News & Views from the Editor-in-Chief - L. Bruce Gladden
As usual, I am highlighting three papers in this month's journal. In the first highlight, Semplonius and Willoughby performed a novel examination of the association between sleep quality and physical activity over time in a sample of young adults. Past studies in this field of research have provided mixed results as to whether sleep and physical activity are associated. The results of this study indicate that they are indirectly related through emotion regulation. Specifically, better sleep indirectly predicted more physical activity over time through emotion regulation, and moderate physical activity predicted better sleep over time through emotion regulation. In terms of practical applications, although sleep and physical activity are not directly related, higher scores in both areas promote better outcomes over time.
In a second study of interest this month, Zhou et al. combined measurements of knee function and anatomy to quantify the contribution of the posterior capsule tissue in limiting knee extension after joint immobilization. For this, the authors used an animal model and a comprehensive temporal design including various knee immobilization and remobilization periods. The data showed that the posterior capsule length was not restored by unassisted remobilization after longer durations of immobilization. Additionally, the reduction in length was mainly attributable to the longer femoral side of the posterior capsule. Interestingly, the progressive decrease in capsule length was positively correlated with lack of knee extension as duration of immobilization increased, despite remobilization. These results support the role of the posterior capsule in knee flexion joint contracture and the need for interventions aimed at restoring knee extension when the duration of immobilization exceeds two weeks.
In the third highlighted article, Bowser et al. investigated potential links between excessive vertical impact peak, vertical loading rate, and tibial shock with a variety of overuse running injuries. Specifically, the study's purpose was to examine the short- and long-term effect of a gait retraining program in runners with high impact loading. In addition to reductions in impact loading immediately following the retraining protocol, there was a persistence of decreased vertical impact peaks, vertical loading rates and tibial shock at 1-, 6-, and 12-month follow-ups. The inclusion of real-time feedback, and the sequential reduction of feedback over time in the retraining protocol appeared to be integral components in achieving these long-term changes in gait. Gait retraining aimed at reducing load rates can be a powerful way to help reduce injuries in runners.
L. Bruce Gladden
School of Kinesiology