Protect Knees: Weak Quad Muscles Risk Cartilage Damage

Doctors have known for many years that having weak
quad muscles (in the front of your upper legs) increases risk for
damage to the cartilage in your knees. A study from Purdue
University shows that strengthening these muscles slows down
knee cartilage damage and may even improve knee function
(Arthritis & Rheumatism, October 2006).
The researchers placed 221 adults in their sixties and
seventies either on a program of strengthening their muscles in
their upper legs or just moving their knees in a series of range-of-
motion exercises. The subjects exercised three times per week
(twice at a fitness facility and once at home) for 12 weeks. This
program was followed by a transition to home-based exercise for
12 months. Older people weaken naturally with aging, but the
range of motion exercisers lost more strength than those who
exercised against progressive resistance. The strength training
helped retain joint space, signifying that this group had less loss of
cartilage.
The knee is like two sticks held together by four bands
called ligaments. Strength training stabilizes the muscles that
support the knee and helps to prevent loss of cartilage with aging.
People with knee pain should get a diagnosis from their doctors.
Most will be advised to do exercises that strengthen the knee,
such as pedaling a bicycle or performing knee strengthening
exercises that involve bending and straightening the knees
against resistance. People with knee pain should avoid exercises
that jar the joints, such as jumping or running. More: Why arthroscopic knee surgery is usually useless