Efficacy of Eccentric Resistance Training in Persons With Knee Osteoarthritis

Arthritis is the leading cause of disability in the United States. Osteoarthritis (OA) is
the most common type of arthritis and affects nearly 27 million Americans. Knee OA is the
most common type of osteoarthritis and is estimated to affect 42.1% of women and 31.2% of
men over the age of 60.

Osteoarthritis is most likely multi-factorial with several underlying causes. It is no
longer considered "a degenerative joint disease" but rather a process that involves dynamic
biomechanical, biochemical, and cellular processes. It not only involves degeneration of the
articular cartilage, but also inflammation of the synovium, changes to the underlying
subchondral bone, and the development of osteophytes. Currently, it appears that numerous
systemic factors can lead to the initiation of OA through different causal pathways . These
systemic causes can then be amplified by local factors such as trauma or increased loading
caused by obesity.

Currently, there is no "cure" for OA and attempts to find a disease modifying drug have been
unsuccessful. Thus, treatment currently focuses on mitigating factors that are known to
affect the radiographic progression of the disease as well as lead to activity limitation
and participation restriction.9,10 Decreases in lower extremity strength are a major cause
of activity limitations given the vital role of strength in activities of daily living.

One method that is used to mitigate progressing factors is through the use of an exercise
program. Many types of exercise have been used successfully in the literature including
resistance training. Resistance training can take many different forms such as isometric,
isotonic (concentric and/or eccentric) or isokinetic with various intensities. Presently,
there is little evidence for the use of eccentric training interventions for patients with
knee OA. This study aims to further examine this type of resistance training for the OA
population. Therefore, the purpose of this study is to examine the effects of low intensity,
long duration eccentric resistance training and high intensity, short duration eccentric
resistance training in individuals with knee OA. Ideally, this study will allow us to
determine the overall effects of eccentric resistance training as well as the potential
differences of the two types of eccentric resistance training.

Inclusion Criteria:

Individuals will be included in the study if they are:

- at least 55 years old,

- cognitively able to understand directions,

- able to ambulate at least 50 feet without stopping,

- are currently experiencing knee pain and

- meet at least 3 out of 6 criteria of the European League Against Rheumatism (EULAR)
criteria for knee osteoarthritis diagnosis.

Exclusion Criteria:

Individuals will be excluded from the study if they have:

- a diagnosed medical condition that would limit physical ability, including acute or
active fractures, myocardial infarctions, stroke,

- a traumatic brain injury within the last 6 months, or

- joint replacement within the last 12 months. Individuals with chronic neurological
disorders limiting motion or present with any known contraindication for balance
training will also be excluded from the study.