Why do the simplest movements become painful as osteoarthritis progresses?
When we think of knee osteoarthritis, we often imagine the "natural" wear and tear of cartilage due to age. However, it is the everyday gestures — walking, climbing stairs, getting up from a chair — which put the most strain on the knee and which, over time, accelerate the progression of osteoarthritis.
To understand why the joint becomes painful, it's necessary to analyze what the knee actually undergoes with each movement: pressure, shear forces, load imbalances, and repetitive microtrauma. Far from being insignificant, these stresses determine the progression of the disease and explain why some patients experience faster osteoarthritis.
Walking: a simple movement, but with considerable forces.
Walking seems to be the most natural activity. Yet, each step applies a load to the knee equivalent to 2 to 3 times body weight.
In a 70 kg patient, this represents more than 200 kg transmitted in the joint with each step.
In a knee that is not very worn, these forces are easily absorbed.
But in the case of osteoarthritis:
- The cartilage loses its elasticity.
- the surfaces become irregular,
- lubrication decreases,
which makes walking much more aggressive for internal structures.
The more the distance, cadence or speed increases, the more the joint load accumulates and accelerates wear and tear.
Stairs: one of the most demanding activities for the knee
Going up or down stairs is one of the most demanding movements for the joint.
Uphill
The applied force reaches 4 to 6 times body weightbecause the knee must support the body while propelling upwards.
Downhill
It's even more demanding: the descent causes the quadriceps to brake, generating strong forces of shear, particularly painful in cases of wear and tear of the femoropatellar compartment.
For an arthritic knee, these repeated stresses:
- promote inflammatory flare-ups.
- irritate areas that have already been thinned,
- put excessive stress on the damaged cartilage,
Everyday postures: squatting, sitting, twisting
Certain positions or movements, often overlooked, cause significant mechanical stresses:
Squat or kneel
These movements compress the cartilage to the maximum, especially at the femoropatellar level.
Prolonged pressure in these positions can increase pain and accelerate deterioration.
Getting up from a chair
This action increases the pressure on the joint, especially if the chair is low.
The knee must exert intense effort to generate the vertical thrust.
Rapid twists and pivots
Rotational movements apply shear forces to weakened cartilaginous surfaces.
It is often during these movements that the "creaking" sounds appear.
Why do these activities accelerate osteoarthritis?
Cartilage wear is not just a matter of age:
it depends mainly on the quality of movements and mechanical forces applied to the knee.
When the stresses exceed what the cartilage can absorb:
- the micro-cracks widen,
- the surface becomes rougher,
- friction increases,
- inflammation sets in more easily.
This vicious cycle explains why some patients see their osteoarthritis progress rapidly, even without engaging in intensive sport.
Is it possible to continue walking or climbing stairs despite having arthritis?
Yes — but with adaptations. An arthritic knee does not like fast paces, long descents, inclined surfaces and prolonged flexed postures.
On the other hand, it tolerates better: gentle and intermittent walking, flat surfaces, the use of a handrail on stairs and well-aligned resting postures.
It's not the movement itself that damages the knee: it's intensity, the repetition and the poor distribution of burdens.
How can you best protect your knee on a daily basis?
Without repeating the solutions from the existing article, here are some new strategies aimed at... mechanical loads :
- Easing the descents : alternate with the elevator during painful moments.
- Adjust the pace : brisk walking puts more strain on the cartilage.
- Choose cushioned shoes to reduce the impacts.
- Avoid deep bends which compress the knee at more than 90°.
- Opt for soft surfaces outdoors.
- Strengthen the stabilizing muscles to reduce lateral stress.
These adjustments allow you to protect the joint without giving up an active life.
Conclusion
Knee osteoarthritis is not just wear and tear due to time: it is strongly influenced by the mechanical loads applied on a daily basis.
Walking, climbing stairs or simply getting up from a chair can, depending on the condition of the joint, accelerate cartilage degradation.
Understanding these mechanisms allows for adapting movements, protecting the knee, and preserving mobility in the long term. Personalized care helps each patient learn how to move without worsening the wear and tear and how to better distribute the daily workload.
