scholarly journals Temporal Patterns of Knee-Extensor Isokinetic Torque Strength in Male and Female Athletes Following Comparison of Anterior Thigh and Knee Cooling Over a Rewarming Period

2020 ◽  
Vol 29 (6) ◽  
pp. 723-729
Author(s):  
Jill Alexander ◽  
David Rhodes
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Local Cooling ◽  
Isokinetic Testing ◽  
Time Points ◽  
Anterior Thigh ◽  
Males And Females ◽  
Main Effects ◽  
To Receive

Context: The effect of local cooling on muscle strength presents conflicting debates, with literature undecided as to the potential implications for injury, when returning to play following cryotherapy application. Objective: To investigate concentric muscle strength following local cooling over the anterior thigh compared with the knee joint in males and females and the temporal pattern over a 30-minute rewarming period. Design: Repeated-measures crossover design. Method: Twelve healthy participants randomly assigned to receive cooling intervention on one location, directly over either the anterior thigh or the knee, returning 1 week later to receive the cooling intervention on opposite location. Muscle strength measured via an isokinetic dynamometer at multiple time points (immediately post, 10-, 20-, and 30-min post) coincided with measurement of skin surface temperature (Tsk) using a noninvasive infrared camera. Results: Significant main effects for time (P ≤ .001, η2 = .126) with preice application higher than all other time points (P ≤ .05) were demonstrated for both peak torque and average torque. There were also significant main effects for isokinetic testing speed, sex of the participant, and position of the ice application for both peak torque and average torque (P ≤ .05). Statistically significant decreases in Tsk were reported in both gender groups across all time points compared with preintervention Tsk for the anterior thigh and knee (P < .05). Conclusions: Reductions reported for concentric peak torque and average torque knee-extensor strength in males and females did not fully recover to baseline measures at 30-minute postcryotherapy interventions. Sports medicine practitioners should consider strength deficits of the quadriceps after wetted ice applications, regardless of cooling location (joint/muscle) or gender.

scholarly journals Assessment of Post-Rehabilitation ACL Reconstructed Knees

2020 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Kevin Carlson
Keyword(s):  
Range Of Motion ◽  
Knee Flexion ◽  
Knee Extensor ◽  
Peak Torque ◽  
Isokinetic Strength ◽  
Isokinetic Testing ◽  
Rehabilitation Protocols ◽  
Dependent Variables ◽  
Hop Test ◽  
Main Effects

Background: Understanding objective measures of ACL-reconstructed knee function is important in determining the efficacy of rehabilitation protocols and a patient’s return to activities of daily living and sport activities. Objective: To assess the range of motion (ROM), isokinetic strength (torque) and functional performance measures (hop test) of ACL-reconstructed and ACL-intact knees. Methods: Twelve volunteers (5 females, 7 males) with unilateral ACL injury and reconstruction were given a battery of tests (hop test for distance, knee range of motion, knee extensor isokinetic testing to assess both affected and unaffected lower limb function, flexibility and strength. Main effects and interactions were analyzed by mixed-model repeated measures ANCOVA. Dependent variables included hop test for distance, knee flexion and extension range of motion, and knee extensor isokinetic torque. The independent variables were the intact/reconstructed ACL knee and time from surgery. Sex was the covariate. Results: No statistically significant differences (p>0.05) were found across all dependent variables hop test for distance (P = 0.939), knee flexion (P = 0.576) and extension (P = 0.431) ROM, and knee extensor torque (eccentric P = 0.923 and concentric P = 0.723) for the main effects and interactions of knee (ACL-reconstructed and ACL-intact) and time (0-12 months, 13-24 months, 25-36 months and 37+ months). The covariate, sex, did produce significant differences for the hop test (P < 0.0001) and isokinetic testing (eccentric peak torque P = 0.003 and concentric peak torque P=0.012). Conclusions: Clinicians may consider present rehabilitation protocols to be adequate in developing ROM and isokinetic strength following ACL reconstruction. However, greater improvements in ROM and strength may be achieved over an extended period following ACL reconstruction surgery.

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.

Sex-based differences in skeletal muscle function and morphology with short-term limb immobilization

2005 ◽  
Vol 99 (3) ◽  
pp. 1085-1092 ◽  
Author(s):  
Nobuo Yasuda ◽  
Elisa I. Glover ◽  
Stuart M. Phillips ◽  
Robert J. Isfort ◽  
Mark A. Tarnopolsky
Keyword(s):  
Muscle Strength ◽  
Lean Mass ◽  
Muscle Function ◽  
Knee Extensor ◽  
Quadriceps Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Short Term ◽  
Cross Sectional ◽  
Time Points

The purpose of this study was to determine the effects of short-term (14-day) unilateral leg immobilization using a simple knee brace (60° flexion)- or crutch-mediated model on muscle function and morphology in men (M, n = 13) and women (W, n = 14). Isometric and isokinetic (concentric-slow, 0.52 rad/s and fast, 5.24 rad/s) knee extensor peak torque was determined at three time points (Pre, Day-2, and Day-14). At the same time points, magnetic resonance imaging was used to measure the cross-sectional area of the quadriceps femoris and dual-energy X-ray absorptiometry scanning was used to calculate leg lean mass. Muscle biopsies were taken from vastus lateralis at Pre and Day-14 for myosin ATPase and myosin heavy chain analysis. Women showed greater decreases (Pre vs. Day-14) compared with men in specific strength (N/cm2) for isometric [M = 3.1 ± 13.3, W = 17.1 ± 15.9%; P = 0.055 (mean ± SD)] and concentric-slow (M = 4.7 ± 11.3, W = 16.6 ± 18.4%; P < 0.05) contractions. There were no immobilization-induced sex-specific differences in the decrease in quadriceps femoris cross-sectional area (M = 5.7 ± 5.0, W = 5.9 ± 5.2%) or leg lean mass (M = 3.7 ± 4.2, W = 2.7 ± 2.8%). There were no fiber-type transformations, and the decreases in type I (M = 4.8 ± 5.0, W = 5.9 ± 3.4%), IIa (M = 7.9 ± 9.9, W = 8.8 ± 8.0%), and IIx (M = 10.7 ± 10.8, W = 10.8 ± 12.1%) fiber areas were similar between sexes. These findings indicate that immobilization-induced loss of knee extensor muscle strength is greater in women compared with men despite a similar extent of atrophy at the myofiber and whole muscle levels after 14 days of unilateral leg immobilization. Furthermore, we have described an effective and safe knee immobilization method that results in reductions in quadriceps muscle strength and size.

scholarly journals ACTN3 genotype is associated with muscle phenotypes in women across the adult age span

2008 ◽  
Vol 105 (5) ◽  
pp. 1486-1491 ◽  
Author(s):  
Sean Walsh ◽  
Dongmei Liu ◽  
E. Jeffrey Metter ◽  
Luigi Ferrucci ◽  
Stephen M. Roth
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Fat Free Mass ◽  
Isokinetic Dynamometry ◽  
Adult Age ◽  
Encoding Gene ◽  
Total Body ◽  
Torque Values ◽  
Adult Volunteers

The R577X polymorphism in the α-actinin-3 encoding gene ( ACTN3) has been associated with elite athletic performance, and recently with differences in isometric and dynamic muscle strength and power in the general population. In this study we sought to determine the association of ACTN3 R577X genotype with muscle strength and mass phenotypes in men and women across the adult age span. Eight hundred forty-eight ( n = 848) adult volunteers (454 men and 394 women) aged 22–90 yr were genotyped for ACTN3 R577X. Knee extensor (KE) shortening and lengthening peak torque values were determined using isokinetic dynamometry and fat-free mass (FFM) by dual-energy X-ray absorptiometry. Women deficient in α-actinin-3 (X/X; n = 53) displayed lower KE shortening peak torque (30°/s: 89.5 ± 3.5 vs. 99.3 ± 1.4 N·m, P = 0.011; 180°/s: 60.3 ± 2.6 vs. 67.0 ± 1.0 N·m, P = 0.019) and KE lengthening peak torque (30°/s: 122.8 ± 5.7 vs. 137.0 ± 2.2 N·m, P = 0.022; 180°/s: 121.8 ± 5.8 vs. 138.5 ± 2.2 N·m, P = 0.008) compared with R/X + R/R women ( n = 341). Women X/X homozygotes also displayed lower levels of both total body FFM (38.9 ± 0.5 vs. 40.1 ± 0.2 kg, P = 0.040) and lower limb FFM (11.9 ± 0.2 vs. 12.5 ± 0.1 kg, P = 0.044) compared with R/X + R/R women. No genotype-related differences were observed in men. In conclusion, our results indicate that the absence of α-actinin-3 protein (i.e., ACTN3 X/X genotype) influences KE peak torque and FFM in women but not men.

scholarly journals Resistance training-induced gains in knee extensor strength are related to increased neural cell adhesion molecule expression in older adults with knee osteoarthritis

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas B. Voigt ◽  
Timothy W. Tourville ◽  
Michael J. Falcone ◽  
James R. Slauterbeck ◽  
Bruce D. Beynnon ◽  
...  
Keyword(s):  
Older Adults ◽  
Muscle Strength ◽  
Cell Adhesion Molecule ◽  
Knee Extensor ◽  
Peak Torque ◽  
Neural Adaptations ◽  
Mhc Ii ◽  
Neural Cell Adhesion ◽  
Fiber Size ◽  
Whole Muscle

Abstract Objective Resistance training (RT) can improve whole muscle strength without increasing muscle fiber size or contractility. Neural adaptations, which lead to greater neural activation of muscle, may mediate some of these improvements, particularly in older adults, where motor neuron denervation is common. The purpose of this study was to explore the relationship of neural adaptations, as reflected by neural cell adhesion molecule (NCAM) expression, to improvements in (1) whole muscle strength and (2) muscle fiber size following RT in older adults with knee osteoarthritis. We performed whole muscle strength measurements and immunohistochemical analysis of fiber size, type, and NCAM expression before and after a 14-week RT program. Results RT increased whole-muscle strength as measured by 1-repetition maximum (1-RM) leg press (P = 0.01), leg extension (P = 0.03), and knee extensor peak torque (P = 0.050), but did not alter NCAM expression. Greater NCAM expression in myosin heavy chain (MHC) II fibers was associated with greater whole muscle strength gains (knee extensor peak torque r = 0.93; P < 0.01) and greater MHC II fiber size (r = 0.79; P < 0.01). Our results suggest that training-induced NCAM expression, and neural adaptations more generally, may be important for RT-induced morphological and functional improvements in older adults. Trial registration NCT01190046

scholarly journals Effects of a therapeutic exercises program associated with pompage technique on pain, balance and strength in elderly women with knee osteoarthritis

2017 ◽  
Vol 30 (suppl 1) ◽  
pp. 11-21
Author(s):  
Ihana Thaís Guerra de Oliveira Gondim ◽  
Amanda Bruto da Costa Torres ◽  
Amanda Telino Baudel de Lacerda ◽  
Danielle Queiroz Kühni Fernandes ◽  
Moisés Costa do Couto ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Postural Balance ◽  
Elderly Women ◽  
Intervention Group ◽  
Knee Extensor ◽  
Peak Torque ◽  
Control Group ◽  
Therapeutic Exercise ◽  
Therapeutic Exercises

Abstract Introduction: Knee Osteoarthritis (OA) affects mainly elderly, being characterized by arthralgia, stiffness and strength and balance deficits. Scientific evidence suggests beneficial effects of exercise therapy on these changes, but lacks detailed protocols. In addition, there were published studies on effects of therapeutic exercise associated with pompage that were not located. Objective: To investigate the effects of a therapeutic exercise program associated with pompage on pain, balance and muscle strength in elderly women with knee osteoarthritis. Methods: A randomized pilot clinical trial that included 22 women (60 - 80 years) diagnosed with knee OA, randomized and allocated by simple raffle into two groups: intervention and control. Intervention group (strengthening and balance exercises and knee pompage) performed two sessions per week for 12 weeks. The control group received educational lectures, they were evaluated before and after 12 weeks: arthralgia- subscale pain of the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire (WOMAC); postural stability- postural balance protocol by Biodex Balance SD and muscle strength- concentric peak torque of the knee extensor by isokinetic dynamometer. The Independent Student t test was used for intergroup analysis. Results: The intervention group compared with the control showed better results for the outcomes pain, balance and muscle strength after 12 weeks. However, the difference was statistically significant (p < 0.05) for levels of antero-posterior oscillation (DM -0.28, 95% CI -0.54 a -0.02; p = 0.035) and global oscillation (DM -0.36, 95% CI -0.68 a -0.04; p = 0.028). Conclusion: The intervention had a positive effect on postural balance in elderly women with knee osteoarthritis.

scholarly journals ISOKINETIC PERFORMANCE AND LIMB ASYMMETRY DIFFERENCES BETWEEN ADOLESCENT MALES AND FEMALES FOLLOWING QUADRICEPS TENDON – PATELLAR BONE AUTOGRAFT ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0020
Author(s):  
Alexia G. Gagliardi ◽  
David R. Howell ◽  
Susan K. Kanai ◽  
Jason T. Rhodes ◽  
Alex Tagawa ◽  
...  
Keyword(s):  
Acl Reconstruction ◽  
Return To Sport ◽  
Quadriceps Tendon ◽  
Peak Torque ◽  
Maximum Torque ◽  
Isokinetic Testing ◽  
Text Figure ◽  
Strength Asymmetry ◽  
Males And Females ◽  
Isokinetic Performance

Background: Accurate measurement of limb strength asymmetry differences between sexes may be important to consider when determining readiness to return to sport among adolescents following ACL reconstruction. Hypothesis/Purpose: The purpose was to compare isokinetic performance between females and males after ACL reconstruction but before return to sport clearance on isokinetic measures of limb strength asymmetry and flexor/extensor strength ratio. We hypothesized there would be no difference in limb strength asymmetry or flexor/extensor strength ratio between sexes measured by isokinetic testing. Methods: We retrospectively collected demographic, surgical, and injury information on patients aged 10 – 18 years at time of surgery. Patients completed isokinetic testing within 5-10 months after primary quadriceps tendon ACL reconstruction, and before return to sport clearance. Isokinetic testing assessed maximum torque at three speeds, 60, 180, and 300 degrees per second, through a limited range of knee extension and flexion. Maximum torque percent deficit of the involved leg compared to the uninvolved leg and flexor/extensor strength ratios were calculated. We compared peak torque extensor deficits and flexor deficits (the % difference between operative and non-operative sides) and flexor/extensor ratios at the three isokinetic test speeds within sexes and between sexes. Results: 80 subjects were tested during the study period, of which 44 subjects met inclusion criteria (female: n=29, 66%). Injury characteristics and time since surgery were similar between sexes (Table 1). Greater extensor deficits among males and females were observed at 60 degrees/s compared to 180 degree/s (p=0.003) and 300 degree/s (p<0.001), and at 180 degrees/s compared to 300 degrees/s (p=0.001) (Figure 1). Females demonstrated significantly greater peak torque flexor deficits at 300 degrees/s, compared to males (p=0.04, Figure 2). Within males, greater flexor deficits were observed at 60 degrees/s compared to 180 degrees/s (p<0.001) and 300 degrees/s (p=0.001) (Figure 2). Within females, greater flexor deficits were observed at 60 degrees/s compared to 180 degrees/s (p=0.02, Figure 2). There were no significant interactions or main effects of sex or speed for either the operative or the non-operative limb peak torque flexor/extensor ratio. Conclusion: The results demonstrate greater peak torque flexor deficits among females compared to males at the fastest testing speed in our protocol. Currently, our results indicate variability both within and between sex isokinetic performance at different speeds and suggest that isokinetic testing at slower speeds may be most effective in determining strength deficits between limbs. Tables and Figures: [Table: see text][Figure: see text][Figure: see text]

scholarly journals Effects of Kinesiology Taping on Shoulder Posture and Peak Torque in Junior Baseball Players with Rounded Shoulder Posture: A Pilot Study

Life ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 139
Author(s):  
Hyeong-geun Yun ◽  
Jung-Hoon Lee ◽  
Im-Rak Choi
Keyword(s):  
Pilot Study ◽  
Muscle Strength ◽  
Internal Rotation ◽  
External Rotation ◽  
Peak Torque ◽  
Crossover Design ◽  
Baseball Players ◽  
Shoulder Peak ◽  
Kinesiology Tape ◽  
To Receive

Rounded shoulder posture (RSP) causes an imbalance of the adjacent joints due to the malalignment of the shoulder joint, and thus affects the strength of the muscles surrounding the shoulder. This study aimed to investigate the effect of rounded shoulder taping (RST) on shoulder posture and muscle strength in junior baseball players. Nineteen junior baseball players participated in the study, which used a crossover design at an interval of 1 week. The participants were randomized to receive rounded shoulder taping (RST) and sham kinesiology taping (SKT) using kinesiology tape. RSP was measured using two 12-inch combination squares, and shoulder peak torques were measured by isokinetic equipment. The results showed that RST led to significant changes in RSP (p < 0.05), but no significant changes were observed with SKT (p < 0.05). RST led to significant changes in the peak torques of external rotation and internal rotation of the shoulder (p < 0.05), but no significant changes were observed with SKT (p < 0.05). These results suggest that RST could help to correct RSP and improve peak torque of external and internal rotation of the shoulders of junior baseball players with RSP.

Knee Extensor Muscle Strength and Vertical Jumping Performance Characteristics in Pre- and Post-Pubertal Boys

2001 ◽  
Vol 13 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Mati Pääsuke ◽  
Jaan Ereline ◽  
Helena Gapeyeva
Keyword(s):  
Muscle Strength ◽  
Isometric Force ◽  
Knee Extensor ◽  
Peak Torque ◽  
Extensor Muscle ◽  
Performance Characteristics ◽  
Jumping Performance ◽  
Vertical Jumping ◽  
Pubertal Boys ◽  
Knee Extensor Muscle Strength

Knee extensor muscle strength and vertical jumping performance characteristics were compared between 14 pre-pubertal (11-year-old) and post-pubertal (16-year-old) boys. Post-pubertal boys had greater (p < .05) absolute values of maximal isometric force (MF) and rate of force development (RFD), absolute and body mass-related values of isokinetic peak torque of the knee extensor muscles at angular velocities of 60, 180, and 240° · s−1, as well as jumping height in squat, counter-movement, and drop jumps, than pre-pubertal boys. This study indicated an inability to use the positive effect of stretch-shortening cycle to vertical jumping performance in pre- and post-pubertal boys.

Sign in / Sign up

Export Citation Format

Share Document