scholarly journals Corticospinal excitability remains unchanged in the presence of residual force enhancement and does not contribute to increased torque production

PeerJ ◽  
2022 ◽  
Vol 10 ◽  
pp. e12729
Author(s):  
Jasmin Frischholz ◽  
Brent J. Raiteri ◽  
Andrew G. Cresswell ◽  
Daniel Hahn
Keyword(s):  
Motor Cortex ◽  
Muscle Activity ◽  
Plantar Flexion ◽  
Corticospinal Excitability ◽  
Triceps Surae ◽  
Force Enhancement ◽  
Triceps Surae Muscle ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Fixed End

Background Following stretch of an active muscle, muscle force is enhanced, which is known as residual force enhancement (rFE). As earlier studies found apparent corticospinal excitability modulations in the presence of rFE, this study aimed to test whether corticospinal excitability modulations contribute to rFE. Methods Fourteen participants performed submaximal plantar flexion stretch-hold and fixed-end contractions at 30% of their maximal voluntary soleus muscle activity in a dynamometer. During the steady state of the contractions, participants either received subthreshold or suprathreshold transcranial magnetic stimulation (TMS) of their motor cortex, while triceps surae muscle responses to stimulation were obtained via electromyography (EMG), and net ankle joint torque was recorded. B-mode ultrasound imaging was used to confirm muscle fascicle stretch during stretch-hold contractions in a subset of participants. Results Following stretch of the plantar flexors, an average rFE of 7% and 11% was observed for contractions with subthreshold and suprathreshold TMS, respectively. 41–46 ms following subthreshold TMS, triceps surae muscle activity was suppressed by 19–25%, but suppression was not significantly different between stretch-hold and fixed-end contractions. Similarly, the reduction in plantar flexion torque following subthreshold TMS was not significantly different between contraction conditions. Motor evoked potentials, silent periods and superimposed twitches following suprathreshold TMS were also not significantly different between contraction conditions. Discussion As TMS of the motor cortex did not result in any differences between stretch-hold and fixed-end contractions, we conclude that rFE is not linked to changes in corticospinal excitability.

scholarly journals Corticospinal drive does not contribute to increased torque production in the presence of residual force enhancement

2020 ◽  
Author(s):  
Jasmin Frischholz ◽  
Brent J. Raiteri ◽  
Daniel Hahn
Keyword(s):  
Motor Cortex ◽  
Muscle Activity ◽  
Plantar Flexion ◽  
Triceps Surae ◽  
Muscle Stretch ◽  
Triceps Surae Muscle ◽  
Torque Capacity ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Fixed End

AbstractFollowing active muscle stretch, a muscle’s force capacity is increased, which is known as residual force enhancement (rFE). As earlier studies found modulations of cortical excitability in the presence of rFE, this study aimed to test whether corticospinal drive contributes to rFE. Fourteen participants performed submaximal plantar flexion stretch-hold and fixed-end contractions at 30% of their maximal voluntary soleus muscle activity in a dynamometer. During the steady state of the contractions, participants either received subthreshold or suprathreshold transcranial magnetic stimulation (TMS) of their motor cortex while triceps surae muscle responses to stimulation were obtained by electromyography (EMG) and net plantar flexion torque was recorded. B-mode ultrasound imaging was used to confirm muscle stretch during stretch-hold contractions in a subset of participants. Following stretch of the plantar flexors, an average rFE of 7% and 11% was observed for contractions with subthreshold and suprathreshold TMS, respectively. 41-46 milliseconds following subthreshold TMS, triceps surae muscle activity was suppressed by 19-25%, but no difference in suppression was found between contraction conditions. Similarly, the reduction in plantar flexion torque following subthreshold TMS was not different between contraction conditions. Motor evoked potentials, silent periods and superimposed twitches following suprathreshold stimulations were also not different between contraction conditions. As stimulations of the motor cortex by TMS did not result in any differences between stretch-hold and fixed-end contractions, we conclude that corticospinal drive does not contribute to the increased torque production in the presence of rFE following active muscle stretch.New & NoteworthyThis study tested whether corticospinal drive contributes to the increased torque capacity in the presence of rFE. Through subthreshold and suprathreshold TMS of the motor cortex, triceps surae muscle activity was respectively supressed or increased in the presence of rFE and during a reference contraction without rFE. As similar responses were observed between contraction contractions, we conclude that corticospinal drive likely does not contribute to the increased torque capacity in the presence of rFE.

scholarly journals Residual force enhancement after lengthening is present during submaximal plantar flexion and dorsiflexion actions in humans

2007 ◽  
Vol 102 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Gavin J. Pinniger ◽  
Andrew G. Cresswell
Keyword(s):  
Plantar Flexion ◽  
Joint Torque ◽  
Voluntary Activation ◽  
Force Enhancement ◽  
Leg Muscles ◽  
Isometric Torque ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Underlying Mechanisms ◽  
Activation Conditions

Stretch of an activated muscle causes a transient increase in force during the stretch and a sustained, residual force enhancement (RFE) after the stretch. The purpose of this study was to determine whether RFE is present in human muscles under physiologically relevant conditions (i.e., when stretches were applied within the working range of large postural leg muscles and under submaximal voluntary activation). Submaximal voluntary plantar flexion (PFv) and dorsiflexion (DFv) activation was maintained by providing direct visual feedback of the EMG from soleus or tibialis anterior, respectively. RFE was also examined during electrical stimulation of the plantar flexion muscles (PFs). Constant-velocity stretches (15°/s) were applied through a range of motion of 15° using a custom-built ankle torque motor. The muscles remained active throughout the stretch and for at least 10 s after the stretch. In all three activation conditions, the stable joint torque measured 9–10 s after the stretch was greater than the isometric joint torque at the final joint angle. When expressed as a percentage of the isometric torque, RFE values were 7, 13, and 12% for PFv, PFs, DFv, respectively. These findings indicate that RFE is a characteristic of human skeletal muscle and can be observed during submaximal (25%) voluntary activation when stretches are applied on the ascending limb of the force-length curve. Although the underlying mechanisms are unclear, it appears that sarcomere popping and passive force enhancement are insufficient to explain the presence of RFE in these experiments.

scholarly journals Residual force enhancement in human skeletal muscles: A systematic review and meta-analysis

2021 ◽  
Author(s):  
Daiani de Campos ◽  
Lucas B.R. Orssatto ◽  
Gabriel S. Trajano ◽  
Walter Herzog ◽  
Heiliane de Brito Fontana
Keyword(s):  
Systematic Review ◽  
Skeletal Muscles ◽  
Meta Analysis ◽  
Force Enhancement ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Human Skeletal Muscles

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

2019 ◽  
Vol 126 (3) ◽  
pp. 647-657 ◽  
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.

scholarly journals Residual force enhancement in skeletal muscle

2006 ◽  
Vol 574 (3) ◽  
pp. 635-642 ◽  
Author(s):  
W. Herzog ◽  
E. J. Lee ◽  
D. E. Rassier
Keyword(s):  
Skeletal Muscle ◽  
Force Enhancement ◽  
Residual Force ◽  
Residual Force Enhancement

scholarly journals Force enhancement after stretch of isolated myofibrils is increased by sarcomere length non-uniformities

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ricarda M. Haeger ◽  
Dilson E. Rassier
Keyword(s):  
Steady State ◽  
Sarcomere Length ◽  
Isometric Force ◽  
Force Production ◽  
Force Enhancement ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
State Force ◽  
Isometric Forces

AbstractWhen a muscle is stretched during a contraction, the resulting steady-state force is higher than the isometric force produced at a comparable sarcomere length. This phenomenon, also referred to as residual force enhancement, cannot be readily explained by the force-sarcomere length relation. One of the most accepted mechanisms for the residual force enhancement is the development of sarcomere length non-uniformities after an active stretch. The aim of this study was to directly investigate the effect of non-uniformities on the force-producing capabilities of isolated myofibrils after they are actively stretched. We evaluated the effect of depleting a single A-band on sarcomere length non-uniformity and residual force enhancement. We observed that sarcomere length non-uniformity was effectively increased following A-band depletion. Furthermore, isometric forces decreased, while the percent residual force enhancement increased compared to intact myofibrils (5% vs. 20%). We conclude that sarcomere length non-uniformities are partially responsible for the enhanced force production after stretch.

Peak triceps surae muscle activity is not specific to knee flexion angles during MVIC

2011 ◽  
Vol 21 (5) ◽  
pp. 819-826 ◽  
Author(s):  
Kim Hébert-Losier ◽  
Anthony G. Schneiders ◽  
José A. García ◽  
S. John Sullivan ◽  
Guy G. Simoneau
Keyword(s):  
Muscle Activity ◽  
Knee Flexion ◽  
Triceps Surae ◽  
Triceps Surae Muscle
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