Extension Exercises x 15 times x twice daily - lying on tummy, take left arm up for 3 seconds, then bring it down, right arm up for 3 seconds, bring down. Bring right leg up, hold for 3 seconds, bring it down. Then right leg up and hold for 3 seconds and bring it down. Repeat twice a day- 10 times. Bhujang Asana -- Lie flat on your stomach, keeping the palms out, bend the neck backward, take a deep breath and while holding it for 6 seconds, raise the chest up. Release breath and relax your body. Repeat the exercise 15 times twice daily.

Hi,  it could be a muscle strain,  acute muscle strain s are very painful, do take intravenous or oral pain killer with muscle relaxant,  else it could be prolonging.

Hello, its look like muscular strain.Apply pain relief gel n do hot formatation twice or thrice in a day.