Prior studies indicate thoracic spinal
manipulative therapy (SMT) improves
shoulder pain and disability. However, these studies are limited by no control or
sham-treatment group. A valid
sham comparator for thoracic SMT is needed. Subjects (n=69) without
shoulder pain were randomized to one of three groups: thoracic SMT,
sham-SMT, or
sham-ultrasound; and told they were randomized to
manual therapy, range of motion, or ultrasound respectively. Perceived effects of the treatment on shoulder motion,
pain, and functional were questioned before and
after treatment. Believability was assessed by asking if the subject believed they received the active or inactive intervention. Shoulder active range of motion (AROM) was measured with a digital inclinometer before and
after treatment by a blinded examiner. Believability of treatment was not significantly different between the SMT and
sham-SMT (p=0.12), but a greater proportion (p=0.03) believed they received the active treatment in the SMT group (78.3%) as compared to the
sham-ultrasound (47.8%). No differences in perception of treatment effects between the treatment groups were detected (p≥0.1). Shoulder internal rotation AROM increased in the thoracic SMT group (mean difference=3.7°; p=0.006), but did not change within the
sham-SMT (p=0.44) or
sham-ultrasound (p=0.18) groups. Shoulder flexion did not change within any group. These preliminary results indicate the
sham-SMT is an adequate
sham comparator for SMT with similar expectations and believability as SMT active treatment. The
sham-SMT had an inert effect on shoulder AROM.
Sham-ultrasound was not believable as an active treatment. Future studies need to validate these results in patients with
shoulder pain.