Objectives
- Understand the influence of physical inactivity and the risk of OA development
- Understand the safety of physical activity for knee OA
- Understand how physical activity is measured clinically and in research
- Understand what the benefits and harms of physical activity are
- Know the different between physical activity and exercise
- Know what the average levels of physical activity are for people with knee OA and joint replacements
- Understand strategies to increase physical activity in knee OA and TKR.
Physical Activity
Watch the video below to understand more about physical activity.
Physical activity is defined as bodily movements produced by skeletal muscles that require expenditure of energy, including leisure, sporting, occupational and household activities
Physical activity guidelines recommend at least:
- 150 minutes of moderate to vigorous activity/week for adults aged 18-64 years old
- 30 minutes per day of moderate activity for adults aged 65 or older
(Australian Government Department of Health, 2019).
Steps per day can also be used as a determinant of physical activity, with recommendations varying between 7000 and 11.000 steps per day.
Physical activity and osteoarthritis
Click on the info button below to learn more about the association between physical activity and osteoarthritis.
Exercise
Exercise is a subset of physical activity that is planned, structured and repetitive; and is aimed at maintaining or improving physical function.
Exercise and physical activity have numerous physical health benefits including delaying all causes of mortality (Zhao et al., 2020), decreasing the risk of developing multiple chronic conditions (such as coronary heart disease, stroke, and type 2 diabetes) and benefiting at least 26 chronic conditions (such as mental health, cardiovascular diseases and musculoskeletal disorders like osteoarthritis)
Exercise therapy can improve functional capacity and reduce disability in people with chronic diseases (Pasanen et al., 2017 – need to find paper).
Exercise and osteoarthritis
Multiple guidelines recommend exercise as a core treatment for hip and knee osteoarthritis regardless of a person’s age, structural severity of the osteoarthritis, functional limitations or pain severity, including NICE 2014, EULAR 2018, RACGP 2018, OARSI 2019 and ACR 2020 (Bannuru et al., 2019; Geenen et al., 2018; Kolasinski et al., 2020; National Institute for Health and Care Excellence, 2014; The Royal Australian College of General Practitioners, 2018).
Exercise is effective in improving function and reducing pain for both knee and hip osteoarthritis, with over 50 randomised trials confirming its positive effects (Juhl et al., 2014). A recent systematic review has found that loading exercise was safe in people with knee osteoarthritis (Bricca et al., 2019)
- The effect size for exercise is greater for knee osteoarthritis (0.49 for pain, 0.52 for function) (Marlene Fransen et al., 2015) than hip (0.38 for pain and function) (Marlene Fransen et al., 2014)
- However, both are larger than the effect size of commonly prescribed medications including NSAIDs and acetaminophen (paracetamol) (McAlindon et al., 2014)
*** Insert chart of effect sizes***
A systematic review by Juhl (2014) looked at the relationship between exercise and knee OA and concluded that:
- Single type exercise programs are more effective than combined exercise programs.
- There are similar effects of reducing pain and disability between aerobic, resistance and performance exercises
- The effect of aerobic exercise on pain relief is increased with increased numbers of supervised sessions.
- Interventions consisting of single exercise type with 3 or more sessions per week had greater effect on reducing pain and disability than those with less than 2 sessions per week.
- More pain reduction occurred with quads specific exercise than lower limb exercises, and when supervised exercise was performed at least 3 times per week.
Conclusion: Optimal exercise programs for knee OA should have an aim and focus on improving aerobic capacity, quads strength or lower extremity performance. Programs should be supervised at least 12 sessions and carried out 3 times per week.
OA action alliance website (https://oaaction.unc.edu/) has some useful infographics: (?can we have a small version of them here?)
Infographics for Guidelines for physical activity:
UK chief health officer guidelines on older adults and physical activity
WHO recommendations on physical activity for people aged over 65
Activity guidelines for adults age 18-65 (courtesy of Tasmanian Dept of Health)
??? Podcast joint action David Hunter interviewing Matthew Williams re tailored exercise programs and OACCP program : https://www.jointaction.info/podcast/episode/b02d61a3/exercising-with-osteoarthritis
Info graphic Osteoarthritis and exercise Created by Alessio Bricca (Twitter: @a_bricca)
Physical activity is defined as most bodily movements produced by skeletal muscles that require expenditure of energy, including leisure, sporting, occupational and household activities.
Physical activity guidelines recommend at least 150 minutes of moderate to vigorous activity per week for adults aged 18-64 and 30 minutes per day of moderate activity for adults aged 65 or older (Australian Government Depart of Health, 2019).
The majority of people with hip and knee osteoarthritis do not meet physical activity guidelines, averaging 50 minutes per week and are less likely to be physically active than their age matched peers (Wallis et al., 2013),
Steps per day can also be used as a determinant of physical activity, with recommendations varying between 7,000 and 11,000 steps per day
A lack of physical activity (walking less than 3000 steps per day) has been associated with an increased risk of developing functional limitations in people with knee osteoarthritis (White et al., 2014)
Although a recent study found no increased risk of knee osteoarthritis with high levels of sedentary behaviour over a ten year period (Chang et al., 2020) this was based on incident radiographic OA.
The same study also found no association between high levels of physical activity and radiographic knee OA, supporting the safety of physical activity in people with knee osteoarthritis (Chang et al., 2020).
A lack of physical activity is a risk factor for multiple morbidities including cardiovascular disease, diabetes and mental health (Booth et al., 2012), as well as falls (Pereira et al., 2008) and obesity. With an increased rate of co-morbidities in people with osteoarthritis compared to those without, optimising physical activity and exercise is an important component in the management of people with osteoarthritis.
People who are less physically active with arthritis have a higher risk of functional decline over a 2 year period when they are less physically active.
People with knee osteoarthritis who are more physically active have reduced chance of depression, reduced pain and improved quality of life and physical function as well as the other general health benefits associated with physical activity (Dunlop et al., 2011; Mesci et al., 2015).
Pain as well as people’s beliefs and concerns regarding the safety and efficacy of exercise may influence people’s activity levels
Walking an extra 1000 steps per day did not increase risk of TKR in people with advanced radiographic knee OA. Replacing 10 minutes per day of very light or light walking with 10 minutes of moderate walking reduced the risk of TKR incidence (Masters et al 2021)
Watch this great video produced by Trek:
Definition of exercise: A subset of physical activity that is planned, structured and repetitive; and is aimed at maintaining or improving physical function.
Multiple guidelines recommend exercise as a core treatment for hip and knee osteoarthritis regardless of a person’s age, structural severity of the osteoarthritis, functional limitations or pain severity, including NICE 2014, EULAR 2018, RACGP 2018, OARSI 2019 and ACR 2020 (Bannuru et al., 2019; Geenen et al., 2018; Kolasinski et al., 2020; National Institute for Health and Care Excellence, 2014; The Royal Australian College of General Practitioners, 2018).
Exercise and physical activity have numerous physical health benefits including delaying all cause mortality (Zhao et al., 2020), and decreased risk of developing multiple chronic conditions including coronary heart disease, stroke, and type 2 diabetes . Exercise therapy can improve functional capacity and reduce disability in people with chronic diseases (Pasanen et al., 2017).
Benefits of exercise: see also tab 1
Exercise is effective in improving function and reducing pain for both knee and hip osteoarthritis, with over 50 randomized trails confirming a positive effect for exercise in people with hip or knee osteoarthritis (Juhl et al., 2014). The effect size for exercise is greater for knee (0.49 for pain, 0.52 for function) (M. Fransen et al., 2015) than hip (0.38 for pain and function) (Marlene Fransen et al., 2014). However both are larger than the effect size for commonly prescribed medications including non-steroidal anti-inflammatories and acetaminophen (paracetamol) (McAlindon et al., 2014). ***insert chart of effect sizes
A key paper, Juhl’s 2014 systematic review of exercise for knee OA:
-Similar effects in reducing pain and disability found for aerobic, resistance and performance exercise
-Single type exercise programs more effective combined exercise programs.
-Effect of aerobic exercise on pain relief increased with increased number of supervised sessions
-Interventions consisting of single exercise type with 3 or more sessions per week had greater effect on reducing pain and disability than those with less than 2 sessions per week
-More pain reduction occurred with quads specific exercise than lower limb exercise, and when supervised exercise was performed at least 3 times per week.
Concluded optimal exercise programs for knee OA should have on aim and focus on improving aerobic capacity, quads strength or lower extremity performance. Programs should be supervised, at least 12 sessions and carried out 3 times per week
Types of exercise include joint specific strengthening, aerobic, neuromuscular, range of movement/stretching, balance, and aquatic. Currently, there are no recommendations or evidence to support one form of exercise other another.
Recommendation for 12 supervised sessions, one form of exercise rather than combined types of exercise.
A recent systemic review found loading exercise was safe in people with knee osteoarthritis (Bricca et al., 2019).
Exercise-strength: 30-40% improvement in quads strength required to improve pain and function.
Exercise-aquatic: Cochrane review-moderate quality evidence aquatic exercise may have small short term clinically relevant effects on pain disability and QoL in people with knee and hip OA (Bartels et al., 2016)
What about people with co-morbidities? Answer: Tailored exercise is safe and effective for people with comorbidities
Adherence: Can be improved through professional disease education, initial physio supervised classes have been shown to be beneficial as a supplement to longer term home ex for pain and function
Joint action podcast David Hunter interviewing Kim Bennell How does exercise help: https://www.jointaction.info/podcast/episode/1b6b61a8/how-does-exercise-help