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


-- 

Dr Mariella Berry (Osteopath)

BSC (Osteopathy), MHSc (Osteopathy)

Fab Marchesini: Outdoor group fitness
By Key to Life Health and Fitness February 8, 2026
Congratulations to Fab Marchesina our February Member of the Month. Fab has been a member of Key to Life for over 8 years and has been a regular at the 6am and 6:30pm Box Blast Outdoor Sessions and has in more recent times included regular Body Blitz Sessions in his routine.
Front cover of the Healthy Eating for Adults brochure
By Key to Life Health and Fitness February 7, 2026
The Australian Dietary Guidelines (ADGs) and the Healthy Eating for Adults brochure provide invaluable resources to guide individuals towards healthier eating patterns. Here, we'll explore the value and practical use of these essential tools.
Woman completing a seniors fitness class
By Key to Life Health and Fitness February 7, 2026
Discover the benefits of functional training for senior health. Improve balance, strength, and mobility with tailored fitness programs at Key to Life Health and Fitness.
High Protein Greek Yoghurt Banana Oat Muffins
By Key to Life Health and Fitness February 7, 2026
High Protein Greek Yoghurt Banana Oat Muffins: A delicious and healthy high protein snack.
Four meal prep containers filled with nutritious food
By Key to Life Health and Fitness February 7, 2026
Unlock your fitness potential with the power of nutrition! Fuel your journey, optimize performance, and reach your goals.
Image of driver and view through windscreen
By Osteo for Families December 1, 2025
Whether it’s exploring during the holidays, going for a weekend drive, driving across Australia, visiting family and friends or driving to a holiday resort. We can spend a long time sitting in a car, in a very similar position. So here are some tips on how to take care of your body when spending a long time in the car.
More Posts