Editorial: Eccentric Training for Patients Recovering from COVID-19

AbstractDuchene muscular dystrophy (DMD) is caused by the absence of the protein dystrophin, which leads to muscle weakness, progressive degeneration, and eventually death due to respiratory failure. Low-intensity eccentric training (LIET) has been used as a rehabilitation method in skeletal muscles after disuse. Recently, LIET has also been used for rehabilitating dystrophic muscles, but its effects are still unclear. The purpose of this study was to investigate the effects of 21 days of LIET in dystrophic soleus muscle. Thirty-six male mdx mice were randomized into six groups (n = 6/each): mdx sedentary group; mdx training group-3 days; mdx training group-21 days; wild-type sedentary group; wild-type training group-3 days and wild-type training group-21 days. After the training sessions, animals were euthanized, and fragments of soleus muscles were removed for immunofluorescence and histological analyses, and measurements of active force and Ca2+ sensitivity of the contractile apparatus. Muscles of the mdx training group-21 days showed an improvement in morphological characteristics and an increase of active force when compared to the sedentary mdx group. The results show that LIET can improve the functionality of dystrophic soleus muscle in mice.

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Chronic Achilles Tendinopathy

The American Journal of Sports Medicine ◽

10.1177/0363546507303558 ◽

2007 ◽

Vol 35 (10) ◽

pp. 1659-1667 ◽

Cited By ~ 65

Author(s):

Wolf Petersen ◽

Robert Welp ◽

Dieter Rosenbaum

Keyword(s):

Synergistic Effect ◽

Short Form ◽

Achilles Tendinopathy ◽

Eccentric Training ◽

Treatment Groups ◽

Alternative Treatment Option ◽

Sf 36 ◽

Significant Difference ◽

Chronic Achilles Tendinopathy

Background Previous studies have shown that eccentric training has a positive effect on chronic Achilles tendinopathy. A new strategy for the treatment of chronic Achilles tendinopathy is the AirHeel brace. Hypothesis AirHeel brace treatment improves the clinical outcome of patients with chronic Achilles tendinopathy. The combination of the AirHeel brace and an eccentric training program has a synergistic effect. Study Design Randomized controlled clinical trial; Level of evidence, 1. Methods One hundred patients were randomly assigned to 1 of 3 treatment groups: (1) eccentric training, (2) AirHeel brace, and (3) combination of eccentric training and AirHeel brace. Patients were evaluated at 6, 12, and 54 weeks after the beginning of the treatment protocol with ultrasonography, visual analog scale (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) ankle score, and Short Form-36 (SF-36). Results The VAS score for pain, AOFAS score, and SF-36 improved significantly in all 3 groups at all 3 follow-up examinations. At the 3 time points (6 weeks, 12 weeks, and 54 weeks) of follow-up, there was no significant difference between all 3 treatment groups. In all 3 groups, there was no significant difference in tendon thickness after treatment. Conclusions The AirHeel brace is as effective as eccentric training in the treatment of chronic Achilles tendinopathy. There is no synergistic effect when both treatment strategies are combined. Clinical Relevance The AirHeel brace is an alternative treatment option for chronic Achilles tendinopathy.

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Changes in H reflex and neuromechanical properties of the trapezius muscle after 5 weeks of eccentric training: a randomized controlled trial

Journal of Applied Physiology ◽

10.1152/japplphysiol.00164.2014 ◽

2014 ◽

Vol 116 (12) ◽

pp. 1623-1631 ◽

Cited By ~ 15

Author(s):

Steffen Vangsgaard ◽

Janet L. Taylor ◽

Ernst A. Hansen ◽

Pascal Madeleine

Keyword(s):

Electrical Stimulation ◽

Strength Training ◽

Reference Group ◽

Controlled Trial ◽

Trapezius Muscle ◽

Training Group ◽

H Reflex ◽

Eccentric Training ◽

Voluntary Activity ◽

Stimulation Of

Trapezius muscle Hoffman (H) reflexes were obtained to investigate the neural adaptations induced by a 5-wk strength training regimen, based solely on eccentric contractions of the shoulder muscles. Twenty-nine healthy subjects were randomized into an eccentric training group ( n = 15) and a reference group ( n = 14). The eccentric training program consisted of nine training sessions of eccentric exercise performed over a 5-wk period. H-reflex recruitment curves, the maximal M wave (Mmax), maximal voluntary contraction (MVC) force, rate of force development (RFD), and electromyographic (EMG) voluntary activity were recorded before and after training. H reflexes were recorded from the middle part of the trapezius muscle by electrical stimulation of the C3/4 cervical nerves; Mmax was measured by electrical stimulation of the accessory nerve. Eccentric strength training resulted in significant increases in the maximal trapezius muscle H reflex (Hmax) (21.4% [5.5–37.3]; P = 0.01), MVC force (26.4% [15.0–37.7]; P < 0.01), and RFD (24.6% [3.2–46.0]; P = 0.025), while no significant changes were observed in the reference group. Mmax remained unchanged in both groups. A significant positive correlation was found between the change in MVC force and the change in EMG voluntary activity in the training group ( r = 0.57; P = 0.03). These results indicate that the net excitability of the trapezius muscle H-reflex pathway increased after 5 wk of eccentric training. This is the first study to investigate and document changes in the trapezius muscle H reflex following eccentric strength training.

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Modifiability of the history dependence of force through chronic eccentric and concentric biased resistance training

Journal of Applied Physiology ◽

10.1152/japplphysiol.00928.2018 ◽

2019 ◽

Vol 126 (3) ◽

pp. 647-657 ◽

Cited By ~ 11

Author(s):

Jackey Chen ◽

Geoffrey A. Power

Keyword(s):

Steady State ◽

Resistance Training ◽

Isometric Force ◽

Eccentric Training ◽

Force Enhancement ◽

History Dependence ◽

Force Depression ◽

Residual Force ◽

Residual Force Enhancement ◽

Concentric Training

The increase and decrease in steady-state isometric force following active muscle lengthening and shortening are referred to as residual force enhancement (RFE) and force depression (FD), respectively. The RFE and FD states are associated with decreased (activation reduction; AR) and increased (activation increase; AI) neuromuscular activity, respectively. Although the mechanisms have been discussed over the last 60 years, no studies have systematically investigated the modifiability of RFE and FD with training. The purpose of the present study was to determine whether RFE and FD could be modulated through eccentric and concentric biased resistance training. Fifteen healthy young adult men (age: 24 ± 2 yr, weight: 77 ± 8 kg, height: 178 ± 5 cm) underwent 4 wk of isokinetic dorsiflexion training, in which one leg was trained eccentrically (−25°/s) and the other concentrically (+25°/s) over a 50° ankle excursion. Maximal and submaximal (40% maximum voluntary contraction) steady-state isometric torque and EMG values following active lengthening and shortening were compared to purely isometric values at the same joint angles and torque levels. Residual torque enhancement (rTE) decreased by ~36% after eccentric training ( P < 0.05) and increased by ~89% after concentric training ( P < 0.05), whereas residual torque depression (rTD), AR, AI, and optimal angles for torque production were not significantly altered by resistance training ( P ≥ 0.05). It appears that rTE, but not rTD, for the human ankle dorsiflexors is differentially modifiable through contraction type-dependent resistance training. NEW & NOTEWORTHY The history dependence of force production is a property of muscle unexplained by current cross bridge and sliding filament theories. Whether a muscle is actively lengthened (residual force enhancement; RFE) or shortened (force depression) to a given length, the isometric force should be equal to a purely isometric contraction—but it is not! In this study we show that eccentric training decreased RFE, whereas concentric training increased RFE and converted all nonresponders (i.e., not exhibiting RFE) into responders.

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Adaptive Response in Human Skeletal Muscle Subjected to Prolonged Eccentric Training

International Journal of Sports Medicine ◽

10.1055/s-2008-1026031 ◽

1983 ◽

Vol 04 (03) ◽

pp. 177-183 ◽

Cited By ~ 108

Author(s):

J. Fridén ◽

J. Seger ◽

M. Sjöström ◽

B. Ekblom

Keyword(s):

Skeletal Muscle ◽

Adaptive Response ◽

Human Skeletal Muscle ◽

Eccentric Training

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The effects of eccentric training on hamstring muscle architecture

Kinesiology ◽

10.26582/k.53.1.17 ◽

2021 ◽

Vol 53 (1) ◽

pp. 141-153

Author(s):

Murat Emirzeoğlu ◽

Tüzün Fırat ◽

Özlem Ülger

Keyword(s):

Training Session ◽

Muscle Thickness ◽

Muscle Architecture ◽

Eccentric Training ◽

Hamstring Muscle ◽

Cross Sectional ◽

Functional Changes ◽

Hamstring Injuries ◽

Architectural Features ◽

Hand Muscle

The architectural features of the hamstring muscle group are important to prevent injury or to reduce the risk of re-injury. Besides, eccentric training is often used in the rehabilitation of hamstring injuries. The aim of this systematic review was to examine the changes created by eccentric training on hamstring muscle architecture and to determine the minimal values of training duration and intensity for requiring functional changes. The research was conducted on the PubMed, Scopus, Web of Science, COCHRANE, CINAHL, and Pedro databases. Full-text studies examining the effect of eccentric training on at least one parameter of the hamstring muscle architecture were included in the review. Studies on cadavers and animals and studies involving different types of training combined with eccentric training were excluded. Twelve of the 7954 studies met the set criteria. According to the results, eccentric training undoubtedly increases fiber length. However, the pennation angle tends to decrease. On the other hand, muscle thickness and cross-sectional area tends to increase depending on the eccentric training. Although the frequency, number of sets and number of repetitions in sets were similar in the examined studies, muscle architecture changes were different. We think that eccentric training duration and the number of repetitions in total or per training session seem to have an impact on muscle architecture. In order to determine the minimal eccentric training program that can create these changes, quality research is needed to examine the duration, intensity and methods of eccentric training.

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