As mentioned above, many spoken dialects have a process of emphasis spreading, where the "emphasis" (pharyngealization) of emphatic consonants spreads forward and back through adjacent syllables, pharyngealizing all nearby consonants and triggering the back allophone  in all nearby low vowels.
It's worth noting that many spoken dialects exhibit a phenomenon where emphasis is transmitted to surrounding syllables, causing the "emphasis" (pharyngealization) of emphatic consonants to propagate forward and backward through adjacent units, ultimately affecting nearby consonants and triggering the back allophone in low vowels.