Sudden sharp pain in neck followed by pins and needles in arm. felt like an elastic band had snapped. neck still feels tender and had a few twinges?

See a PMR or ortho: Nerves from the neck travel to the arms, and stretching or pinching these nerves often produce these symptoms. Muscle spasm can arise from malposition of cervical vertebra, rapid stretch, or trauma, causing further symptoms. Pillows make a huge difference in providing support for the head over neck. EMG studies can tell if a pinch is present.