A Review on Locomotor Training after Spinal Cord Injury: Reorganization of Spinal Neuronal Circuits and Recovery of Motor Function

Table 1

Summary of neuronal activity changes in SCI after locomotor training^#.

(a)

Neuronal activity	AIS A/B		AIS C		AIS D
	Seated	Stepping	Seated	Stepping	Seated	Stepping
Soleus H-reflex phase-dependent modulation	NA	stance phase; swing phase	NA	swing phase	NA	swing phase
Homosynaptic depression	Restored	NA	Restored	NA	Restored	NA
Presynaptic inhibition of Ia afferents	No change	Not tested	Restored	stance phase; swing phase	Restored	late stance; swing-to-stance transition
Reciprocal Ia inhibition	Restored	Not tested	Restored	stance phase; swing phase	Restored	stance phase; swing phase
Nonreciprocal Ib inhibition	Restored	Not tested	No change	No change in stance; early swing; late swing	Restored	stance phase
Long-latency flexor reflexes	R-Leg; L-Leg	Improved	R-Leg; L-Leg	Improved	R-Leg; L-Leg	Improved
Short-latency flexor reflexes	Reappeared in R-Leg	Phase-dependent modulation emerged in R-Leg	Reappeared in R-Leg	Phase-dependent modulation emerged in R-Leg	Reappeared in both legs	Phase-dependent modulation emerged

(b)

Neuronal activity	AIS A/B		AIS C		AIS D
	Seated	Standing	Seated	Standing	Seated	Standing
Soleus motoneuron excitability (Hmax)	No change in R/L-Legs	No change in R/L-Legs	No change in R-Leg; L-Leg	R/L-Legs	R-Leg; No change in L-Leg	No change in R/L-Legs
H-threshold	No change in R/L-Legs	No change in R/L-Legs	No change in R/L-Legs	No change in R/L-Legs	R-Leg; No change in L-Leg	L-Leg; No change in R-Leg

Neuronal activity changes after locomotor training in people with SCI are from authors’ recent published work [21, 54, 72, 90, 141]. R: right; L: left; and NA: not applicable; symbols / indicate increased or decreased neuronal activity. refers to neuronal activity changes.