M. Haas et al., SHORT-TERM RESPONSIVENESS OF MANUAL THORACIC END PLAY ASSESSMENT TO SPINAL MANIPULATION - A RANDOMIZED CONTROLLED TRIAL OF CONSTRUCT-VALIDITY, Journal of manipulative and physiological therapeutics, 18(9), 1995, pp. 582-589
Objective: To evaluate the short-term responsiveness of rotatory thora
cic end-play assessment to spinal manipulation and, thereby, motion pa
lpation construct validity. Design: Prospective, single-blind, randomi
zed, controlled trial (randomized blocks design). Setting: Laboratory,
Center for Technique Research. Participants: Sixty first-year chiropr
actic college student volunteers; seventy-three possible candidates we
re screened. Interventions: The treatment group received manual high-v
elocity, low-amplitude rotatory manipulation. The control group receiv
ed no intervention to minimize nonspecific effects of sham treatment.
Main Outcome Measures: End-play response, defined as the change from r
estricted to normal end play immediately after intervention. Responsiv
eness, defined as the percentage of the end-play response attributable
to spinal manipulation: relative response attributable to the maneuve
r, RRAM = (treatment group response - control group response)/treatmen
t group response. Results: Ten percent of the tests were positive for
restriction of end play in left or right rotation from T3-T4 to T12-L1
, the average rate was 2.1 restrictions per subject (SD = 1.4). End-pl
ay response was 60% in the treatment group, in contrast to the 37% res
ponse in the control group (z = 1.86, p = .04). More than a third of t
he response in the treatment group was attributable to spinal manipula
tion (RRAM = 39%). For one examiner, RRAM = 51%. Mild symptomatology d
id not affect responsiveness. Conclusions: The data suggest a moderate
short-term responsiveness of rotatory thoracic end-play restriction t
o spinal manipulation, hence it has utility as a posttreatment evaluat
ive test. This study was the first to use an external standard (manipu
lation) to demonstrate that segmental end-play restriction changes, he
nce end-play restriction itself, are detectable in human subjects with
manual palpation by chiropractors. Further research is required to de
termine the generalizability of the study findings.