Abstract
Purpose: The aim of this study was to determine if chiropractic manipulation had an effect
on knee valgus during the landing of a counter movement jump (CMJ) in female athletes. It
also aimed to determine any biomechanical advantage obtained as a result of the
chiropractic manipulation that would enable the female athlete to improve the height and
hence overall performance of the CMJ.
Methods: Thirty female participants between the ages of 18 and 35 years old who
participated in sports that involved jumping were divided into 2 groups. Each participant
performed 3 CMJs, which were recorded by a video camera, and the height of the CMJ
was measured. Group 1 was motion palpated for lumbosacral restrictions and manipulated
accordingly, whereas Group 2 had a 5 minute rest period. After intervention, the
participants performed 3 more CMJs that were again recorded and measured. Dartfish
software was used to measure the angle of knee valgus on the video footage. Participants
were treated once a week for 4 weeks.
Results: Knee valgus angles – With regard to the immediate effect of the interventions,
Group 1 clinically displayed a larger decrease in knee valgus angle than Group 2.
Statistically in Group 1, visit 1 (left knee) and visit 4 (right knee) displayed a significant
decrease (P≤0.05). In terms of the medium term effect, Group 1’s decrease in knee valgus
angle was clinically and statistically significant (P=0.036 (left knee); P=0.038 (right knee)).
CMJ height – In the immediate term, Group 1 displayed a clinically and statistically
significant increase in CMJ height at all 4 visits (P<0.05). In the medium term, Group 1
again displayed an increase that was both clinically and statictically relevant (P=0.000),
whereas Group 2 had an overall decrease in CMJ height in the medium term.
Conclusion: This study has shown that chiropractic manipulation may aid in decreasing
knee valgus angles, therefore this may reduce the risk of female athletes sustaining
excessive knee valgus related injuries. Chiropractic manipulation also caused the CMJ
height to increase, therefore possibly improving the overall CMJ performance, which may
provide the female athlete with a competitive advantage.
M.Tech. (Chiropractic)