Sitting knee extension is relevant when a flexed spine position provokes symptoms, such as in people whose backs complain when they slouch or stay seated too long.
The exercise teaches flexion control in a simple seated position before the same pattern is asked for in more demanding tasks.
What this involves
- Holding the low back still while the leg moves
- Noticing the slump. Most people who fail this have no idea their back moved
- Sit tall on a bench or a firm chair, feet hanging free, with the normal inward curve of your low back restored rather than slumped
How much
Straighten the knee while sitting tall, and only progress if the pelvis stays steady.
Demo video
Further reading
- https://creativecommons.org/licenses/by/2.0/
- https://doi.org/10.1016/j.math.2015.02.005
- https://doi.org/10.1186/1471-2474-8-90
- https://doi.org/10.1186/1471-2474-9-170
- https://doi.org/10.1186/1758-2555-2-11
Safety note
Stop and contact us straight away if you get new weakness in the leg, numbness around the saddle or genitals, or any loss of bladder or bowel control. Those are red flags and they need same-day medical assessment, not exercise
This is educational information to help people understand their options; it is not a substitute for a proper healthcare assessment. An accurate diagnosis is required for effective treatment. If pain or symptoms are ongoing, the worst thing you can do is nothing — seek professional counsel and assessment rather than self-treating indefinitely from a blog post.
This content is educational and does not replace individual clinical assessment.