Why sitting makes joints feel stiff
Joints are built for movement. Staying in one position for a long time is experienced by many people as stiffness that eases after the first steps. In office work it is one of the most common observations of all.
This start-up stiffness is not in itself a sign of disease. It deserves attention when it increases noticeably, lasts a long time, or is accompanied by swelling and redness.
Frequency beats duration
For the musculoskeletal system it is better to move briefly every hour than at length once a day. Two minutes of standing, a few steps, and fully straightening and bending the knees once are enough for the purpose.
The most common mistake is saving movement up and catching up in one long session at the weekend. Distributed, light load is the better stimulus for joints.
Practical workplace adjustments
What helps is whatever makes position changes easier: a seat height where the feet rest flat, a screen at eye level, standing occasionally during calls, and deliberately placing the printer or water further away.
A height-adjustable desk helps but is not decisive. What is decisive is alternating between positions, not the single perfect position.
When this becomes a medical question
If morning stiffness lasts considerably longer than half an hour, if several joints are symmetrically affected, or if swelling, redness, fever or night pain appear, it needs clarifying.
In those cases early assessment matters more than any self-help measure, and a supplement is not a suitable first step.