Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effect of Yoga Vs. Stretching on Chronic Back Pain
Brief Summary: This study will compare the effectiveness of yoga classes, exercise classes, and a self-care book in the management of pain and function for people with low back pain.It will also for physical, psychological and physiological factors associated with improvement in back pain.


Options:
A: Inclusion Criteria:

* Sub-Acute and chronic low back pain (Defined as current episode more than 6 weeks duration.)
* Quebec Task Force classifications 1, 2, 3 and 4. (This includes patients with back pain, stiffness or tenderness, with or without musculoskeletal signs and neurological signs.{1570})
* 65 years of age and older
* Independent ambulation
* Community dwelling (residency outside nursing home)
* Score of 20 or more on Folstein Mini-Mental State Examination{13246}
* Stable prescription medication plan (no changes in prescription medications that affect musculoskeletal pain in previous month)

Exclusion Criteria:

* Referred low back pain from local joint lesions of the lower extremities or from visceral diseases
* Significant infectious disease Determined by history or by referral to supplementary diagnostic tests
* Ongoing treatment for low back pain by other health care providers
* Mean baseline low back pain score of 20 percentage points or less
* Contraindications to exercise Determined by history or by referral to supplementary diagnostic tests (i.e., uncontrolled arrhythmias, third degree heart block, recent ECG changes, unstable angina, acute myocardial infarction, acute congestive heart failure, cardiomyopathy, valvular heart disease, poorly controlled blood pressure, uncontrolled metabolic disease
* Contraindications to spinal manipulation (i.e. Progressive neurological deficits blood clotting disorders; infectious and non-infectious inflammatory or destructive tissue changes of the spine; severe osteoporosis)
B: Inclusion Criteria:

* Patients with chronic non-specific low back pain diagnosed and at least 12 weeks of mechanical pain.

Exclusion Criteria:

* Patients:
* With arterial hypertension diagnosed.
* With progressive neurological deficits.
* Pregnant or suspect that they are pregnant.
* With psychological or psychiatric process diagnosed.
* Under analgesic treatment.
C: Inclusion Criteria:

* non- specific low back pain,
* 18-60 years old,
* \> 90 points on the OMPSQ screening questionnaire for yellow flags and sufficient understanding of the Swedish language

Exclusion Criteria:

* presence of so called Red flags,
* pregnancy,
* comorbidities affecting the ability to perform the interventions,
* presently on sick leave for \> 8 weeks,
* ongoing regular weekly yoga practice or strength training.
D: Inclusion Criteria:

* Group Health Cooperative enrollee
* Uncomplicated low back pain
* At least moderate pain levels

Exclusion Criteria:

* Sciatica persisting 3 or more months after physician visit
* History of cancer (other than nonmelanoma skin cancer)
* Severe disk problems
* Unstable medical conditions
* Back surgery within past 3 years
* Physically unable to do the yoga or exercise classes and homework
* Unable to attend classes
* Currently doing yoga
* Taken yoga or exercise class for back pain within past year
* Currently in litigation for back pain
* Seeking other treatment for back pain

Answer: D