The effect of thoracic spinal manipulation on trunk motion in elite sprint kayakers: A pilot cross-over trial

OBJECTIVES A critical aspect of flatwater sprint kayaking performance is paddling technique, particularly the role of trunk motion. As spinal manipulation (SM) increases joint range of motion, the aim of this study was to investigate if SM can alter trunk motion during paddling in elite sprint kayakers. METHODS Seventeen elite sprint flatwater kayakers paddled at 60 strokes/minute for 5-minutes on a kayak ergometer before and after intervention on two separate occasions. Participants received both stretching (S: pre-determined 5 minute stretching routine) and spinal manipulation (SM: two multi-joint (group) thoracic manipulations) intervention, administered in reverse order at the second session. Three-dimensional kinematics were recorded (Qualisys) and analysed using Visual 3D software (CMotion). Repeated measures factorial analyses of variance were used to determine significant changes. RESULTS Whilst no overall effect of intervention on joint angles at L5/S1, T12/L1 or neck-trunk was observed, post hoc analyses revealed changes in a number of movements and stroke stages following SM compared to S. These included: greater neck-trunk rotation at the exit/horizontal stage of the stroke (p=0.001); less T12/L1 extension and greaterT12/L1 lateral flexion and neck-trunk lateral flexion at stroke entry on the right compared to the left; greater L5/S1 extension and T12/L1 lateral flexion at vertical (p=0.001); and greater T12/L1 extension with a more neutral lateral flexion position at exit/horizontal (p<0.05). CONCLUSION Elite sprint flatwater kayakers employ an asymmetrical trunk motion during paddling. SM is capable of altering this motion. Further research is required to investigate whether these changes are maintained at higher stroke rates.