Homosynaptic depression (HD) refers to the reduction in the magnitude of the monosynaptic spinal reflex resulting from prior activation of the circuit, often evoked with the H-reflex. Previous literature has reported HD of the soleus H-reflex is reduced post-stroke. However, it remains unclear if HD plays a role in functional impairments. The goal of this study was to characterize HD of the soleus H-reflex in individuals with post-stroke gait impairments and examine the relationship with functional measures of gait. Our results revealed that individuals after stroke experienced reduced depression at longer (8s) interstimulus intervals compared to age-matched neurologically intact individuals. However, we did not observe a difference in the change in HD across interstimulus intervals between groups, contrary to previous reports. This finding could not be explained by age of participants. In addition, we found a strong correlation between faster gait speed and reduced change in depression in individuals after stroke. While the underlying mechanisms linking HD with gait are unclear, this finding represents the first piece of evidence of the potential role of HD in function. Further research is needed to understand the parameters that guide HD and clarify how useful the mechanism is for improving the assessment and treatment of post-stroke impairments.
AkbasT.KimK.DoyleK.ManellaK.LeeR.SpicerP.KnikouM.SulzerJ. (2020). Rectus femoris hyperreflexia contributes to Stiff-Knee gait after stroke. Journal of NeuroEngineering and Rehabilitation, 17(1), 117. https://doi.org/10.1186/s12984-020-00724-z
2.
AymardC.KatzR.LafitteC.LoE.PénicaudA.Pradat-DiehlP.RaoulS. (2000). Presynaptic inhibition and homosynaptic depression: A comparison between lower and upper limbs in normal human subjects and patients with hemiplegia. Brain, 123(8), 1688–1702. https://doi.org/10.1093/brain/123.8.1688
3.
BohannonR. W.SmithM. B. (1987). Interrater reliability of a modified Ashworth scale of muscle spasticity. Physical Therapy, 67(2), 206–207. https://doi.org/10.1093/ptj/67.2.206
4.
ColardJ.JubeauM.CrouzierM.DuclayJ.CattagniT. (2024). Effect of muscle length on the modulation of H-reflex and inhibitory mechanisms of Ia afferent discharges during passive muscle lengthening. Journal of Neurophysiology, 132(3), 890–905. https://doi.org/10.1152/jn.00142.2024
5.
ColardJ.JubeauM.DuclayJ.CattagniT. (2023). Regulation of primary afferent depolarization and homosynaptic post-activation depression during passive and active lengthening, shortening and isometric conditions. European Journal of Applied Physiology, 123(6), 1257–1269. https://doi.org/10.1007/s00421-023-05147-x
6.
CroneC.NielsenJ. (1989). Methodological implications of the post activation depression of the soleus H-reflex in man. Experimental Brain Research, 78(1), 28–32. https://doi.org/10.1007/BF00230683
7.
CuadraC.WolfS. L.LyleM. A. (2023). Differential effect of heteronymous feedback from femoral nerve and quadriceps muscle stimulation onto soleus H-reflex. PLOS ONE, 18(8), e0290078. https://doi.org/10.1371/journal.pone.0290078
8.
CuadraC.WolfS. L.LyleM. A. (2025). Heteronymous feedback from quadriceps onto soleus in stroke survivors. Journal of NeuroEngineering and Rehabilitation, 22(1), 39. https://doi.org/10.1186/s12984-025-01572-5
CurtisD. R.LaceyG. (1998). Prolonged GABA(B) receptor-mediated synaptic inhibition in the cat spinal cord: An in vivo study. Experimental Brain Research, 121(3), 319–333. https://doi.org/10.1007/s002210050465
11.
DukkipatiS. S.WalkerS. J.TrevarrowM. P.BusboomM. T.KurzM. J. (2023). Spinal cord H-reflex post-activation depression is linked with hand motor control in adults with cerebral palsy. Clinical Neurophysiology, 148, 9–16. https://doi.org/10.1016/j.clinph.2023.01.004
12.
DyerJ.-O.MaupasE.MeloS. d. A.BourbonnaisD.FleuryJ.ForgetR. (2009). Transmission in heteronymous spinal pathways is modified after stroke and related to motor incoordination. PLOS ONE, 4(1), e4123. https://doi.org/10.1371/journal.pone.0004123
13.
EcclesJ. C.EcclesR. M.MagniF. (1961). Central inhibitory action attributable to presynaptic depolarization produced by muscle afferent volleys. The Journal of Physiology, 159(1), 147–166. https://doi.org/10.1113/jphysiol.1961.sp006798
14.
FloeterM. K.KohnA. F. (1997). H-reflexes of different sizes exhibit differential sensitivity to low frequency depression. Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, 105(6), 470–475. https://doi.org/10.1016/S0924-980X(97)00032-5
15.
HirstG. D.RedmanS. J.WongK. (1981). Post-tetanic potentiation and facilitation of synaptic potentials evoked in cat spinal motoneurones. The Journal of Physiology, 321, 97–109. https://doi.org/10.1113/jphysiol.1981.sp013973
16.
HultbornH.IllertM.NielsenJ.PaulA.BallegaardM.WieseH. (1996). On the mechanism of the post-activation depression of the H-reflex in human subjects. Experimental Brain Research, 108(3), 450–462. https://doi.org/10.1007/BF00227268
17.
KawaishiY.MatsumotoN.NishiwakiT.HiranoT. (2017). Postactivation depression of soleus H-reflex increase with recovery of lower extremities motor functions in patients with subacute stroke. Journal of Physical Therapy Science, 29(9), 1539–1542. https://doi.org/10.1589/jpts.29.1539
18.
KendallF.KendallM. E.GeiseP. P.McIntyreR. M.RomaniW. (2005). Muscles testing and function with posture and pain (Fifth). Lippincott Williams and Wilkins.
19.
KiserT. S.ReeseN. B.MareshT.HearnS.YatesC.SkinnerR.PaitT. G.Garcia-RillE. (2005). Use of a motorized bicycle exercise trainer to normalize frequency-dependent habituation of the H-reflex in spinal cord injury. The Journal of Spinal Cord Medicine, 28(3), 241–245. https://doi.org/10.1080/10790268.2005.11753818
20.
KunoM. (1964). Mechanism of facilitation and depression of the excitatory synaptic potential in spinal motoneurones. The Journal of Physiology, 175(1), 100–112. https://doi.org/10.1113/jphysiol.1964.sp007505
LamyJ.-C.WargonI.MazevetD.GhanimZ.Pradat-DiehlP.KatzR. (2009). Impaired efficacy of spinal presynaptic mechanisms in spastic stroke patients. Brain, 132(3), 734–748. https://doi.org/10.1093/brain/awn310
23.
MahmoudW.HultbornH.ZuluagaJ.ZrennerC.ZrennerB.ZiemannU.Ramos-MurguialdayA. (2023). Testing spasticity mechanisms in chronic stroke before and after intervention with contralesional motor cortex 1 Hz rTMS and physiotherapy. Journal of NeuroEngineering and Rehabilitation, 20, 150. https://doi.org/10.1186/s12984-023-01275-9
24.
MenouxD.JousseM.QuintaineV.TliliL.YelnikA. P. (2019). Decrease in post-stroke spasticity and shoulder pain prevalence over the last 15 years. Annals of Physical and Rehabilitation Medicine, 62(6), 403–408. https://doi.org/10.1016/j.rehab.2018.03.003
25.
MetzK.MatosI. C.HariK.BseisO.AfsharipourB.LinS.SinglaR.FenrichK. K.LiY.BennettD. J.GorassiniM. A. (2023). Post-activation depression from primary afferent depolarization (PAD) produces extensor H-reflex suppression following flexor afferent conditioning. The Journal of Physiology, 601(10), 1925–1956. https://doi.org/10.1113/JP283706
26.
MeunierS.KwonJ.RussmannH.RavindranS.MazzocchioR.CohenL. (2007). Spinal use-dependent plasticity of synaptic transmission in humans after a single cycling session. The Journal of Physiology, 579(Pt 2), 375–388. https://doi.org/10.1113/jphysiol.2006.122911
27.
MillerE. M.SlotaG. P.AgnewM. J.MadiganM. L. (2010). Females exhibit shorter paraspinal reflex latencies than males in response to sudden trunk flexion perturbations. Clinical Biomechanics, 25(6), 541–545. https://doi.org/10.1016/j.clinbiomech.2010.02.012
28.
ObataH.KimG.OgawaT.SekiguchiH.NakazawaK. (2022). Effect of long-term classical ballet dance training on postactivation depression of the soleus hoffmann-reflex. https://doi.org/10.1123/mc.2021-0079
29.
PalmieriR. M.IngersollC. D.HoffmanM. A. (2004). The hoffmann reflex: Methodologic considerations and applications for use in sports medicine and athletic training research. Journal of Athletic Training, 39(3), 268–277. https://pmc.ncbi.nlm.nih.gov/articles/PMC522151/
30.
PhadkeC. P.FlynnS. M.ThompsonF. J.BehrmanA. L.TrimbleM. H.KukulkaC. G. (2009). Comparison of single bout effects of bicycle training versus locomotor training on paired reflex depression of the soleus H-reflex after motor incomplete spinal cord injury. Archives of Physical Medicine and Rehabilitation, 90(7), 1218–1228. https://doi.org/10.1016/j.apmr.2009.01.022
SteffenT.SeneyM. (2008). Test-Retest reliability and minimal detectable change on balance and ambulation tests, the 36-item short-form health survey, and the unified Parkinson disease rating scale in people with parkinsonism. Physical Therapy, 88(6), 733–746. https://doi.org/10.2522/ptj.20070214
33.
SteinR. B.EstabrooksK. L.McGieS.RothM. J.JonesK. E. (2007). Quantifying the effects of voluntary contraction and inter-stimulus interval on the human soleus H-reflex. Experimental Brain Research, 182(3), 309–319. https://doi.org/10.1007/s00221-007-0989-x
34.
Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles. (n.d.). [Dataset]. http://www.seniam.org/
35.
TennigloM. J. B.NeneA. V.RietmanJ. S.BuurkeJ. H.PrinsenE. C. (2023). The effect of botulinum toxin type A injection in the rectus femoris in stroke patients walking with a stiff knee gait: A randomized controlled trial. Neurorehabilitation and Neural Repair, 37(9), 640–651. https://doi.org/10.1177/15459683231189712
36.
TrimbleM. H.KukulkaC. G.BehrmanA. L. (1998). The effect of treadmill gait training on low-frequency depression of the soleus H-reflex: Comparison of a spinal cord injured man to normal subjects. Neuroscience Letters, 246(3), 186–188. https://doi.org/10.1016/S0304-3940(98)00259-6
37.
TrompettoC.MarinelliL.MoriL.CannevaS.ColombanoF.TraversoE.CurràA.AbbruzzeseG. (2014). The effect of age on post-activation depression of the upper limb H-reflex. European Journal of Applied Physiology, 114(2), 359–364. https://doi.org/10.1007/s00421-013-2778-5
38.
TrompettoC.MarinelliL.MoriL.CossuE.ZilioliR.SimoniniM.AbbruzzeseG.BarattoL. (2013). Postactivation depression changes after robotic-assisted gait training in hemiplegic stroke patients. Gait & Posture, 38(4), 729–733. https://doi.org/10.1016/j.gaitpost.2013.03.011
YangY.XiaoJ.SongW. (2015). Post-activation depression of the lower extremities in stroke patients with spasticity and spastic equinovarus deformity. Arquivos De Neuro-Psiquiatria, 73(6), 493–498. 10.1590/0004-282X20150052.
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