Neutralizing muscles provide important support during exercise to prevent injury and restrict movement. These muscles are often smaller than the large moving muscles of your body; however, their importance should not be underappreciated or underaddressed in a training program. Adequate training of these muscles will improve your overall strength and further reduce the risk of injury.
According to the "Sports Science Handbook," written by Simon Jenkins, the neutralizing muscle cancels out undesirable movements by contracting. The contraction of the muscle helps control the movement path of the primary muscle by keeping it within certain definable boundaries. A neutralizers may also be classified as stabilizers because it is their ability to keep joints balanced that holds motion along a specific path. Neutralizers should not be confused with synergistic muscles that help produce the desired movement of the lift. Synergists help control the movement path, but they also help with the primary motion you are trying to achieve.
An examination of the classic biceps curl exercise will help you understand the role of a neutralizer during exercises. During the curl, the angle between your forearm and upper arm closes causing your biceps to contract to produce the movement. However, the bicep also causes suprination when contracting. This causes the forearms to rotate so that your palms face upward. To prevent or neutralize this motion from happening, the pronator teres, which is located in your forearm, activates to counter and neutralize this function of your biceps.
Training your neutralizing muscles involves performing exercises in ways that challenge your ability to control the weight your are lifting through different movement types. Performing exercises on a surface that requires stabilization with train both neutralizing and stabilizing muscles related to the specific movement. Since these muscles are smaller and related to postural control, you should use a high number of repetitions during your exercise to elicit maximal training of your neutralizers. Generally, performing at least 20 repetitions of a particular exercise should begin to challenge the neutralizing muscles because your primary muscles will become fatigued and less able to control their movement path.
Training the neutralizers will make you strong and faster while preventing injuries. For example, imagine playing a game of soccer and you plant your foot in the ground to make a swift turn. When you plant, your neutralizers act to make sure your primary muscles activate in a way that maximizes the reduction in momentum and production of force to propel your body in the proper direction. Allowing the muscles to apply force unevenly and multidirectionally will result in a loss of force in your desired direction, which will cause you to be slower. The neutralizers of your knee also prevent your knee from moving in an unsafe direction and limit your risk of knee injury during the high-impact cut.