Modified Biering-Sorenson Protocol Changes Joint Contributions to Total Support in Individuals with a History of Anterior Cruciate Ligament Reconstruction During Drop Vertical Jump Landings.

The study was a single-group pretest-posttest design with no control group, so it cannot determine if the observed responses to fatigue would have occurred prior to injury or in healthy individuals. The sample size was small (n=19), which limits the generalizability of the findings to the broader ACL reconstruction population. Electromyography data were not collected, so it is unknown if the unchanged kinematics were due to compensatory increased neural drive to other muscles. The participants were cleared for sport and had an average time since surgery of nearly five years, so findings may not apply to those earlier in rehabilitation or with lower function.

The authors have no relationships or activities that could appear to have influenced the submitted work.

Do not assume that hip extensor fatigue causes obvious changes in knee or ankle joint angles during landing. The study found no significant changes in single-joint kinematics after fatigue; the effect was only seen in the redistribution of forces across joints (total support moment) and the injured limb's inherent asymmetry.