Table 1.

Characteristics of patients with non specific chronic low back pain before treatment in continuous ultrasound and placebo ultrasound groups

Parameter	Continuous US*		Placebo US		P value***
	(n=25)		(n=25)
	Mean	SD	Mean	SD
Age(years)	31.4	12.3	37.4	11.9	.09
Onset since first episode(years)	5.8	4.1	8.1	4.7	.08
BMI**	24.4	4.1	25.3	3.5	.39
Sex	25%female _ 75%male		50%female _ 50%male

* Ultrasound.

** Body Mass Index.

***p values are for baseline differences between the two groups. Significance level ≤ .05.