Neck pain covers the area between skull and upper thoracic, it may also involve neuopathic pain & symptoms.

Shoulder is a shallow ball and socket joint, it provides good flexibility but vulnerable to instability.

Sciatica could only be regarded as symptoms, not as a disease. Various reasons can cause sciatica, it includes piriformis syndrome, disc herniation...  

Wrist and hand are very complicated organ with delicate and complex joints, different ligament, muscle and nerve. 

Elbow joint has static bony structure, and able to fulfil precise and skilful target with delicate muscle groups.

Low back refer to lumbar region below rib cages, and pelvic region between two hip joints, can also be neuropathic pain.

Knee pain originates from knee-cap, MCL , ACL and torn meniscus, baker's cyst and crepitus always also present.

Sprained ankle is the main pain of ankle injury, while bunion and plantar fasciitis are main sources of chronic pain.