The relationship between drop vertical jump action‐observation brain activity and kinesiophobia after anterior cruciate ligament reconstruction: A cross‐sectional fMRI study

BACKGROUND: Injury and reconstruction of anterior cruciate ligament (ACL) result in central nervous system alteration to control the muscles around the knee joint. Most individuals with ACL reconstruction (ACLR) experience kinesiophobia which can prevent them from returning to activity and is associated with negative outcomes after ACLR. However, it is unknown if kinesiophobia alters brain activity after ACL injury. OBJECTIVES: To compare brain activity between an ACLR group and matched uninjured controls during an action‐observation drop vertical jump (AO‐DVJ) paradigm and to explore the association between kinesiophobia and brain activity in the ACLR group. METHODS: This cross‐sectional study enrolled 26 individuals, 13 with ACLR (5 males and 8 females, 20.62 ± 1.93 years, 1.71 ± 0.1 m, 68.42 ± 14.75 kg) and 13 matched uninjured controls (5 males and 8 females, 22.92 ± 3.17 years, 1.74 ± 0.10 m, 70.48 ± 15.38 kg). Individuals were matched on sex and activity level. Participants completed the Tampa Scale of Kinesiophobia‐11 (TSK‐11) to evaluate the level of movement‐related fear. To assay the brain activity associated with a functional movement, the current study employed an action‐observation/motor imagery paradigm during functional magnetic resonance imaging (fMRI). RESULTS: The ACLR group had lower brain activity in the right ventrolateral prefrontal cortex relative to the uninjured control group. Brain activity of the left cerebellum Crus I and Crus II, the right cerebellum lobule IX, amygdala, middle temporal gyrus, and temporal pole were positively correlated with TSK‐11 scores in the ACLR group. CONCLUSION: Brain activity for the AO‐DVJ paradigm was different between the ACLR group and uninjured controls. Secondly, in participants with ACLR, there was a positive relationship between TSK‐11 scores and activity in brain areas engaged in fear and cognitive processes during the AO‐DVJ paradigm.