scholarly journals Knee Extensor Rate of Torque Development Before and After Arthroscopic Partial Meniscectomy, With Analysis of Neuromuscular Mechanisms

2017 ◽  
Vol 47 (12) ◽  
pp. 945-956 ◽  
Author(s):  
Daniel G. Cobian ◽  
Cameron M. Koch ◽  
Annunziato Amendola ◽  
Glenn N. Williams
Keyword(s):  
Knee Extensor ◽  
Partial Meniscectomy ◽  
Arthroscopic Partial Meniscectomy ◽  
Rate Of Torque Development ◽  
Before And After ◽  
Torque Development

scholarly journals Does the Early and Late Rate of Torque Development, Change in Relation to the Quadriceps Angle?

2019 ◽  
Vol 7 (3S) ◽  
pp. 1
Author(s):  
Ajlan Saç
Keyword(s):  
Lower Extremity ◽  
Knee Injuries ◽  
Knee Extensor ◽  
Myoelectrical Activity ◽  
Rate Of Torque Development ◽  
Q Angle ◽  
Extensor Muscles ◽  
Significant Difference ◽  
Torque Development ◽  
Knee Extensor Muscles

The rate of torque development (RTD), which determines the force that can be developed in the early phase of muscle contraction (0-200 ms), is very important in terms of tracking explosive strength improvement and preventing knee injuries. The purpose of this study was to investigate the relationship of quadriceps angle which affects the structural alignment of the lower extremity with early (0-100 ms) and late (100-200 ms) rate of torque development of the knee extensor muscles and myoelectrical activity. The study was carried out with 38 well-trained male basketball players (mean age: 22.3±2.5 years). The participants were divided into two groups with normal (<11°) and abnormal (>10°) values. RTD was measured in concentric/concentric mode at 60, 120 and 180°/s angular velocities in an isokinetic dynamometer. Surface electromyography (sEMG) was used to determine the myoelectrical activity. When RTD0-100 and RTD100-200 were examined, statistically significant difference was observed at 60 and 120°/s (p<0.05). However, no difference was observed at 180°/s. In addition, sEMG data did not have a statistically significant difference between groups. Negative correlation was found between all RTD at 60, 10 and 180°/s with Q angle (180°/s RTD0-100 r= -0.34, 180°/s RTD100-200 r= -0.35, 120°/s RTD0-100 r= -0.40, 120°/s RTD100-200 r= -0.48, 60°/s RTD0-100 r= -0.55, 60°/s RTD100-200 r= -0.59; p<0.05). There was a negative correlation between the structural differences of the lower extremity and the early and late rate of torque development of the knee extensor muscles. Considering the structural variables, it is thought that it is important to improve the rate of torque development with appropriate resistance training in athletes with variables such as abnormal Q angle, and thus knee injuries can be prevented through athletic development.

scholarly journals Passive Stiffness and Maximal and Explosive Strength Responses After an Acute Bout of Constant-Tension Stretching

2019 ◽  
Vol 54 (5) ◽  
pp. 519-526 ◽  
Author(s):  
Ty B. Palmer ◽  
Ryan M. Thiele
Keyword(s):  
Time Course ◽  
Outcome Measurement ◽  
Peak Torque ◽  
Passive Stiffness ◽  
Explosive Strength ◽  
Rate Of Torque Development ◽  
Short Bout ◽  
Constant Tension ◽  
Before And After ◽  
Torque Development

Context Constant-tension (CT) stretching has been used to reduce hamstrings passive stiffness; however, the time course of hamstrings stiffness responses during a short bout of this type of stretching and the effects on maximal and explosive strength remain unclear. Objective To examine the time course of hamstrings passive-stiffness responses during a short, practical bout of manual straight-legged–raise (SLR) CT passive stretches and their effects on maximal and explosive strength in healthy young women. Design Descriptive laboratory study. Setting Research laboratory. Patients or Other Participants Eleven healthy women (age = 24 ± 4 years, height = 167 ± 4 cm, mass = 65 ± 8 kg) participated. Intervention(s) Participants underwent four 15-second SLR CT passive stretches of the hamstrings. Main Outcome Measurement(s) Hamstrings passive stiffness was calculated from the slopes of the initial (phase 1) and final (phase 2) portions of the angle-torque curves generated before and after the stretching intervention and at the beginning of each 15-second stretch. Hamstrings peak torque and rate of torque development were derived from maximal voluntary isometric contractions performed before and after the stretching intervention. Results The slope coefficients (collapsed across phase) for the third and fourth stretches and the poststretching assessment were lower than the prestretching assessment (P range = .004–.04), but they were not different from each other (P &gt; .99). In addition, no differences in peak torque (t10 = −0.375, P = .72) or rate of torque development (t10 = −0.423, P = .68) were observed between prestretching and poststretching. Conclusions A short bout of SLR CT passive stretching may effectively reduce hamstrings stiffness without negatively influencing maximal and explosive strength.

scholarly journals The Relationship of Knee-Extensor Strength and Rate of Torque Development to Sit-to-Stand Performance in Older Adults

2013 ◽  
Vol 65 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Katie Crockett ◽  
Kimberly Ardell ◽  
Marlyn Hermanson ◽  
Andrea Penner ◽  
Joel Lanovaz ◽  
...  
Keyword(s):  
Older Adults ◽  
Knee Extensor ◽  
Sit To Stand ◽  
Rate Of Torque Development ◽  
Knee Extensor Strength ◽  
Relationship Of ◽  
The Relationship ◽  
Torque Development

Influence of gender on post-tetanic potentiation in human dorsiflexors

1998 ◽  
Vol 76 (7-8) ◽  
pp. 772-779 ◽  
Author(s):  
Deborah D O'Leary ◽  
Karen Hope ◽  
Digby G Sale
Keyword(s):  
Gender Difference ◽  
Young Women ◽  
Rise Time ◽  
Peak Torque ◽  
Similar Amount ◽  
Muscle Twitch ◽  
Rate Of Torque Development ◽  
Before And After ◽  
Post Tetanic Potentiation ◽  
Torque Development

Twitch contractions of the ankle dorsiflexors were evoked before and after 7 s of tetanic stimulation at 100 Hz in young women and men. Torque decreased more in men (18%) than in women (12%) during the tetanus. There was no gender difference in twitch peak torque potentiation over the 5-min post-tetanus. Potentiation was 42% (women) and 45% (men) at 5 s post-tetanus, and still present at 5 min (women 24%, men 25%). The immediate (5 s) shortening of twitch rise time was similar in women (14%) and men (13%), but during the 5-min men's rise time came to exceed whereas women's only approached pretetanus values (e.g., +9% vs. -1% at 5 min). The immediate decrease in half-relaxation time was also similar in women (24%) and men (22%); however, women's but not men's values remained less than pretetanus values for most of the 5-min period. Twitch rate of torque development increased similarly (75%) in women and men at 5 s, with no gender difference over 5 min. In contrast, rate of torque relaxation increased significantly only in men. Rate of torque development normalized to peak torque was similar in women and men pretetanus and increased similarly 5 s post-tetanus, but women had greater values through most of the 5-min post-tetanus. Normalized rate of torque relaxation was similar in women and men and not affected by tetanus. In the dorsiflexor muscles, young women and men show a similar amount and pattern of twitch force potentiation, but there are gender differences in time-related twitch contractile properties in the first 5 min after tetanus.Key words: contraction, muscle, twitch.

Effects of Concentric and Eccentric Strength Training on Fatigue Induced by Concentric and Eccentric Exercises

2019 ◽  
Vol 14 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Eduardo Lusa Cadore ◽  
Miriam González-Izal ◽  
Rafael Grazioli ◽  
Igor Setuain ◽  
Ronei Silveira Pinto ◽  
...  
Keyword(s):  
Maximal Voluntary Contraction ◽  
Isometric Force ◽  
Vastus Lateralis ◽  
Voluntary Contraction ◽  
Eccentric Training ◽  
Echo Intensity ◽  
Rate Of Torque Development ◽  
Before And After ◽  
Torque Development ◽  
Similar Force

Purpose: To compare the concentric and eccentric training effects on fatigue induced by eccentric and concentric protocols. Methods: A total of 22 men and women (22 [3.6] y) were assigned to concentric (GCON, n = 11) or eccentric training (GECC, n = 11). The concentric (CON) and eccentric (ECC) protocols were composed of 4 sets of 20 knee-extension/flexion repetitions. Force losses were analyzed by comparing 10 repetitions’ mean torques during the protocols and by verifying the maximal voluntary contraction and rate of torque development before and after the protocols. Muscle damage was assessed using echo intensity of the vastus lateralis 48 h after the protocols. Training consisted of 6 wk of isokinetic exercise at 60°/s (concentric or eccentric) twice weekly. Results: Before training, both protocols resulted in dynamic and isometric force losses in GCON and GECC (P < .01), but the magnitude was greater after the CON protocol than after the ECC protocol (P < .001). After training, both GCON and GECC showed similar force decreases during the CON and ECC protocols (P < .01), and these changes were not different from the pretraining decreases. Regarding maximal voluntary contraction after training, GECC showed lower force decreases than GCON after ECC exercise (−13.7% vs −22.3%, respectively, P < .05), whereas GCON showed lower maximal voluntary contraction decreases after CON exercise compared with pretraining (−29.2%, P < .05). Losses in rate of torque development were similar after the protocols before and after the training regimens. No changes in echo intensity were observed after the protocols before and after training. Conclusion: Both interventions resulted in similar force decreases during fatigue protocols compared with those associated with pretraining.

Influence of vibration resistance training on knee extensor and plantar flexor size, strength, and contractile speed characteristics after 60 days of bed rest

2009 ◽  
Vol 107 (6) ◽  
pp. 1789-1798 ◽  
Author(s):  
Edwin R. Mulder ◽  
Astrid M. Horstman ◽  
Dick F. Stegeman ◽  
Arnold de Haan ◽  
Daniel L. Belavý ◽  
...  
Keyword(s):  
Resistance Training ◽  
Knee Extensor ◽  
Bed Rest ◽  
Voluntary Contraction ◽  
Triceps Surae ◽  
Neural Activation ◽  
Cross Sectional ◽  
Rate Of Torque Development ◽  
Exercise Regimen ◽  
Torque Development

Spaceflight and bed rest (BR) result in loss of muscle mass and strength. This study evaluated the effectiveness of resistance training and vibration-augmented resistance training to preserve thigh (quadriceps femoris) and calf (triceps surae) muscle cross-sectional area (CSA), isometric maximal voluntary contraction (MVC), isometric contractile speed, and neural activation (electromyogram) during 60 days of BR. Male subjects participating in the second Berlin Bed Rest Study underwent BR only [control (CTR), n = 9], BR with resistance training (RE; n = 7), or BR with vibration-augmented resistance training (RVE; n = 7). Training was performed three times per week. Thigh CSA and MVC torque decreased by 13.5 and 21.3%, respectively, for CTR (both P < 0.001), but were preserved for RE and RVE. Calf CSA declined for all groups, but more so ( P < 0.001) for CTR (23.8%) than for RE (10.7%) and RVE (11.0%). Loss in calf MVC torque was greater ( P < 0.05) for CTR (24.9%) than for RVE (12.3%), but not different from RE (14.8%). Neural activation at MVC remained unchanged in all groups. For indexes related to rate of torque development, countermeasure subjects were pooled into one resistance training group (RT, n = 14). Thigh maximal rate of torque development (MRTD) and contractile impulse remained unaltered for CTR, but MRTD decreased 16% for RT. Calf MRTD remained unaltered for both groups, whereas contractile impulse increased across groups (28.8%), despite suppression in peak electromyogram (12.1%). In conclusion, vibration exposure did not enhance the efficacy of resistance training to preserve thigh and calf neuromuscular function during BR, although sample size issues may have played a role. The exercise regimen maintained thigh size and MVC strength, but promoted a loss in contractile speed. Whereas contractile speed improved for the calf, the exercise regimen only partially preserved calf size and MVC strength. Modification of the exercise regimen seems warranted.

Sign in / Sign up

Export Citation Format

Share Document