Persistent pain in neck could be due to cervical spondylosis, bad neck posture, muscle weakness. Headache and shoulder pain often occurs when there is neck muscle spasm (in upper trapezius muscle). Shoulder pain could be due to shoulder pathology or due to neck muscle spasm or radiating pain caused by nerve compression at neck. Consult a nearby orthopaedician for thorough examination and diagnosis. If it is cervical spondylitis, shoulder exercises will not help. You need to consult physiotherapist to: 1) strengthen neck muscles (cervical isometric exercises) 2) stretch neck muscles if tight 3) myofascial release if there is muscle spasm 4) postural correction 5) work ergonomics to prevent strain on spine. Treatment for shoulder pain will depend on the diagnosis.