Rate of Torque Development and Voluntary Quadriceps Activation in Patients With Knee Osteoarthritis: A Quantitative Analysis Before and After a Single Session of Manual Physical Therapy

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 > .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.

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Deficits in rate of torque development are accompanied by activation failure in patients with knee osteoarthritis

Journal of Electromyography and Kinesiology ◽

10.1016/j.jelekin.2018.11.010 ◽

2019 ◽

Vol 44 ◽

pp. 94-100 ◽

Cited By ~ 1

Author(s):

A. Ventura ◽

B. Muendle ◽

B. Friesenbichler ◽

N.C. Casartelli ◽

I. Kramers ◽

...

Keyword(s):

Knee Osteoarthritis ◽

Rate Of Torque Development ◽

Torque Development

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Influence of gender on post-tetanic potentiation in human dorsiflexors

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y98-108 ◽

1998 ◽

Vol 76 (7-8) ◽

pp. 772-779 ◽

Cited By ~ 13

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.

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

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2018-0254 ◽

2019 ◽

Vol 14 (1) ◽

pp. 91-98 ◽

Cited By ~ 3

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.

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The Acute Effects of Fast-Paced Walking on Isometric Peak Torque and Rate of Torque Development in Regularly Exercising and Inactive Older Women

Journal of Aging and Physical Activity ◽

10.1123/japa.2021-0123 ◽

2021 ◽

pp. 1-7

Author(s):

Ty B. Palmer ◽

Jarrod Blinch ◽

Ahalee C. Farrow ◽

Chinonye C. Agu-Udemba ◽

Ethan A. Mitchell

Keyword(s):

Physical Activity ◽

Older Women ◽

Peak Torque ◽

Knee Extension ◽

Acute Effects ◽

Rate Of Torque Development ◽

Isometric Knee Extension ◽

Before And After ◽

Inactive Group ◽

Torque Development

This study aimed to examine the acute effects of fast-paced walking on isometric peak torque and rate of torque development (RTD) in regular exercising and inactive older women. Ten regular exercising (67 ± 4 years) and 10 inactive (68 ± 4 years) older women performed three isometric knee extension contractions before and after a control condition (quiet resting) and an experimental condition of fast-paced walking for 6 min. Peak torque and early (RTD100), late (RTD200), and maximum (peak RTD) RTD measurements were obtained from each contraction. Results showed no significant changes in peak torque, peak RTD, or RTD200 after walking for either group (p > .050). A significant decrease in RTD100 was observed after walking for the inactive group (p = .005) but not for the regular exercisers (p = .909). These findings highlight the importance of physical activity and suggest that a task as simple as walking may impair the rapid strength capacities of inactive older women.

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Post Activation Potentiation of the Plantarflexors: Implications of Knee Angle Variations

Journal of Human Kinetics ◽

10.1515/hukin-2017-0044 ◽

2017 ◽

Vol 57 (1) ◽

pp. 29-38 ◽

Cited By ~ 3

Author(s):

Paulo Gago ◽

Anton Arndt ◽

Maria M. Ekblom

Keyword(s):

Peak Torque ◽

Medial Gastrocnemius ◽

Knee Angle ◽

Rate Of Torque Development ◽

Male Power ◽

Extended Position ◽

Significant Difference ◽

Before And After ◽

The Mean ◽

Torque Development

AbstractFlexing the knee to isolate the single joint soleus from the biarticular gastrocnemius is a strategy for investigating individual plantarflexor’s post activation potentiation (PAP). We investigated the implications of testing plantarflexor PAP at different knee angles and provided indirect quantification of the contribution of gastrocnemius potentiation to the overall plantarflexor enhancements post conditioning. Plantarflexor supramaximal twitches were measured in ten male power athletes before and after a maximal isometric plantarflexion (MVIC) at both flexed and extended knee angles. Mean torque and soleus (SOLRMS) and medial gastrocnemius (MGRMS) activity were measured during the MVIC. The mean torque and MGRMS of the MVIC were lower (by 33.9 and 42.4%, respectively) in the flexed compared to the extended position, with no significant difference in SOLRMS. After the MVIC, twitch peak torque (PT) and the rate of torque development (RTR) potentiated significantly more (by 17.4 and 14.7% respectively) in the extended as compared to the flexed knee position, but only immediately (5 s) after the MVIC. No significant differences were found in the twitch rate of torque development (RTD) potentiation between positions. It was concluded that knee joint configuration should be taken into consideration when comparing studies of plantarflexor PAP. Furthermore, results reflect a rather brief contribution of the gastrocnemius potentiation to the overall plantarflexor twitch enhancements.

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Neuromuscular and Torque Kinetic Changes After 10 Months of Explosive Sport Training in Prepubertal Gymnasts

Pediatric Exercise Science ◽

10.1123/pes.2018-0034 ◽

2019 ◽

Vol 31 (1) ◽

pp. 77-84 ◽

Cited By ~ 1

Author(s):

Andrzej Kochanowicz ◽

Bartłomiej Niespodziński ◽

Jan Mieszkowski ◽

Stanisław Sawczyn ◽

Paweł Cięszczyk ◽

...

Keyword(s):

Elbow Flexion ◽

Peak Torque ◽

Sport Training ◽

Explosive Strength ◽

Rate Of Torque Development ◽

Before And After ◽

Prepubertal Boys ◽

Baseline Values ◽

Covariation Analysis ◽

Torque Development

Purpose: To determine neuromuscular and torque kinetic changes after 10 months of explosive sport training in the elbow of prepubertal gymnasts compared with untrained age-matched controls. Methods: In 15 young gymnasts (9.02 [0.41] y) and 15 age-matched untrained males (8.76 [0.51] y), the rate of torque development (RTD) using the Biodex System 4 and the coactivation index were evaluated using electromyography. Explosive strength variables were normalized to the peak torque. Measures were determined twice: before and after a 10-month period of gymnastic training. Covariation analysis was used to account for differences in baseline values between gymnasts and controls. Results: After 10 months of training, gymnasts demonstrated a significantly (P < .05) greater increase in normalized peak RTD values in elbow flexion compared with controls (7.76% vs 0.65%). Covariation analysis also revealed a significantly (P < .05) greater reduction in the coactivation index of elbow extension in the gymnasts (−7.81% [5.44%] points) compared with controls (−1.23% [6.32%] points). Conclusions: Compared with physical development alone, 10 months of explosive-strength training of young gymnasts is sufficient to increase torque-normalized RTD in the elbow joint of prepubertal boys. The RTD changes the authors observed in antagonistic elbow functions vary among gymnasts due to the specific demands of gymnastic training.

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