Trapezius muscle: What it does and how to keep it healthy

Situated in the neck and upper thorax, a strong trapezius muscle is vital for triathletes wanting to perform at their best. Physio Rachel McCulloch explains why it's important, the best stretches for it and what to do if it starts to hurt

Trapezius stretches

Where is your Trapezius muscle?

The trapezius muscle covers a large area of the neck and back. Starting at the base of the skull it descends down the neck to the middle of the back, and extends laterally to the tips of the shoulder blades.


What does your Trapezius muscle do?

Broadly, the trapezius (traps) has two main functions: stabilising our posture in static positions, and moving us around. It works with other muscles to produce movements for the head, neck, shoulder blades and thorax area (rib cage).

Why is the trapezius muscle important for triathletes and swimmers?

With triathlon being a multi-disciplined sport, the traps really do get worked in a few different ways. During the swim, it works in a mainly rotational manner, allowing us to turn our head when breathing, or as part of the body roll movement required for an efficient glide through the water. The upper trapezius move the shoulder blades enabling the best reach out of every pull.

Once on the bike, the traps serve a mainly postural role, fixing the positions of the thorax, shoulders and head. The muscle thus needs to be strong to cope with the demands of upper body loading required to keep good form. Occasionally, you’ll use the upper traps for head movement; checking your blind spot for the traffic during training rides, or for keeping an eye out for that nemesis you’d like to beat during competition.

As you move into the run, the traps then work to gain that upright posture. They serve to provide a solid frame for the work of your expanding rib cage, and hold up your spine so that your limbs can work efficiently.

What are the best trapezius stretches?

Upper fibers trapezius stretch

  1. Sit or stand in a good, upright posture, with your right arm reaching back and down behind your back.
  2. Drop your head forward onto your chest, tip your head away from the stiff side, and rotate your head toward the stiff side.
  3. Bring your opposite hand up onto the side of your head to assist in the stretch.
  4. Reach further behind your back to increase the stretch if needed.
  5. Return to the starting position and then repeat.

Thread the needle with roller

Sets: 2 Reps: 8 Hold: 3s

1. Start in a plank position with the hands directly under the shoulders and the knees under the hips.
2. Keep your chin tucked in, back straight and shoulders back.
3. With one arm, reach under the other onto the roller, palm up, and roll the arm and shoulder through.
4. Return to the centre and raise the arm up and back to open your chest.
5. Repeat with the other arm if indicated.

What causes pain in trapezius muscle?

The main causes of pain in the trapezius is an overuse injury; mainly asking the muscle to remain shortened or lengthened for prolonged periods. Our muscles love the happy medium of the mid range with regular movement.

In triathletes, the upper traps can become irritated if your upper spine starts to curve forward from many hours on the bike – and maybe from that WFH set up too. In turn, the neck then has to effectively bend backwards to allow us to look ahead and those upper traps are shortened for lengthy periods.

Conversely, the middle and lower traps can spend excessive time in a lengthened position when our back or shoulders are rounded. This makes them less efficient at doing their job when we need to straighten up or rotate,  they consequently then start to weaken over time, fatiguing easily with little exertion – hello DOMS.

How to relieve pain and discomfort in the trapezius muscle

Simple steps work well for the traps and prevention is often better than reactive treatment. Here’s some things to try:

  • Make sure your working posture is well set up – after all, you spend longer here than in any other of your tri disciplines.
  • Double check your bike set up to make sure your handlebars aren’t too close and causing excessive spinal curvature.
  • Use a foam roller or trigger point ball to release tight spots on the back and shoulder area – do not do this on the neck itself.
  • Feel free to add in some upper back strengthening to your weekly strengthening session.
  • If you have persistent pain or symptoms which keep recurring, then seek some help from a physiotherapist.

If you have any health concerns at all or are worried about injuries always consult a doctor, pharmacist or chartered physiotherapist. 


Physio Rachel McCulloch is a consultant rehab physio at Six Physio Parsons Green.