Eligibility Criteria:
Inclusion Criteria:
1. Subacute (\> 4 weeks) or chronic type II whiplash associated disorder. Neck pain and headache following motor vehicle accident with reduced range of motion \& point tenderness.
2. Diagnosis of cervicogenic headache as defined by Cervicogenic Headache International Study Group criteria.
3. Headache frequency of at least one per week since the whiplash injury.
4. Headache intensity of greater than 2/10 on the NPRS.
5. Neck pain intensity of greater than 2/10 on the NPRS.
6. Neck Disability Index score of greater than 10/50 on the NDI.
Exclusion Criteria:
1. WAD I (neck pain, but no physical signs), WAD III (neck pain and neurological signs), WAD IV (neck pain + fracture/dislocation).
2. Positive screen for cervical radiography (Canadian C-Spine Rules).
3. Bilateral headaches (typical of tension type headaches).
4. Diagnosis / signs \& symptoms of concussion (confusion, disorientation, or impaired consciousness; loss of memory for events immediately before or after the MVA; and one or more of the following: nausea, vomiting, visual disturbances, vertigo, gait and/or postural imbalance, and impaired memory and/or concentration).
5. Diagnosis of fibromyalgia.
6. Presence of any of the following atherosclerotic risk factors: hypertension, diabetes, heart disease, stroke, transient ischemic attack, peripheral vascular disease, smoking, hypercholesterolemia, or hyperlipidemia.
7. Red flags noted in the patient's Neck Medical Screening Questionnaire (i.e., tumor, fracture, metabolic diseases, RA, osteoporosis, prolonged history of steroid use, etc.).
8. Diagnosis of cervical spinal stenosis.
9. Bilateral upper extremity symptoms.
10. Evidence of central nervous system involvement, to include hyperreflexia, sensory disturbances in the hand, intrinsic muscle wasting of the hands, unsteadiness during walking, nystagmus, loss of visual acuity, impaired sensation of the face, altered taste, the presence of pathological reflexes (i.e. positive Hoffman's and/or Babinski reflexes).
11. Two or more positive neurologic signs consistent with nerve root compression, including any two of the following:
1. Muscle weakness involving a major muscle group of the upper extremity.
2. Diminished upper extremity deep tendon reflex of the biceps, brachioradialis, triceps or superficial flexors
3. Diminished or absent sensation to pinprick in any UE dermatome.
12. Prior surgery to the head, neck, or thoracic spine.
13. Physical therapy or chiropractic treatment for neck pain and/or headache in the past 3 months.
14. Any condition that might contraindicate spinal manipulative therapy or dry needling.