PGA Professional Mark Crossfield explains that a chicken wing lead-arm collapse is usually a reaction to a weak grip and poor clubface control. By adjusting lead-hand grip placement to show 2-3 knuckles and using targeted forearm folding drills, golfers can naturally fix their follow-through without forcing lead-arm extension.
A chicken wing in the follow-through is usually a functional compensation to square an open clubface caused by a weak grip.
Forcing the lead arm straight without fixing clubface control will typically result in severe pushes or slices.
Ensure your lead-hand grip shows 2 to 3 knuckles at address, running diagonally across the fingers into the base of the palm.
Practice forearm crossover and elbow folding using the Right Angle and Split Hand drills to develop proper release feel.