From: Relative effectiveness and adverse effects of cervical manipulation, mobilisation and the activator instrument in patients with sub-acute non-specific neck pain: results from a stopped randomised trial
Adverse symptom
Activator
Manipulation
Mobilisation
Mildly increased neck pain
7
4
2
Mild radiating pain
5
1
Mild arm weakness
0
Mild arm numbness
Mild headache
3
Mild fatigue
Mild dizziness
Mild muscle twitching