• SportsWise Physiotherapy

How Does Stretching Work?

Everyone's done stretching before. But what exactly does stretching do and how does it do it? And how should you be stretching, when should you be stretching and should you be stretching? This post should clear up some of the confusion about what stretching does and how you should do it.

Stretching has a few different effects, and depending on what effect/s you're going for the particular stretch, the time you how the stretch and how often you perform the stretch may vary.

The effects of stretching are:

  • Pain relief

  • Increased blood flow

  • Lengthening of the units that make up the muscle

  • Reducing perceived muscle tightness

  • Improving ROM and posture

  • Reducing neural spasticity

How does stretching do all that? Let's go through them one by one.

Pain Relief

Stretching can relieve pain, largely through the other effects it has. Sometimes stretches can relieve pain by taking you out of a painful position. For example, if your back hurts because you've been on your feet all day (lumbar extension) then a stretch that takes your back into flexion will help to relieve your pain.

Increased Blood Flow

When muscles are being stretched, the blood vessels supplying the muscle are more open, allowing more blood to flow through. A good deal of the benefit of stretching before exercise comes from the increased blood flow to muscles a 10-15 second stretch provides.


Muscles are made up of small units called sarcomeres. Holding a stretch for 30-45 seconds at a time actually results in lengthening the muscle by causing a small amount of lengthening to each of sarcomeres which make up the muscle.

Reduced Tightness

"Tightness" as a sensation can be seperate to an actual lack of muscle length. Other than lengthening the muscle, stretching can help reduce a sensation of muscle tightness by increasing blood flow, and also by resetting the nervous system to no longer feel like that muscle is tight.

ROM and Posture

Tight or shortened muscles can impede how far a joint can move and can pull you into suboptimal postures. your hamstrings. for example, when tight can reduce how easily you can straighten your knee, and they can also make you more prone to slouching when sitting.


Spasticity is an issue for people with injuries to the central nervous system such as cerebral palsy, head injuries, spinal cord injuries or strokes. These injuries can lead to increased resting tone in certain muscles. Your 10-45 second stretches won't have much impact on spasticity and sustained positions that stretch the affected muscle/s are required.

If you think tight or short muscles are a problem for you, our physios would be happy to set you up with some stretches, as well as provide any other treatments you may require.

#Rehab #Stretching