Could you comment on this sentence please?

Hi,

Could you comment on this sentence please?

"They believe that in musculoskeletal disorders, a predictable pattern of muscle weakness and shortness happens in the neck and shoulder region in patients with chronic neck pain; and although the degree and severity of muscle weakness and shortness differs in different individuals, their patterns and causes rarely differ.

I want the underlined pronoun to refer to "weakness and shortness". Does it?

Thanks!