Why do some muscles tire more when you’re in a bad posture?

Osteo for Families • January 31, 2023

Why do some muscles tire more when you’re in a bad posture?

Posture is something that comes up a lot.


It is important to understand how your posture can contribute to your aches and pains and if there are ways we can reduce that contribution. 


The muscles in our body all have different functions, some muscles are meant to repeatedly contract such as your heart to pump blood around your body, others are there to help create movement and others to help stabilise our bodies.


These different types of muscles have a different structure and therefore have their own strengths and weaknesses. 

The fibres in our muscles can be classified as slow twitch, usually found in deep postural muscles and help maintain positions or fast twitch which are used for creating movement.


The slow twitch fibres are able to maintain positions for a long time as they use low energy and take a long time to fatigue. However, when we have poor posture we use more of the muscles with fast twitch fibres in them, these fibres tire quickly and we feel muscle fatigue.


Greater use of the fast twitch fibres leads to disuse and weakening of slow twitch fibres leading to greater reliance on fast twitch muscles. This results in greater fatigue and less feedback to your brain about your body’s position.

What can you do to improve your posture?


Change your posture regularly 

Reverse the posture you have been in for a long period. eg slumped forward at a desk – stretch backwards

 Regular exercise and stretching to improve muscle flexibility and strength

 Avoid standing on one leg for a long period of time

 Cross your legs at your ankles and not your knees

 Make sure your mattress and pillow are supporting your body

Make sure your work set up is supporting and encouraging good postures

Get some advice form a health professional, you can call one here… 0416 161 411


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Dr Mariella Berry (Osteopath)

BSC (Osteopathy), MHSc (Osteopathy)

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