Hello.i wanted ask about my mother.she had a muscle injury in left shoulder, a year back. it pains a lot during seasonal changes.can u help why is it?

Osteoarthritis : She could develop oseoarthritis with the original injury/trauma starting the often progressive inflammitory process. The weather change - flare ups are usually caused by a change (relative change) in the ambient barometric pressure. These pressure changes are often seen with weather changes. Should be followed by a physician and may be helped with antiinflammitory medicine if tolerated.