4Merritt LG,Merritt CM. The gym ball as a chair for the back pain patient:A two case report. J Can .Chiropr Assoc,2007,51 (1) : 50-55.
5Petrofsky JS,Batt J,Davis N,et al. Core muscle activity during exercise on a mini stability ball compared with abdominal crunches on the floor and on a Swiss ball. Appl Res,2007,7(3 ) :255-272.
6I Marshall PW,Murphy BA. Core stability exercises on and off a Swiss ball. Arch Phys Med Rehabil,2005,86(2): 242-249.
7Liebenson C. Rehabilitation of the Spine: A Practitioner's Manual(2nd Edition). J Alt Compl Meal,2006,12(9): 937-938.
8Waddell G, Somerville D,Henderson I,etal. Objective clini cal evaluation of physical impairment in chronic low back pain. Spine, 1992,17:617-628.
9Beruskens AJ,de Vet HC,Koke AJ,et al. Measuring the functional status of patients with low back pain. Assessment of the quality of four disease=specific questionnaires. Spine, 1995,20(9): 1017-1028.
10Richardson C,Jull G,Hodges P. Therapeutic exercise for spinal segmental stabilization in low back pain:scientific basis and clinical approach. Churchill Livingstone.Edinburgh, 1999. 153.
