Learning spinal manipulation: the effect of expertise on transfer capability.
OBJECTIVE
Transfer capability represents the changes in performance in one task that result from practice or experience in other related tasks. Increased transfer capability has been associated with expertise in several motor tasks. The purpose of this study was to investigate if expertise in spinal manipulation therapy, assessed in groups of trainees and experienced chiropractors, is associated with increased transfer capabilities.


METHODS
Forty-nine chiropractic students (fifth- and sixth-year students) and experienced chiropractors were asked to perform blocks of 10 thoracic spine manipulations in 3 different conditions: preferred position and table setting, increased table height, and unstable support surface. Spinal manipulations were performed on a computer-connected device developed to emulate a prone thoracic spine manipulation. Thrust duration, thrust force rate of force application, and preload force were obtained for each trial and compared across groups and conditions.


RESULTS
Results indicated that both expertise and performance conditions modulated the biomechanical parameters of spinal manipulation. Decreased thrust duration and increased rate of force application were observed in experienced clinicians, whereas thrust force and thrust rate of force application were significantly decreased when task difficulty was increased. Increasing task difficulty also led to significant increases in performance variability.


CONCLUSIONS
Overall, this study suggests that when instructed to perform spinal manipulation in a challenging context, trainees and experts choose to modulate force to optimize thrust duration, a characteristic feature of high-velocity, low-amplitude spinal manipulation. Given its known association with motor proficiency, transfer capability assessments should be considered in spinal manipulative therapy training.
Full Professor, Département des sciences de l'activité physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec. Electronic address: Martin.descarreaux@uqtr.ca.
Martin
M
Descarreaux
Full Professor, Département des sciences de l'activité physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec.
Claude
C
Dugas
Enseignant, Domaine des sciences cliniques et examens du patient, Institut Franco-Européen de Chiropratique (IFEC), Toulouse, France.
Julien
J
Treboz
Enseignant, Domaine d'intégration des savoirs et savoirs faire en chiropraxie, Institut Franco-Européen de Chiropratique (IFEC), Toulouse, France.
Charlène
C
Cheron
Postdoctoral Fellow, Département des sciences de l'activité physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec.
François
F
Nougarou
D000328:Adult; D002684:Chiropractic / Q000193:education*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D020393:Manipulation, Spinal; D011361:Professional Competence; D013336:Students, Health Occupations; D055815:Young Adult
Chiropractic; Learning; Manipulation; Spinal