Left shoulder blade pain 1 week up into lower neck.turning neck to the left is also limited.no specific injury i can remember. what could cause this?

Muscle strain: This is likely a paraspinal muscle strain or a paraspinal ligament strain. These can often be triggered by some unnoticeable event (sleeping in an awkward position, lifting and object, twisting abnormally) where a muscle and/or ligament is stressed, causing inflammation and pain. Recommend rest, ice/heat, anti-inflammatories, and light activity. Symptoms should improve over 10-14 days.

Disc compression: Mist likely you have compression of your cervical disc. Your doctor can get imaging study like X-ray or MRI to make a diagnosis. In most cases physical therapy would help relieve pain. Surgery is rarely indicated only in complicated cases. Good luck