What a compensation pattern is
When a joint cannot produce the range or control a movement requires, the nervous system finds the motion elsewhere. A squat blocked by stiff ankles may show the heels lifting or the low back rounding; a press limited by tight thoracic extension may show the lumbar spine arching to fake the overhead position. The task still gets completed, but the load is redistributed to tissues that did not evolve to absorb it there.
These substitutions are usually unconscious and can persist long after the original restriction appears, because the brain prioritizes completing the task over how it is completed.
Why the borrowed joint pays the price
Repeatedly asking a stability-oriented segment to behave like a mobility joint concentrates stress where the structure is least suited to it. This is associated in the literature with overuse complaints rather than a single dramatic event. It raises risk; it does not guarantee injury, and many factors including load, recovery, and individual tissue tolerance contribute.
Addressing the root, not the symptom
The practical lesson is to restore capacity at the restricted joint rather than only cueing the compensating one. Persistent pain or a movement that will not correct with mobility work warrants assessment by a physiotherapist or qualified coach. This is general educational information, not medical advice.