"Unstable conditions" refers to situations or circumstances that are unpredictable, changeable, or uncertain. It implies a lack of stability or security in a particular environment or situation. Full definition
These changes lead to a more efficient pattern of muscular contractions in that specific, dynamic movement under unstable conditions, which improves strength very substantially, in a stability - specific way. (strengthandconditioningresearch.com)
While most scientists believe Larsen C's breakdown was largely natural, climate change is creating unstable conditions across Antarctica. (earther.com)