Without variable valve timing or variable valve lift, the valve timing must be the same for all engine speeds and conditions, therefore compromises are necessary. An engine equipped with a variable valve timing actuation system is freed from this constraint, allowing performance to be improved over the engine operating range.
A variety of medical specialists treat people with osteoporosis, including internists, gynecologists, family doctors, endocrinologists, rheumatologists, physiatrists, orthopaedists, and geriatricians. There are a number of ways to find a doctor who treats osteoporosis patients. If you have a primary care or family doctor, discuss your concerns with him or her. Your doctor may treat the disease or be able to refer you to an osteoporosis specialist.
A doctor of osteopathic medicine (DO) may specialize in pediatrics or surgery. A DO may practice any field of medicine, including pediatrics. A DO may evaluate a patient's stress level and determine what effect it is having on that person's health. A doctor of osteopathic medicine may sometimes practice manipulation of the spine, which is similar to work done by chiropractors. A DO usually uses a holistic approach to treating patients. Doctors of osteopathic medicine tend to spend more time with patients.