The Inhibitory Tendon-Evoked Reflex Is Increased in the Torque-Enhanced State Following Active Lengthening Compared to a Purely Isometric Contraction

Contento, Vincenzo S.; Dalton, Brian H.; Power, Geoffrey A.

doi:10.3390/brainsci10010013

Cited by 13 publications

(12 citation statements)

References 35 publications

(88 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During submaximal dorsiflexion contractions, Sypkes et al (2018) found unchanged TA MEPs, but reduced TA CMEPs, following active muscle stretch compared with fixed-end reference contractions. This is in line with the idea of reduced motor unit recruitment (Altenburg et al 2008) and might be caused by tension-related afferent feedback as assessed by tendon-evoked inhibitory reflexes (Contento et al 2019). Contrary to these findings under submaximal contraction intensities, Hahn et al (2012) found larger MEPs, but unchanged CMEPs, following stretch of the plantar flexors during maximal voluntary contractions.…”

Section: Introductionsupporting

confidence: 88%

“…The unchanged MEP amplitudes and SP durations that we found in the presence of rFE compared with the reference contractions is in line with the findings of Sypkes et al (2018) and indicate that the overall corticospinal excitability was unaffected. However, unchanged MEPs do not exclude potential spinal modulations and the smaller CMEP amplitudes in the presence of rFE observed by Sypkes et al (2018) could be interpreted as reduced spinal motoneuron excitability, which might be due to tension-related afferent feedback from Golgi tendon organs (Contento et al 2019). Accordingly, we assume that the unchanged MEP amplitudes in our study reflect an increased cortical excitability, which did not contribute to the increased torque production following active muscle stretch.…”

Section: Discussionmentioning

confidence: 99%

“…Contrary to our predictions, a contribution of corticospinal drive to the increased torque production following active muscle stretch could not be confirmed. However, it remains unknown whether and how the spinal modulations observed by others (Altenburg et al 2008, Sypkes et al 2018, Contento et al 2019) affect torque production in the presence of rFE.…”

Section: Discussionmentioning

confidence: 99%

“…However, whether neural inhibition occurs during and following active stretch under voluntary activation remains controversial (Hahn, 2018). The potentially unique control of stretch-hold contractions and the observation of AR following active stretch has motivated a number of studies to investigate the neural control and/or neural modulations that occur during the isometric steady state following active muscle stretch (Altenburg et al, 2008; Contento et al, 2019; Hahn et al, 2012; Sypkes et al, 2018). For example, Altenburg et al (2008) examined single motor unit behaviour of the vastus lateralis muscle during AR after active muscle stretch.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Frischholz

Raiteri

Hahn

2020

Preprint

View full text Add to dashboard Cite

23Following active muscle stretch, a muscle's force capacity is increased, which is known as 24 residual force enhancement (rFE). As earlier studies found modulations of cortical excitability 25 in the presence of rFE, this study aimed to test whether corticospinal drive contributes to rFE. 26 Fourteen participants performed submaximal plantar flexion stretch-hold and fixed-end 27 contractions at 30% of their maximal voluntary soleus muscle activity in a dynamometer. 28 During the steady state of the contractions, participants either received subthreshold or 29 suprathreshold transcranial magnetic stimulation (TMS) of their motor cortex while triceps 30 surae muscle responses to stimulation were obtained by electromyography (EMG) and net 31 plantar flexion torque was recorded. B-mode ultrasound imaging was used to confirm muscle 32 stretch during stretch-hold contractions in a subset of participants. Following stretch of the 33 plantar flexors, an average rFE of 7% and 11% was observed for contractions with 34 subthreshold and suprathreshold TMS, respectively. 42-46 milliseconds following 35 subthreshold TMS, triceps surae muscle activity was suppressed by 19-24%, but no difference 36 in suppression was found between contraction conditions. Similarly, the reduction in plantar 37 flexion torque following subthreshold TMS was not different between contraction conditions. 38Motor evoked potentials, silent periods and superimposed twitches following suprathreshold 39 stimulations were also not different between contraction conditions. As stimulations of the 40 motor cortex by TMS did not result in any differences between stretch-hold and fixed-end 41 contractions, we conclude that corticospinal drive does not contribute to the increased torque 42 production in the presence of rFE following active muscle stretch. 43 44 New & Noteworthy 45 This study tested whether corticospinal drive contributes to the increased torque capacity in 46 the presence of rFE. Through subthreshold and suprathreshold TMS of the motor cortex, 47 51 52 Keywords: eccentric contraction, active muscle stretch, neural control, cortical excitability, 53 torque enhancement 54 55It is well known that stretch of an active muscle results in increased force production during 56 the isometric steady state following stretch compared with the steady-state force produced at 57 the same muscle length and activation level during a fixed-end contraction. This is referred to 58 as residual force enhancement (rFE), which was initially investigated in situ (Abbott and 59 Aubert, 1952) and in isolated muscle fibres (Edman et al., 1982). Edman et al. (1982) 60 suggested that rFE after active muscle stretch results from non-uniformities in sarcomere 61 lengths. Since then, a variety of studies have investigated the development of rFE and 62 suggested additional potential underlying mechanisms. These suggestions include stretch-63 induced increases in the number of attached cross-bridges, an increase in the average cross-64 bridge force and/or the attachment...

show abstract

Section: Introductionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Frischholz

Raiteri

Hahn

2020

Preprint

View full text Add to dashboard Cite

show abstract

“…While a reduction in agonist activation is almost certain, it appears to be related, in part, to spinal excitability (Sypkes et al 2018). Contento et al (2019) reported an increased tendonevoked inhibitory reflex during the rFE state compared to strictly isometric contractions. These results likely indicate inhibitory feedback onto the agonist motoneuron pool that is arising from a tension-dependent source within the tendon, most likely the golgi tendon organ, and subsequently reducing spinal excitability (Sypkes et al 2018).…”

mentioning

confidence: 99%