As this is happening, the young girl is audibly asking him to “please stop,” but she is unable to move because she is being held down. This is downright wrong and an extreme example of someone being forced to do something that she simply can’t. But it’s actually common practice for a lot of trainers to “stretch” their clients after sessions. There’s a ton of issues that I have with something like this being common practice, especially without awareness of an individual’s needs on an case-by-case basis.
Yes, for many people stretching does in fact “feel” good. But are you actually lengthening the muscles and making them longer and leaner? No. An increase in range of motion is mostly attributed to an increased tolerance to stretching.
During stretching, your brain and nervous system send signals to guard yourself from causing harm. The reason that you feel tension during stretches is because you’re putting your muscles in an elongated position. This elicits a threat response that basically tells you when you should stop stretching. The cause for this threat response can be incredibly complex; injury history, alignment & position, and a lack of stability elsewhere in the body can all come into play. The only way you can really “lengthen” a muscle is via eccentric contractions.
People who are crazy flexible (or hypermobile) have likely been practicing for years. Cheerleaders, gymnasts, and dancers have tons and tons of flexibility primarily because of changes that occur at their joints when they started at a very young age. Everyone should theoretically be able to perform a split since the hip joint allows for 170 degrees of flexion. But the good ole’ “use it or lose it” mantra applies here. If it’s not a range of motion that is practiced on a regular basis, you’ll have a hard time going further when your nervous system hits the brakes because it feels unsafe.
It is absurd to force someone into a stretch, and it should never be done. It can result in strains or even tissue tears where the force is being applied. If it feels good to stretch after a session, go ahead, but make sure it feels gentle. Breathe and try to relax into those elongated positions, which will help increase your tolerance to stretch.
Finally, stretching will not prevent injuries from occurring. To prevent injuries you must be both mobile and have full control over the range of motion you posses. You have to be strong across all of your movement capabilities. This is trained through multi-planar, loaded movement and targeted contractions while your muscles are at their end ranges (fully lengthened or shortened). It will not happen while some trainer stretches you and forces you into a split.