Flexibility, elasticity, extensibility?
Stretching: what does it change?
A fact: after a single stretching session, a short-term (3- to 8-week) or long-term stretching program, our body is more flexible/extensible. A simple question: why do we get more flexible? What body parts/tissues are affected by stretching?
Surprisingly, but not that much, even such a naive question lacks a clear scientific answer. Of course, there are multiple theories trying to answer it. Most of them are based on one or both of these hypothesis:
- as a consequence of stretching, the length of the target muscles increases
- as a consequence of stretching, our sensations when doing a given movement are changed so that it becomes easier.
The first hypothesis is the most easily testable. Studies showed that muscle length does increase during stretching (due to the elastic properties of muscle), but the increase is transient. Testing the change in sensation independent of other changes is basically impossible at the moment.
So, no answer to the how/why questions, only to the what: when we do streching, our extensibility is increased. This means that we cannot really evaluate a priori what is the best way of stretching: the only criterion we have is what works best. For example, it is hard do answer questions like “Is it better do stretch before or after training?” or “Is it better to do multiple short stretches or a single long one?”. Whoever advocates for one option over the other based on human biology is probably just bullshitting.
Stretching exercise: general characteristics
We can describe a stretching exercise using the following parameters:
- Alignment
- Stabilization
- Intensity
- Duration
- Speed
- Frequency
- Mode of stretch
Stretching exercises
- Elephant walk (20/30 reps per leg)
- Single leg LDR
- Grab your feet standing/seated (30 secs)
Lower Back
If you have back pain, stretching can help, but the best remedy seems to be strengthening your muscles. I say this based only on this work though.
- Child’s Pose (hold for 60 secs)
- Knee-to-chest (30/60 secs per leg)
- Seated spinal twist (30/60 secs per side)
- Cat-Cow (repeat for 1/2 minutes)
References
- https://www.physio-pedia.com/Stretching
- Weppler, C. H., & Magnusson, S. P. (2010). Increasing muscle extensibility: a matter of increasing length or modifying sensation?. Physical therapy, 90(3), 438-449.