Swiss ball exercises improve muscle strength and walking performance in ankylosing spondylitis: a randomized controlled trial

The purpose was to evaluate the effectiveness of a progressive muscle strengthening program using a Swiss ball for AS patients.Sixty patients with AS were randomized into the intervention group (IG) or the control group (CG). Eight exercises were performed by the IG patients with free weights on a Swiss ball two times per week for 16 weeks. The evaluations were performed by a blinded evaluator at baseline and after 4, 8, 12 and 16 weeks using the following instruments: the one-repetition maximum test (1 RM), BASMI, BASFI, HAQ-S, SF-36, 6-minute walk test, time up and go test, BASDAI, ASDAS, ESR and CRP dosage and Likert scale.There was a statistical difference between groups for: strength (1 RM capacity) in the following exercises: abdominal, rowing, squat, triceps and reverse fly (p<0.005); 6-minute walk test (p<0.001); timed up and go test (p=0.025) and Likert scale (p<0.001), all of them with better results for the IG. No differences were observed between the groups with respect to the functional capacity evaluation using the BASFI, HAQ-S, BASMI, SF-36, TUG, ASDAS, ESR and CPR dosage.Progressive muscle strengthening using a Swiss ball is effective for improving muscle strength and walking performance in patients with AS.