Read the following article and answer the question.

I have n't been in the best mood lately . I think it 's because my lower back has been giving me pain and last night my ankle was hurting quite a bit . Kevin rubbed some ibuprofen gel into it and it helped a lot . On Saturday we did a ton of errands that needed to be done .

What is the connection between ankle and back pain and a lower than normal mood ?
If someone is in pain , they are automatically less likely to be in good spirits as a result