Final answer:
Cutting the oblique pulley of the thumb would most likely result in a loss of grip and some strength, but would not completely immobilize the thumb. The thumb's mobility is significant for gripping actions facilitated by its complex musculoskeletal structure.
Step-by-step explanation:
If the oblique pulley of the thumb is cut, the thumb would likely lose its grip and potentially some strength. The oblique pulley is important for the functioning of the thumb, which plays a critical role in opposition—the movement that brings the tip of the thumb in contact with the tips of the other fingers to grasp and hold objects. However, a cut oblique pulley doesn't necessarily render the thumb immobile or fully non-functional; fingers can still extend and retract to some extent, and other muscles and pulleys may compensate to allow some movement.
The first metacarpal bone provides the thumb with significant mobility independent of the other metacarpal bones. This is vital for the thumb's gripping action, which is partly facilitated by the mechanism of the oblique pulley. Such an injury might necessitate medical intervention, such as surgery or physical therapy, to restore the thumb's full functional capacity.