What is Knee Osteoarthritis?
Osteoarthritis (OA) is a common rheumatic disease, it mostly affects synovial joints such the knee, hip, and hands. Knee OA has a high prevalence amongst older people, affecting up to 30% of people worldwide (Busija 2010).
People who have OA often describe a deep ache and stiffness deep in the knee after prolonged rest. As the disease progresses symptoms often become more persistent and may occur at rest and during the night.
Those with advanced OA often experience the crepitus or ‘creaking’ in the joint along with progressive loss of joint movement. This progressive pain and loss of movement results in increased loss of function particularly during everyday tasks such as walking, climbing stairs, and house work. Knee OA is a leading cause of disability in those over the age of 50. (van Dijk 2006).
Are you at risk of developing knee OA?
Here is a list of the biggest risk factors for the development of pain and disability in people with knee OA: (Silverwood 2015)
- Overweight (BMI)
- Female gender
- Previous knee injury (e.g. fracture, traumatic injury, of surgery)
The above mentioned risk factors are warning signs to help both the clinician and the patient understand who is at risk of developing knee OA and therefore who needs help to reduce their risk.
What are some of the best ways to help decrease the risk of developing OA?
As mentioned above, the one modifiable risk factor for the development and progression of OA is bodyweight. Therefore, the best way to reduce your risk of osteoarthritis is to ensure that you are maintaining a healthy weight for your age and gender.
This can be achieved by making a conscious effort to maintain healthy lifestyle and diet choices, with regular physical activity of at least 30 minutes per day.
What can you do once you have OA?
Currently there is no cure for OA, however exercise in particular strengthening and cardio exercise can help improve the disease related factors that lead to pain and impaired function associated with this disease.
Why are Strengthening and Cardio Exercises so good for knee OA?
The reason why strengthening exercises are so important is because by strengthening the muscles around the joint you are effectively reducing the load going through the joint itself, therefore reducing pain, and improving function (Bennell 2008; Dekker 2013).
You particularly want to target the muscles around the knee joint (e.g. quads, hamstrings, calves, and glutes), to get the best results.
Cardio training (e.g. walking, cycling) helps to increase the peak oxygen uptake of your muscles.
So why is this helpful you might ask? Well by increasing your muscles oxygen capacity,
essentially you are running a more efficient motor (muscle) and therefore are going to expend less fuel for a given task.
For example, activities daily living that were previously painful and difficult due to your OA, can now be achieved with less effort. Thus, by improving your fitness you are able to perform daily tasks easier with less pain, which will result in an overall improvement in quality of life.
Busija L, Bridgett L, Williams S, Osborne R, Buchbinder R, March L, et al. Burden of musculoskeletal conditions: osteoarthritis. Best Practice & Research Clinical Rheumatology 2010;24:757‐69.
Dijk GM, Dekker J, Vennhof C, Ende CH. Course of functional status and pain in osteoarthritis of the hip or knee: a systematic review of the literature. Arthritis & Rheumatology 2006;55:779‐85.
Silverwood V, Blagojevic-Bucknall M, Jinks C, Jordan JL, Protheroe J, Jordan KP. Current evidence on risk factors for knee osteoarthritis in older adults: a systematic review and meta-analysis. Osteoarthritis and cartilage. 2015 Apr 1;23(4):507-15.
Bennell KL, Hunt MA, Wrigley TV, Lim BW, Hinman RS. Role of muscle in the genesis and management of knee osteoarthritis. Rheumatic Disease Clinics of North America 2008;34:731‐54.
Dekker J. Exercise and Physical Functioning in Osteoarthritis; Medical, Neuromuscular and Behavioral Perspectives. Berlin: Springer‐Verlag, 2013.