I HAVE HAD [PARKINSONS FOR ABOUT 5 YRS. ABOUT EVERY 9 MONTHS I HAVE SEVERE TIGHTNESS AND ACHES IN THE DIAMOND SHAPED MUSCLE BETWEEN MY SHOULDERS FOR 5-7 DAYS. THEN IT SEEMS TO GO AWAY, THANK GOD! I FIND THAT MOTRIN HELPS SOME BUT THE GREATEST RELIEF COMES FROM A BUG SHAPED VIBRATOR I BOUGHT FOR $12 . IT LOOKS LIKE A LADY BUG WITH FOUR LEGS AND IT VIBRATES LIKE CRAZY. IT REALLY RELAXES THAT MUSCLE. IT ALSO SEEMS TO ME THAT STRESS PLAYS A PART IN THE ONSET. GOOD LUCK!