Reading joint feedback
Golf tracks the major joints frame by frame through the swing — hips, shoulders, elbows, wrists, and knees — and compares the timing of each against an expert reference of the same club and shot type.
A flagged joint means its timing diverges from the reference at a specific point in the sequence, not that the joint itself is somehow wrong. Everything downstream of that joint tends to compensate for it, which is why a single flagged joint often explains several visible symptoms at once — an early hip extension, for instance, can show up as a steep plane, a thin strike, and a blocked follow-through.
Work on the earliest flagged joint in the sequence first. Fixing a root-cause joint frequently resolves later, downstream flags without needing to address them directly.