Short-term responsiveness of manual thoracic end-play assessment to spinal manipulation: a randomized controlled trial of construct validity.
OBJECTIVE
To evaluate the short-term responsiveness of rotatory thoracic end-play assessment to spinal manipulation and, thereby, motion palpation construct validity.


METHODS
Prospective, single-blind, randomized, controlled trial (randomized blocks design).


METHODS
Laboratory, Center for Technique Research.


METHODS
Sixty first-year chiropractic college student volunteers; seventy-three possible candidates were screened.


METHODS
The treatment group received manual high-velocity, low-amplitude rotatory manipulation. The control group received no intervention to minimize nonspecific effects of sham treatment.


METHODS
End-play response, defined as the change from restricted to normal end play immediately after intervention. Responsiveness, defined as the percentage of the end-play response attributable to spinal manipulation: relative response attributable to the maneuver, RRAM = (treatment group response--control group response)/treatment 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-play response was 60% in the treatment group, in contrast to the 37% response in the control group (z = 1.86, p = .04). More than a third of the response in the treatment group was attributable to spinal manipulation (RRAM = 39%). For one examiner, RRAM = 51%. Mild symptomatology did not affect responsiveness.


CONCLUSIONS
The data suggest a moderate short-term responsiveness of rotatory thoracic end-play restriction to spinal manipulation, hence it has utility as a posttreatment evaluative test. This study was the first to use an external standard (manipulation) to demonstrate that segmental end-play restriction changes, hence end-play restriction itself, are detectable in human subjects with manual palpation by chiropractors. Further research is required to determine the generalizability of the study findings.
Haas
M
M
Research Division, Western States Chiropractic College, Portland, Oregon 97230, USA.
Panzer
D
D
Peterson
D
D
Raphael
R
R
D000328:Adult; D000704:Analysis of Variance; D002684:Chiropractic / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016037:Single-Blind Method; D013122:Spinal Diseases / Q000628:therapy*; D013904:Thoracic Vertebrae; D016896:Treatment Outcome