Supra-threshold scaling, temporal summation, and after-sensation: relationships to each other and anxiety/fear

Figures & data

Table 1 Descriptive statistics

Variable	Pooled (n = 120)
Age (years)	23.6 (3.2)
Sex (# female)	70% (84/120)
Education (years)	16.3 (1.7)
Fear (0–100 VAS)	25.7 (18.0)
Anxiety (0–100 VAS)	25.7 (20.7)
Thermal threshold (C)	43.7 (3.4)
Ramp and hold leg (0–100 NRS)	24.3 (19.2)
Ramp and hold trunk (0–100 NRS)	31.5 (21.5)
Ramp and hold arm (0–100 NRS)	27.3 (18.7)
Wind up leg (0–100 NRS)	39.7 (28.3)
Wind up trunk (0–100 NRS)	62.7 (23.4)
Wind up arm (0–100 NRS)	43.7 (27.5)
After-sensations leg (0–100 NRS)	12.9 (16.4)
After-sensations trunk (0–100 NRS)	18.8 (21.4)
After-sensations arm (0–100 NRS)	12.8 (15.4)

Notes: All values reported as mean (±SD) or % (#).

Abbreviations: VAS, visual analog scale; NRS, numerical rating scale; SD, standard deviation. Ramp and hold reported at 47°C only.

Table 2 Correlations among psychophysical measures

	TS-LE	TS-TR	TS-UE	AS-LE	AS-TR	AS-UE
RH-LE	0.61**	0.70**	0.56**	0.53**	0.59**	0.44**
RH-TR	0.62**	0.81**	0.63**	0.50**	0.60**	0.42**
RH-UE	0.67**	0.76**	0.64**	0.52**	0.58**	0.47**
TS-LE				0.67**	0.46**	0.45**
TS-TR				0.54**	0.53**	0.52**
TS-UE				0.54**	0.47**	0.66**

Note:

** P < 0.01.

Abbreviations: RH, ramp and hold (supra-threshold response);TS, temporal summation; AS, after-sensation; LE, lower extremity; TR, trunk; UE, upper extremity.

Table 3 Correlations among psychological measures

	Fear-VAS	Anx-VAS	STAI	FPQ	CAT
Fear-VAS
Anx-VAS	0.79*
STAI	0.08	0.14
FPQ	0.20*	0.25*	0.26*
CAT	0.32*	0.31*	0.19	0.47*
ASI	0.34*	0.49*	0.24*	0.46*	0.26*

Note:

* P < 0.05.

Abbreviations: Fear-VAS, Fear Visual Analog Scale; Anx-VAS, Anxiety Visual Analog Scale; STAI, Spielberger State-Trait Anxiety Inventory; FPQ, Fear of Pain Questionnaire; CAT + Catastrophizing Scale; ASI + Anxiety Sensitivity Index.

Table 4 Correlations among psychophysical measures

	TS-LE	TS-TR	TS-UE	AS-LE	AS-TR	AS-UE	RH-LE	RH-TR	RH-UE
Fear-VAS	0.08	−0.08	0.07	0.06	0.06	−0.03	0.17	0.05	0.06
Anx-VAS	0.20*	0.17	0.05	0.15	0.11	0.04	0.22*	0.17	0.18*
STAI	0.02	−0.02	−0.12	−0.05	0.03	−0.15	0.3*	0.11	0.20
FPQ	0.32**	0.38**	0.23*	0.29**	0.43**	0.23*	0.55**	0.51**	0.47**
CAT	0.24	0.28*	0.01	0.28*	0.34**	0.04	0.31*	0.32*	0.17
ASI	0.27*	0.30*	0.47**	0.19	0.32*	0.16	0.53**	0.45**	0.47**

Notes:

* P < 0.05,

** P < 0.01.

Abbreviations: RH, ramp and hold (supra-threshold response); TS, temporal summation; AS, after-sensation; LE, lower extremity; TR, trunk; UE, upper extremity; Fear- VAS, Fear Visual Analog Scale; Anx-VAS, Anxiety Visual Analog Scale; STAI, Spielberger State-Trait Anxiety Inventory; FPQ, Fear of Pain Questionnaire; CAT + Catastrophizing Scale; ASI + Anxiety Sensitivity Index.

Table 5 Results of psychological predictors of pain measures

Psychophysical measure	Site	R^2	F	p	β
RH	LE	0.45	70.2	0.002
					FPQ = 0.32*
					ASI = 0.29*
					FearVAS = 0.20
					AnxVAS = −0.03
					STAI = 0.13
					CAT < 0.01
	TR	0.32	40.2	0.002
					FPQ = 0.33*
					ASI = 0.27
					FearVAS = −0.13
					AnxVAS = 0.13
					STAI = −0.06
					CAT = 0.10
	UE	0.31	30.9	0.003
					FPQ = 0.31*
					ASI = 0.28*
					FearVAS = −0.08
					AnxVAS = 0.15
					STAI = 0.07
					CAT = −0.09
TS	LE	0.12	0.47	>0.05
					FPQ = 0.05
					ASI = 0.18
					FearVAS = −0.11
					AnxVAS = 0.15
					STAI = −0.08
					CAT = 0.18
	TR	0.29	30.7	0.004
					FPQ = 0.12
					ASI = 0.36*
					FearVAS = −0.14
					AnxVAS = 0.22
					STAI = −0.18
					CAT = 0.14
	UE	0.15	10.6	0.160
					FPQ = 0.09
					ASI = 0.33*
					FearVAS = −0.23
					AnxVAS = 0.13
					STAI = −0.24
					CAT = −0.05
AS	LE	0.15	10.6	>0.05
					FPQ = 0.24
					ASI = 0.07
					FearVAS = 0.01
					AnxVAS = 0.01
					STAI = −0.16
					CAT = 0.17
	TR	0.26	30.2	0.010
					FPQ = 0.36*
					ASI = 0.16
					FearVAS = 0.07
					AnxVAS = −0.09
					STAI = −0.12
					CAT = 0.16
	UE	0.07	0.68	>0.05
					FPQ = 0.10
					ASI = 0.16
					FearVAS = −0.10
					AnxVAS = 0.09
					STAI = −0.20
					CAT < 00.01

Note:

* P < 0.05.

Abbreviations: RH, ramp and hold (supra-threshold response); TS, temporal summation; AS, after-sensation; LE, lower extremity; TR, trunk; UE, upper extremity.