An accessory movement is a lift that targets muscles that provide vital assistance during the larger lifts that get you the most bang for your buck. For example, the lats are the primary movers in a chin-up, but they can’t perform without the assistance of the traps. Adding a kettlebell angled press to your workout to strengthen the lower and middle traps will enhance the performance of the lats, enabling you to do more chin-ups with better form in the long term.
Accessory moves help promote muscular balance and overall strength, and when programmed properly, they also help prevent injury. Add these moves into your workouts, scheduling them after your big movement patterns, and seal up those weak links in your movement chains once and for all.