Race Comment Explainer

Original comment with matches highlighted:

towards rear, pushed along and struggling 4f out,

Matched phrases & meanings

Phrase	Meaning
Pushed along	The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Towards rear	Running near the back of the field.
tailed off	A definitive statement that the horse was finished and effectively out of the race

Summary

The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Running near the back of the field.
A definitive statement that the horse was finished and effectively out of the race