Maximal Resistance
Assisted stretching allows for what cannot be obtained through self stretching: maximal eccentric force. As you progress in your resistance flexibility and strength training, you will eventually need to use maximal force during the eccentric/negative/elongation phase of movement in order to achieve maximal results.
It takes at least twice as much force to resistance stretch a muscle as it does to strengthen it. So if you strengthen your bicep with 50 pounds, it takes at least 100 pounds of force to resistance stretch it. Areas of the body that house accumulated dense fascia and scar tissue may have resistance that is up to 10 times greater than the muscular strength! This is where help from another person (or a team of people) becomes an essential part of your training program.
One-on-one assisted stretching provides results far greater than what you can achieve through self stretching. Two-on-one, three-on-one, or four-on-one assisted stretching provides even greater benefits in less time. Being assisted by multiple people allows maximal resistance and tension to be generated, greater stability in all vectors of movement, and more sophisticated movements.
Efficient Distribution of Energy
Self stretching teaches you how to harness muscular tension and fascial resistance through the use of use sub-maximal eccentric force. Partner assisted stretching allows you to generate maximal tension and resistance with the help of another person. This not only provides you with a wonderful stretch but also provides a beneficial workout for you and your assister. Your assisters are strengthened as they stretch you and are stretched as they strengthen you. Your resistance is used efficiently instead of being pumped into a workout machine which stands to gain no benefit from your hard work.
External Perspective
Self stretching allows you to gain an internal perspective on your body and your self while assisted stretching allows another person to offer you the external perspective that you cannot get on your own. Practicing both self stretching and assisted stretching ensures that you cover all of your bases with an internal and external profile of your body and state of being.
All Phases of Movement
For optimal training, all phases of movement must be targeted: concentric, eccentric, and isometric. Concentric training occurs when a muscle shortens while overpowering an outside force. This is traditional strength training and is the foundation of most physical training protocols. Isometric training occurs when a muscle contracts while remaining in a static position. This can be helpful for establishing stability in the maximally shortened position, the maximally elongated position, and at any point in between the two. Eccentric training occurs when a muscle is contracting while an outside force overpowers the muscle, causing it to elongate under a load.
Eccentric training is the missing link in nearly everyone's physical exercise protocol. One reason for the slow adoption of eccentric training is the practical challenges of providing a safe and effective method to explore this phase of movement.
One way to eccentrically train is to focus on the elongation phase of movement during traditional strength training. For example, after performing a bicep curl, you can lower the weight slowly to focus more on the elongation of the muscle. This is a good start, however, a muscle can withstand much more force during the eccentric/lowering phase of movement than it can during the concentric/shortening phase. This is why it's so much easier to lower the weight during strength training than it is to lift it. So maximal force needs to be exerted during the eccentric/elongation phase of movement for optimal benefits.
One way to maximally load the eccentric phase of movement would be to choose an amount of weight that is beyond what you can overpower during a bicep curl, lift the weight with both arms, and once you have completely shortened your biceps, to release with one arm and let the weight elongate your other arm under the increased load. Or you could train both arms simultaneously by having spotters assist you during the shortening phase of movement. This way of training is more dangerous, however, as you are at the mercy of the external force, since it is overpowering you. This is where external force provided by another human is key, as your assister can feel into your body while overpowering your force and stay within your safe and optimal ranges of motion. This not only provides eccentric training, but also safely provides the excessive eccentric loading that is necessary for optimal benefits.
All Vectors of Movement
Aside from needing to excessively load the eccentric phase of movement, it is also vital to do this through very specific movement pathways. Through the assistance of others, you are also able to be resistance flexibility and strength trained in every angle and direction. Most of the self stretches target only one or two vectors at a time. Getting stretched by others allows all three vectors of the proximal joints to be targeted simultaneously: adduction/abduction, flexion/extension, and internal/external rotation. Extra hands also allow the vectors of the distal joints to be targeted which creates an even greater and more comprehensive workout.
Your assister, or multiple assisters, will be able to feel where your pathway of greatest resistance is and move your arm/leg through that pathway for optimal gains in eccentric flexibility. Additionally, your assisters can move you through the pathway of least resistance to concentrically strengthen your weakest pathways.
You and your assisters can zoom in on a particular muscle group and first determine the strength and flexibility of each of these vectors and then provide the proper training required to upgrade that area of your body. Assisted flexibility and strength training provides a level of sophisticated and customized movements for your body that goes beyond traditional exercise equipment and personal training.
Action Specific Training
Partner assisted stretching allows you to balance your asymmetries by first profiling your life activities and experiences to identify your habitual movement patterns. Then you and your assister can resistance stretch the muscles that are constantly overworked and strengthen the muscles that are often ignored. This allows for sport specific training along with training for any other type of activity that requires frequent repetitive movements. The immediate result is a release of tenseness, pain, and stress along with gains in flexibility, strength, posture, health, and mental fitness. The ultimate result is an overall increase in performance.
Assisted Stretching Example
Resistance Flexibility Training
To stretch, begin in position one and activate your hamstrings by continuously kicking your thigh and leg down toward the ground as your partner lifts your leg up.
Resistance Strength Training
To strengthen, begin in position two and activate your hamstrings by continuously kicking your thigh and leg down toward the ground as your partner slows you down.