Grube B, Grunwald J, Krug L, Staiger C.
Efficacy of a comfrey root (Symphyti offic. radix) extract ointment in the treatment
of patients with painful osteoarthritis of the knee:
results of a double-blind, randomised, bicenter, placebo-controlled trial.
Phytomedicine 2007;14:2-10.

Grant KE. Massage safety: injuries reported in MEDLINE as related to the practice
of therapeutic massage - 1965 to 2003.

Pearlman AI, Sabina A, Williams A-L, Njike VY, Katz DL.
Massage therapy for osteoarthritis of the knee.
Archives of Internal Medicine 2006;166:2533-2538

Hsieh LL-C, Kuo C-H, Lee LH, Yen AM-F, Chien K-L, Chen T H-H.
Treatment of low back pain by acupressure and physical therapy: randomised controlled trial.
BMJ, doi:10.1136/bmj.38744.672616.AE (published 17 February 2006).

Hsu C-C, Ho M-C, Lin L-C, Su B, Hsu M-C.
Amercian ginseng suplementation attentuates creatine kinase level induced by submaximal exercise in human beings.
World Journal of Gastroenterology 2005;11(34):5327-5331.

Vickers A, Zollman C. Massage therapies.
British Medical Journal 1999;319:1254-1257.

Touch Research Institutes, University of Miami, USA