June 2018

The Effect of CAI on Landing/Cutting Lower-Extremity Kinematics, EMG, and GRF

iStockphoto.com 656642576

In the poster, Altered Movement Neuromechanics during Jump Landing and Cutting in Patients with Chronic Ankle Instability,3 Hyunsoo Kim, assistant professor of the Department of Kinesiology, West Chester University, West Chester, PA, and colleagues looked at altered movement pattern in patients with CAI to examine biomechanical factors for CAI.

“Results of most previous studies primarily examining a static measure of sensorimotor impairments may not fully provide dynamic characteristics of altered movement strategies during functional tasks,” Kim said. “To bridge the gap between sensorimotor impairments and the mechanisms of CAI, it is imperative to comprehensively evaluate biomechanical and neuromuscular patterns during a sport maneuver.”

The authors believe this is the first study to comprehensively analyze movement strategies of lower extremity kinetics (ground force reaction), kinematics (angle), and EMG activation with a large sample size (total 200 subjects) during multi-planar jump landing/cutting task using a novel functional statistical analysis approach.

“We found CAI patients utilized more proximal (hip) joints with heightened corresponding muscle activation to compensate for an unstable distal (ankle) joint (eg, more inversion and less dorsiflexion angle) in an attempt to reduce ground impact force,” Kim said. “CAI patients demonstrated a more vertically upright position of the femur (less abducted position), which may help stabilize the downward motion of their center of mass in the sagittal plane prior to cutting to the contralateral side.”

Although a relationship between risk of lateral ankle sprain and a hip dominant landing/cutting strategy should be examined in a prospective study, as both hip abductor and extensor strength is present in CAI patients, Kim noted clinicians should focus on regaining both hip abductor and extensor muscle strength in addition to strength gains in ankle musculature.

“More importantly, during and/or after the strengthening program, interventions should aim at re-programming of neuromuscular control during landing/cutting by optimally distributing ground impact across ankle, knee, and hip joints,” Kim said.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.