hello mem welcome to HCM i think you are suffering from cervical spondylosis. it means arthritic changes occur due to age and prolonged neck erecting job. this arthritic changes occur in cervical vertebra. cervical arthritis cause friction upon nerve and cause throbbing pain and numbness in upper arm and back and neck. please follow these treatments -do regular exercise of arm, neck and back =do isometric exercise of neck. it will strengthen the muscle of neck and back which eliminate the friction on the nerve -do hot water fomentation at back and neck. it improves circulation as well as removes waste products which produce pain. it increases the nutrition that repairs the damaged part -take ultrasonic waves treatment at physiotherapy clinic. it cause micro massage effect at micro level and repair that. i think this may help this treatment absolutely will relieve your pain thanks