associated with the need for assistance and health care services. Resistance training (RT) has been repeatedly shown to improve muscle function (e.g. strength) and functional capacity (e.g. gait speed, chair-rise) in older adults with functional limitations. Nevertheless, it is unclear whether such objectively assessed improvements translate into a reduction in self-reported disability. Objectives To assess: i) whether and to what extent RT interventions have an effect on self-reported disability in older adults (≥65 years) with functional limitations or disability; and ii) whether the effects on self-reported disability are associated with changes in objective measures of muscle strength and functional capacity across studies. Methods PubMed, Embase, Web of Science, CINAHL and SPORTDiscus electronic databases were searched in June 2018. Randomized controlled trials reporting effects of RT on self-reported disability/function in ≥65 year-old adults with defined, functional limitations or self-reported disability were eligible. Data on self-reported disability/function were pooled by calculating adjusted standardized mean differences (SMD) using Hedges’g. Likewise, effect sizes for three secondary outcomes: knee extensor muscle strength; gait capacity; and lower body functional capacity were calculated and fit as covariates in separate meta-regressions with self-reported disability as the dependent factor. Results Fourteen RCTs were eligible for the primary meta-analysis on self-reported disability. The total number of participants was 651 (intervention n = 354; control n = 297). A significant moderate positive effect of RT was found (SMD: 0.59, 95% CI: 0.253 to 0.925, p = 0.001). Between-study heterogeneity was present (I2 statistic = 75,1%, p <  0.001). RT effects on objective measures of lower body functional capacity were significantly associated with effects on self-reported disability (Adj. R2 = 99%, p = 0.002, n = 12 studies), whereas no significant associations with gait capacity or knee extensor strength were found. Conclusions This review provides evidence that RT has a moderate positive effect on self-reported disability/function in old people with or at risk for disability. The effects are strongly associated with effects on objective measures of lower body functional capacity.

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