Only rheumatologist or orthopedic answer. some hypermobile joints from activites, some born with? can these loose joints make normal joints loose?

No: Laxity or 'loose - jointedness' is generally inherited in a multifactorial fashion.Trauma can 'cause ' loose joints ( shoulder, knee mostly); but 'mild' injury will not cause 'loose joints' in non- lax individuals(if that makes sense). Almost all loose- jointed people are born that way; instability occurs w/ sports and mild injury(shoulder esp.)in 'loose- jointed people' thumb>forearm distance min.

No: "loose joints" are typically genetic, rarely post trauma and never a result of other joints being loose. Most commonly shoulders knees and fingers are affected.