Anecdotally, it is reported that individuals with joint pain can predict changes in the weather, in particular the onset of rain, snow, and a drop in barometric pressure. Many clinical studies have been performed to show a relationship between weather and joint pain; however, the results have been inconclusive. This area is being increasingly viewed as an important topic for investigation as a result of suggestions from patients with joint pain and also from physicians. It is thought that if a link between weather and joint pain can be established, this may greatly influence the management of joint pain and provide an avenue for patients to help alleviate their symptoms. It may also have implications for public health. Despite the speculation and the large number of individuals claiming that weather affects their joint pain, the weather sensitivity of joint pain and the mechanisms underlying it remain a mystery.
Knee pain is very common, in fact one of the most common musculoskeletal disorders. It is known to have a great number of causes, one of the most frequent being osteoarthritis, a degenerative joint disease. The ageing of the world population has resulted in a great rise in the incidence of osteoarthritis. This has led to the condition being cited as a cause of “major disability” in the elderly. This rise has meant that not only is osteoarthritis a major problem for western societies, but it is also a rising issue for the developing world. The burden that osteoarthritis places on individuals and the healthcare systems of societies is large and is set to increase greatly. The management of osteoarthritis is a significant issue and there are few effective interventions to halt the progress of the disease. This is of great importance to sufferers of the condition and also the physicians that care for them.
Understanding Weather Sensitivity and Knee Pain
Part II of the paper focuses on the explanation and reasons behind weather sensitivity and its effect on knee pain. It is suggested that since the dawn of medicine, prevailing wisdom has suggested that certain environmental conditions can affect pain symptoms. Joint pain is often considered a specific example. In fact, upwards of 90% of people with bone and joint pain report that their pain is made worse by the weather. Despite these strong beliefs by patients and healthcare providers, the empirical evidence supporting an effect of weather on joint pain is mixed. This is due to a range of methodological challenges associated with weather research and a relative lack of research on the topic. These limitations have combined to create a body of literature that is somewhat anecdotal and, in some cases, conflicting. However, in recent years, a small but growing body of research has begun to examine the extent and nature of the influence of weather on joint pain, and such research is beginning to shed some light on the topic.
Definition of Weather Sensitivity
A more recent study from 2007 investigated 200 people with osteoarthritis for a similar effect. Using a pain calendar over several months and telephone interviews, they matched the pain data from two subsets of patients with meteorological data. This study claimed there was a statistically significant association between pain level and changes in barometric pressure.
This has been investigated in several studies. One such study from 1968 involved assessing the pain reports from 12 patients with osteoarthritis over a 3-year period, in association with meteorological data. This study claimed that eight of the 12 subjects had pain that was weather-sensitive, with the most pain occurring with increased barometric pressure.
Individuals with weather-sensitive knee pain often claim that they can predict changes in the weather based on the level of pain in their knee. Some try to combat this by checking the weather forecast in an attempt to mentally prepare themselves for an increase in pain, should certain weather conditions arise. Others claim to “feel it in their bones” and can accurately predict rainfall due to the increased pain in their knee. However, despite being able to subjectively feel these changes, there have been conflicting reports as to whether or not weather-sensitive pain is actually associated with changes in weather.
Causes of Knee Pain
Osteoarthritis is the most common knee condition associated with pain suffered during changes in the weather. Osteoarthritis occurs in the knee with the breakdown of cartilage that covers the end of bone within the joint. The main role of cartilage is to absorb shock and allow the joint to move smoothly. As cartilage wears away, knee pain and difficulty moving occurs. When changes in the atmospheric pressure occur, such as when it is colder outside, this causes the soft tissues within the body to expand. If the cartilage within the knee has been worn away, the bones within the joint will rub together and cause pain and stiffness in the knee. This expansion can cause an increase in swelling and knee pain, contributing to the flare of arthritis and discomfort. When the pressure decreases it allows these and other fluids to flow more freely, when there is already swelling in the joint this can cause increased pain and limitation. Bodily users internal and external environmental cues to initiate day-to-day on an hour-to-hour basis, routines. Changes in these environmental conditions may modify the severity of a specific disease due to the systems that initiate routine having to adapt and respond to these changes. Given the strong influence of weather on people’s day-to-day activities, it is understood that osteoarthritis sufferers, especially those with knee pain, may experience changes in their symptoms during various types of weather. The connection between meteorological conditions and symptom variation remains a well-known albeit understudied clinical phenomenon. Osteoarthritis affects more than 300 million people worldwide and is the most prevalent chronic condition and one of the leading causes of disability. As the regular and age distribution of the general population continues, osteoarthritis is expected to jump to the fourth leading cause of disability by the year 2020.
The Relationship between Weather and Knee Pain
The formation of a relation between weather and knee pain is not a new discovery. Its incidence dates back over 1500 years to Hippocrates who wrote ‘Physicians must be acquainted with many things and assuredly with the weather’. However, the lack of scientific evidence meant this did not gain widespread acceptance and weather became regarded as an old wives’ tale. The detection that weather does impact on some arthritics came purely by accident. A study conducted between 1955-6 was aimed at identifying the social effects of weather on the elderly. The fact that there was no association between arthritis and weather surprised researchers. Then in 1960, following some preliminary studies in 1957, Dr. John Hollander observed that a patient’s description of arthritis as ‘more painful in the winter’ was commonplace. With this public opinion confirmed by the Longitudinal Study of Aging in 1981, it was by now unanimously agreed among arthritics and was thus suggested to be included as a criteria for OA by the American Rheumatism Association in 1965. With the consistent findings of many studies throughout the twentieth century, the all too familiar statement ‘my joints tell me the weather’s changing’ was now substantiated.
Coping Strategies for Managing Knee Pain in Different Weather Conditions
The most practical advice would be to stay in environments with controlled temperature, such as air-conditioned places. It is best to engage in indoor activities and try to avoid strenuous activities during the peak hours of warm days. This is because the heat from the late morning to early evening is most oppressive. It is important not to increase fluid loss, so remember to drink more fluids to avoid dehydration. Elevation of the affected joints can also help to relieve pain and prevent the swelling of the knees. Remember not to consume alcohol and try to keep the weights of the individual belongings to a minimum. Alcohol increases fluid loss, and heavy loads make the pressure on the knees greater. This set of advice will also be suitable for coping with knee pain in rainy weather.
Singapore is a country with weather that is consistently hot and humid. In our equatorial climate, the daily temperature ranges from 27 degrees to 35 degrees. It is difficult for Singaporeans not to feel the discomfort of warm weather. Most people living in Singapore are already used to warm weather, but increased warmth and humidity may aggravate certain medical conditions, such as rheumatoid arthritis. The muscles, tendons, and ligaments can be affected by the barometric pressure and humidity. When it’s warm, the blood vessels tend to dilate, which increases the blood flow to the warm areas of the body. This can result in increased swelling and, in turn, causes pain.
Hot and Humid Weather
Hot and humid weather can increase swelling in the joints. This is due to increased blood flow near the skin to help the body dissipate heat, resulting in more liquid being delivered to the skin and surrounding tissue. In addition, patients with knee osteoarthritis have also been reported to experience an exacerbation of pain and stiffness due to the hot temperature. This can make exercising to help control weight, which is key to reducing the mechanical load on the knees, a particularly arduous task. Given that Singapore’s weather is generally hot and/or humid, the above would seem a common problem for patients with knee osteoarthritis.
There are certain coping strategies and precautions patients with knee pain can adopt to manage pain in different weather conditions. In general, many patients feel that the weather does affect their pain. In a study on 200 patients with osteoarthritis by Tufts-New England Medical Center in Boston, when asked if they noticed any changes to the condition of their knees based on weather conditions, 75% of the patients reported having an increase in pain with the onset of rain or in colder conditions. This is also supported by a survey conducted among a group of 151 patients with knee osteoarthritis in Japan, in which approximately 60% of the patients reported that there was an association between their knee pain and the weather. Nevertheless, around half the patients are unable to discern a specific weather pattern with regards to knee pain and many others have different “weather predicting pains” and “preference weather conditions” of which they are not uniform in agreement with. This is indicative of the heterogeneous nature of osteoarthritis in terms of the pain experienced and pathological process.
Cold and Damp Weather
However, it is believed to be due to the effects of low pressure on the body. When there is a reduction in the surrounding air pressure, the pressure inside the body’s tissues can cause expansion of swollen tissue. Additionally, low temperatures cause an increase in pain sensitivity by slowing the conduction of impulses in pain fibers. Cold, damp weather can also cause stiffness in the muscles and joints, increasing the difficulty of movement for knee pain patients. Movement is encouraged to keep muscles strong and flexible, directly benefiting the support and function of the knee. However, this is particularly difficult in an environment where adverse weather increases pain and further decreases mobility.
In Singapore’s hot and humid environment, living in air-conditioned rooms is a common and effective coping strategy for knee pain patients. This is not the case for coping with knee pain in cold, damp weather, particularly when indoor environments in Singapore are not designed to conserve heat. The changes in barometric pressure associated with cold, damp weather have been claimed to exacerbate knee pain. In a study examining the effect of weather on osteoarthritic knee pain, it was found that every 10-degree drop in temperature corresponded to an increase in pain. The mechanism behind this has yet to be fully understood.
Rainy Weather
When rain is anticipated or begins to fall, it is advisable to stay indoors and rest, as people with knee OA have been found to be more sensitive to changes in weather and may be susceptible to injury if they continue to push themselves. Alternative activities to keep a person active and maintain muscle strength and flexibility can be performed at home, such as tai chi or general purpose exercises. If outdoor activity cannot be avoided, it was suggested that using a walking aid can help prevent stress being placed on the knees. Knee pain aside, the use of a sturdy umbrella can also help prevent slips and falls on slippery surfaces, which may cause other injuries in addition to exacerbating OA. With regards to footwear, it was mentioned that shoes with good grip and ankle support are important for injury prevention in wet weather, though this may not always coincide with shoes that have good cushioning and support for the knees. If this is the case, consideration can be made to using an additional supportive insole inside the shoe.
Coping with knee pain triggered by rainy weather was the most discussed topic during these sessions. It was suggested that individuals in pain from osteoarthritis (OA) pay greater attention to the weather forecasts, so that they may anticipate the weather and take preventative measures. This may include planning travel or outdoor activities to avoid being caught away from home in the event of rain. This is particularly important in countries with a monsoon season, as heavy and prolonged rain can seriously impact the daily lives of sufferers. In such cases, it may even be worth considering temporary relocation to a drier climate, perhaps for the duration of the wet season. This is a big decision to make and must be weighed against the disruption it may cause to normal routines and obligations.
Dry and Windy Weather
As the majority of these patients are able to attribute their pain change to the weather, a loss of confidence in their body’s ability to handle the changes in the weather is experienced, leading to apprehensive behavior changes designed to protect the arthritic joint from adverse conditions. Reactions are varied, but some patient-reported reactions include: “I would feel depressed in my room on my own,” “I would take no notice, but the pain would force me to take notice and then I would take some anti-inflammatories,” and “I would try to get some physiotherapy treatment sessions.” In more severe cases, some patients are considering weather or a change in location in an effort to reduce potential increase in knee pain. This may be due to the proven implications of persistent pain on quality of life and an increased desire to avoid pain triggers in the elderly. This would be a tough time for someone suffering from knee osteoarthritis, as it is difficult to remedy a problem arising from weather and very few effective personal coping strategies for weather-sensitive medical conditions exist.
When the weather is hot, humid, rainy or cold and damp, worsening of knee pain is commonly reported by over 67% of patients with osteoarthritis. However, a study discovered that the highest correlation (82%) of worsening symptoms of knee osteoarthritis was with dry and windy weather (alteration in our fiber analysis). The pattern is quite consistent and in 80% of patients, a sustained pain increase occurred on one or more occasions.
