Table 2. A simplified injury severity (SIS) scale based on simple observable criteria for assessing initial gross locomotor functional deficits soon after spinal cord injury in rats.

Animals are first assessed by the presence (scores 0–1.5) or absence (scores 2–3) of weight supported hind limb stepping. Those exhibiting weight support are then graded on the basis of the visual severity of any gait abnormality (none, slight or gross). Those without weight support are graded on the basis of how many joints (hip, knee, ankle) they are able to voluntarily flex/extend (none, one or more than 1) when restrained by holding the tail and lifting the hind quarters gently up and lowering back down. Each hindlimb is assessed independently and the average of both recorded. The most equivalent grades on the scale used by Herrmann et al. (2008) and Anderson et al. (2016) are shown on the right.

Simplified Injury Severity (SIS) Grading Scale
Weight support	Stepping pattern	Extend & flex joints	SIS Score	Equivalent Herrmann Grading
YES	Normal	all	0	hindlimb function essentially normal	5
	Slight abnormality	all	1	hindlimb used for weight support and stepping, but obvious disability	4
	Gross abnormality	all	1.5	hindlimb assisted in occasional weight support and plantar placement, but not in stepping	3
NO	No stepping	two or more	2	hindlimb movements obvious, but did not assist in weight support or stepping	2
		one	2.5	little voluntary hindlimb movement	1
		none	3	no voluntary hindlimb movement	0