Female Overrepresentation in Low Back-Related Leg Pain: A Retrospective Study of the Autonomic Response to a Minimally Invasive Procedure

Figures & data

Table 1 Baseline Characteristics of Study Participants (n=48)

Data	LBLP
Female sex [%]	64.6
Age, mean (SD) [y]	47.5 (8.6)
BMI, mean (SD)	25.7 (4.5)
Symptoms duration [y]	5.3 (5.7)
Leg pain above knee [%]	36.6
Leg pain below knee [%]	63.4
Leg pain below ankle [%]	41.5

Figure 1 Gender proportion for patients positive and negative for nociplastic pain (NP).

Table 2 Clinical Data and Standard LBLP Diagnostic Parameter Distribution for Patients Positive and Negative for Nociplastic Pain

Positive Results		Number and Percentage of LBLP Subjects (%)
		NP (+) Patients n=21	NP (–) Patients n=27	p-value and 95% and CI (chi^2 Test for Proportions)
Leg pain location	Above knee	9 (44.4)	8 (30.4)	0.53 CI (−20.6, 48.6)
	Below knee	12 (55.6)	19 (69.6)	0.53 CI (−48.6, 20.6)
	Below ankle	10 (50)	10 (34.8)	0.51 CI (−19.9, 50.4)
Functional examination	SLR ≤45°	11 (52.5)	10 (37)	0.41 CI (−17.0,47.6)
	SLR >45°	10 (47.5)	17 (63)	0.41 CI (−47.6,16.7)
	xSLR	0	1 (3.7)	0.95 CI (−4.5,7.1)
	Bragard (+)	8 (38.1)	16 (59.2)	0.24 CI (−53.2,10.9)
	Slump (+)	5 (23.8)	8 (29.6)	0.87 CI (−35.1,23,5)
	Bragard and Slump (+)	2 (9.5)	8 (29.6)	0.19 CI (−45.7,5.4)
Pinprick	L2	1 (5)	1 (3.7)	0.98 CI (−11.6,13.7)
	L3	1 (4.8)	3 (11.1)	0.77 CI (−25.5,12.8)
	L4	6 (28.6)	4 (14.8)	0.41 CI (−14,41.5)
	L5 S1	2 (9.5)	5 (18.5)	0.65 CI (−32.5,14.5)
		1 (4.8)	3 (11.1)	0.75 CI (−25.5,12.8)
Temperature impairment	L2	0	1 (3.8)	1.00 CI (−14.5,7.1)
	L3	0	0	NA
	L4	0	0	NA
	L5	4 (20)	0	0.06 CI (−2,42)
	S1	0	1 (3.8)	1 CI (−14.5,7.1)
Vibratory sensation impairment		0	0	NA
Tendon reflex	Patellar impaired	7 (33.3)	10 (37)	1 CI (−34.6,27.2)
	Patellar absent	0	0	NA
	Achilles impaired	11 (52.4)	17 (63)	0.65 CI (−42.9,21.7)
	Achilles absent	5 (23.8)	4 (14.8)	0.66 CI (−17.9,35.8)
Pain over the lumbar spinous processes		5 (25)	4 (15.4)	0.66 CI (−18.3,37.5)
Root compression	L4	2 (9.5)	6 (22.2)	0.40 CI (−0.37, 0.12)
	L5	7 (33.3)	5 (18.5)	0.34 CI (−0.33, 0.19)
	S1	6 (28.6)	5 (18.5)	0.61 CI (−0.18, 0.39)
Disc prolapse	L3-L4	7 (33.3)	6 (22.2)	0.57 CI (−0.19, 0.41)
	L4-L5	11 (52.4)	15 (55.6)	0.99 CI (−0.35, 0.28)
	L5-S1	13 (61.9)	15 (55.6)	0.86 CI (−0.26, 0.39)

Abbreviations: SLR, straight leg test; xSLR, cross straight leg test; NP, (+) nociplastic pain positive; NP, (–) nociplastic pain negative; NA, not applicable.

Figure 2 Proposal of predictors for NP presence among LBLP subjects.

Figure 3 Probabilities of NP among LBLP subjects predicted by the logistic regression model.