The importance of recognizing a closed-chain activity lies in the fact that the motions of multiple joints are coupled. Weakness at any one joint will consequently limit performance of the entire movement.

This article provides an understanding of the role the core plays during execution of athletic movements, as well as provides evidence-based concepts that help to strengthen the core and maximize movement performance.

This excerpt from NSCA’s Essentials of Personal Training discusses the importance of education on proper running surfaces, appropriate footwear, and the benefits of cross-training in addressing overuse of the knee.

Integrating unbalanced load training into a strength or hypertrophy phase, or any workout program, can add a tremendous amount of demand on the lateral aspects of the core to help the athlete develop a strong core. Using unbalanced load training may help produce increases in athleticism, balance, and motor coordination without sacrificing strength or explosiveness.

Multidirectional ground reaction forces (GRFs) and jump tests within baseball pitchers provide insight into athletic ability and coordination to produce lower-body force and power. Lower-body power is a biomechanical feature that denotes physiological capacity through dynamic and passive tissue stretch-shortening in transferring energy from the ground through the kinetic chain. Optimized lower-body power may lessen the magnitude of forces on the upper extremity. Insufficient lower-body power may create a greater risk of upper-body injury. Lower-body power and its relationship to ball velocity have been minimally investigated, yet some research points to a correlation between jumping ability and fastball velocity. Because pitching is unilateral, practitioners should consider unilateral jumps to determine the extent of bilateral asymmetry or stride to drive leg differences that can guide training to remediate deficiencies. The purposes of this brief review are to (a) examine factors that influence vertical jump performance among baseball players, (b) examine research on pitching multidirectional GRFs, and (c) examine literature concerning jump performances to baseball pitching performance. Collectively, this review can assist coaches and practitioners in lower-body power testing and training for baseball pitchers.

This excerpt from Developing the Core briefly defines closed- and open-chain exercises and their respective roles in training.

The purpose of this article is to present a sample injury prevention program with a specific emphasis on lower body posterior chain development throughout competitive and non-competitive college lacrosse seasons.

The exerciser with 8 to 12 months of training experience can begin to include exercise complexes that combine trunk movement patterns with multijoint movements. Single-plane and multiplane movements can be performed using both open- and closed-chain exercises.

This short excerpt from Developing the Core details the importance of training the core musculature in tennis athletes.

This article will focus on three common areas of injuries that occur with ice hockey players and some recommended strategies for the strength and conditioning professional.