Walking into a gym, you will find people who may all have different theories on how to gain strength and size. Some may use the full range of motion for exercises, while others may use just half the range of motion. Knowing what exactly range of motion is and how various phases of motion affect your muscles will help you to create a program to fit your goals.
Range Of Motion
Range of motion, or ROM, refers to the amount of movement that your joints, muscles or ligaments can safely go through. Injury can occur when you take your body past the proper range of motion. An example would be straining your lower back after reaching for something placed high above you. When talking about ROM, you may also hear the terms concentric and eccentric. These two terms refer to the motion in any exercise.
The eccentric part of a movement occurs when your muscle is elongated. Most exercises start in the eccentric position, then progress to concentric. When you are performing a biceps curl, you start with your muscles in an eccentric form. During the eccentric part of the exercise, your muscles are capable of producing a greater amount of force as well as muscle growth. It is also in this phase that your risk of injury or soreness will be at its greatest.
The concentric part of your exercise will start when the muscle begins to shorten in length. Using the biceps curl example, once you raise the weight to a 45-degree angle, or halfway up, you will begin to perform the concentric part of the exercise. Unlike the eccentric part of the exercise, there is not a significant amount of force that is produced during this part of the movement.
Combining The Two
Using the full range of motion during your exercise will allow the entire muscle group to be used. This will help to avoid muscle imbalance issues that could result from only using a partial range of motion. If you are looking to add strength, or if there is an area you want to focus on, you will use the eccentric part of the exercise. When performing your exercises, you will either start with one set of eccentric exercises followed by a set using the full range of motion, or vice versa. You can also perform what are known as 21s, this exercise requires you to perform seven repetitions in the eccentric phase, seven in the full range of motion and seven in the concentric phase. If you find that you have hit a plateau or just want to change your program a little, try using the various range of motions in your workout.
- ACSM'S Foundations of Strength Training and Conditioning; Nicholas Ratamess
- Photodisc/Photodisc/Getty Images