In the early 20^th Century, physical therapy got its start, and the first professional organization was called the American Women's Physical Therapeutic Association.  In today's time, the organization is called the American Physical Therapy Association.
Physical therapy (outside of the United States known as physiotherapy) treats a wide variety of musculoskeletal injuries, disorders, and pain.  From a person with back pain or neck pain to the most elite athlete can have to endure the treatments.  Even those with simple arthritis in the wrist or knees can undergo physical therapy treatment in order to recover their full movement with less pain.
What is being in the physical therapy profession actually like?  Physical therapists are trained health care providers specializing in movement and movement dysfunction who help patients strengthen physical abilities and relieve pain through the use of therapeutic exercise, heat, cold, and electric stimulation.  Therapists can specialize in a certain field, but most physical therapists today are generalists, assessing and treating a wide range of patients and problems.  Not only do physical therapists treat injuries, they also try to prevent injury by teaching the importance of exercise and nutrition.
"I like working with people," says Joseph Stoudt, MSPT, "which was why I came into physical therapy."
Physical therapists may not be dealing with medicine twenty-four seven, but they provide expertise in human mobility, analyzing gait patterns, prescribing treatment, and recommending devices (such as braces and crutches) to enable clients to move independently.

If you would choose to exercise an injured joint unsupervised, there are several key points to keep in mind.

• Any pain associated with a specific exercise is counter-productive to your rehabilitation and must be discontinued or modified.
  
• Swelling after exercising indicates excessive resistance or inappropriate technique.  Your program must be modified if this occurs.  Ice and a compression wrap should be applied.
  
• Re-injuries occurring during the rehabilitation process may limit your progress.  Episodes of recurring pain will require lowering your resistance and possible sets/repetitions.
  
• Most of the exercises that do not involve knee motion (i.e. hip exercises that strengthen the quads and hamstrings through a process called irradiation) can be done when there is knee pain and swelling as long as no pain is present with the exercise.
  
• When in doubt regarding how much weight to do, always use less weight.  Heave resistance can create high compressive loads in the joint that will wear down the surface.
  

One of the most common injuries that physical therapists deal with daily is injuries involving the knee.  Rehabilitation of the knee can be a long and often frustrating experience.  Atrophy and severe weakness after injury/surgery can be devastating.  Rebuilding muscles can take months in many cases, but must be restored through regular exercise for full join function.  Some basic exercises include, but are not limited to:
Quadriceps sets - tighten muscle on top of thigh by pushing knees down into floor or table.
Straight leg raises - bend opposite knee so that foot rests flat on the surface.  Keeping operated knee straight, lift the leg up.  *Be sure no the raise operated leg higher that the other leg, and repeat.
Heel slides - While lying on back, slide heel toward buttocks, bending knee as much as possible.  To gain additional range of motion use a large towel or gathered sheet that is wrapped around ankle and foot and pull toward buttocks.