A 60-year-old retired seamstress comes to the office reporting decreased sensation in her hands and feet. She states that she began to have the problems in her feet 1 year ago but now it has started in her hands also. She also complains of some weakness in her grip. She has had no recent illnesses or injuries. Her past medical history consists of having type 2 diabetes for 20 years. She now takes insulin and oral medications for her diabetes. She has been married for 40 years. She has two healthy children. Her mother has Alzheimer's disease and coronary artery disease. Her father died of a stroke and also had diabetes. She denies any tobacco, alcohol, or drug use. On examination she has decreased deep tendon reflexes in the patellar and Achilles tendons. She has decreased sensation of fine touch, pressure, and vibration on both feet. She has decreased two-point discrimination on her hands. Her grip strength and her plantar and dorsiflexion strength are decreased. Where is the disorder of the peripheral nervous system in this client