Exercise as it relates to Disease/Exercise and Juvenile Idiopathic Arthritis

Brief Background
Juvenile Idiopathic Arthritis (JIA) is a chronic autoimmune inflammatory joint disease that affects one or more joints and persists for six or more weeks. It is the most common form of arthritis in children and adolescents, and can occur from the age of birth up to 16. The most common onset ages are between 1 and 3 years of age. It is characterized by persistent joint inflammation, resulting in swelling, pain and a limitation in movement. There are seven subtypes of JIA, however, the most common subtype is oligoarticular; which affects four or fewer joints and accounts for approximately 30 per cent of JIA. The exact causes of JIA are still unknown. However, it is believed to be due to a combination of genetics and environmental factors, such as viral infections, that trigger the arthritis in genetically predisposed individuals [4]. There is currently no cure for JIA, yet a range of treatments can be administered to reduce pain and minimise the loss of function. These treatments include pharmacological interventions, nutritional therapies, thermotherapies and exercise interventions.

Explanation of the Issue
The most common symptoms of JIA include joint swelling, pain and stiffness, resulting in limited movement of affected joints. Other symptoms may also be limping, fever, rash, excessive clumsiness and swelling of the lymph nodes. Symptoms will vary depending on the individual and may lead to reduced physical activity in affected persons, resulting in deconditioning and functional deterioration, as well as other health problems caused by an inactive lifestyle [1]. Therefore, early detection of JIA is critical to ensure prompt treatment and to prevent long-term complications that may result not only from the arthritis but also from the possible physical decline that follows.

JIA has an early onset age; consequently the physical impairments can have a range of flow on effects throughout life. For example, children with JIA are at an increased risk of developing osteoporosis and oesteopenia as a result of their reluctance to move and put weight on affected joints. If a child’s mobility is compromised it not only affects their health, but also their ability to participate in activities, such as team sports and school activities. Active children are at reduced risk of obesity, have increased cardiovascular fitness, and tend to sleep better. In the past it was believed that exercise had detrimental effects on children with JIA. However, recent studies have now shown that exercise does not exacerbate the symptoms of arthritis, and can actually be used as a form of treatment [1].

Recommendations: Exercise Interventions
Exercise is recommended for treatment of JIA as it helps to keep joints mobile and maintains muscle and bone strength. Children suffering from arthritis have been shown to be physically less active, with reduced aerobic fitness compared to healthy children [2]. Therefore, exercise is not only important in treating the acute symptoms of JIA, but also in improving health and delaying mortality from other chronic diseases.

Studies on the effects of physical activity on the musculoskeletal and cardio-respiratory status of individuals with JIA indicate that both aquatic and land base exercises can be beneficial. Thus, exercise recommendations often include a mixture of different types of exercise in order to achieve maximal benefits for the patient. It has also been shown that individualized training programs are the most beneficial [7].

Aquatic Exercise
Aquatic exercise is often recommended for children with JIA as the buoyancy of the water places less stress on the affected joints. This is turn allows for increases in their range of motion (ROM) and mobility without increases in pain or damage to inflamed joints (5). Aquatic exercise can be used to improve a child’s aerobic fitness, resulting in improved cardiovascular function. They have also been shown to be effective in improving muscular strength in children with JIA and may help reduce the risk of obesity and other disease states associated with being inactive [4][7].

Strengthening Exercise
Studies have shown that strength training does not exacerbate the symptoms of JIA. While aquatic exercises may sometimes be recommended over weight-bearing exercises due to the reduced stress placed on the joints, research has indicated that arthritis in children may result in significant muscular deficits. Weight-bearing exercises are also a significant determinant of bone width and density in children with JIA [7]. Therefore, weight-bearing exercises should be an integral part of an exercise program for JIA patients. Strength exercises may result in increases in muscular strength, muscular endurance and bone strength, all resulting in improved functionality of the joint. Stronger muscles may also help support joints that are weak. There are also long term benefits of strengthening exercises, particularly for those who go on to suffer from osteopenia or osteoporosis as a result of JIA [6]. Two types of strengthening exercises should be considered:

Isometric exercises: which can be beneficial during acute flare-ups as they strengthen the muscle without moving the joint. Therefore, resulting in reduced pain while maintaining muscle strength and function [6][8].

Isotonic exercises: move the joint through bent and straight positions and therefore should be done predominantly when arthritis is less active. Isotonic exercises can be done with or without weights to improve muscle strength and joint range of motion [6].

Aerobic Exercise
When the arthritis is less active, children should be encouraged to maintain their aerobic fitness through aquatic exercises (as mentioned earlier), as well as low-impact aerobic activities, such as walking and bicycling [6]. Children should also be encouraged to participate in sporting and recreational activities with other children. This will help maintain their cardiovascular fitness and may have a range of positive psychological and social flow on effects for the child.

Stretching
Stretching should be incorporated into the exercise program as it maintains the normal range of motion of a joint by moving it through bent and straight positions without working the muscles against resistance or weights [6]. Stretching should be done even when a patient is suffering from acute inflammation and pain, as it is essential to prevent joint contractures, resulting in permanent damage to the muscle [2].