Chapter 13 - Sedentary behaviour
Part A - Sedentary Behaviour
In the 2019 UK Chief Medical Officers (CMO) guidelines on physical activity,1 adults are advised to aim to minimise the amount of time spent being sedentary, and when physically possible should break up long periods of inactivity with at least light physical activity.
What is the basis for this?
Adults and children increasingly spend time sitting: at a desk or laptop, driving, watching TV or DVD’s, playing computer games or social networking. Occupations have changed, from being physical working to office working with ever increasing hours working at a computer.
Evidence shows that prolonged sitting and a lack of whole-body muscle movements are associated with obesity, metabolic syndrome, type 2 diabetes, cardiovascular disease, cancer and total mortality which are usually independent of daily moderate to vigorous intensity physical activity (MVPA).2 - 9 In particular, TV viewing time is implicated in obesity, with the concurrence of snacking on sweet or fatty foods, low levels of physical activity and inadequate sleep.10-12
It is has also been observed that because TV-viewing is usually after dinner (or with dinner in front of the TV) that this prolonged postprandial sitting may be particularly detrimental for glucose and lipid metabolism.13 Food advertising on TV is also likely to affect eating behaviour.14
It has been thought that this sedentary time is likely to be in addition to the risks associated with insufficient MVPA. An Australian study estimated the extent to which TV viewing time reduced life expectancy. The research compared people who watched no TV with those who spend a lifetime average of 6 hrs viewing a day and found the latter group were predicted to live 4.8 years less. The authors concluded that ‘TV viewing time may be associated with a loss of life that is comparable to other major risk factors such as physical inactivity and obesity'.15
With the strong evidence of the link between sedentary time and poor cardiometabolic health, that this may be a more important indicator of poor health than MVPA levels.16 Thus it may be more effective in the prevention of type 2 diabetes to target reducing sedentary time rather than solely focusing on promoting MVPA.
Until recently, it has also been unclear whether sufficient levels of activity can modify by weakening or removing the damaging effect of prolonged sitting as described above.17,18 A major meta-analysis of data from more than 1 million individuals,19 has explored the associations of sedentary behaviour and physical activity with all-cause mortality.
Results have suggested that across sitting time categories, all-cause mortality was considerably reduced with higher levels of physical activity and eliminated in those who were the most active (60-75 min or more per day of moderate activity).19 This level of activity is beyond the basic level of the World Health Organisation (WHO) and Chief Medical Officer's (CMO) physical activity guidelines of 30 minutes a day (for five days a week) or 150 minutes a week of moderate intensity. For these individuals, there were smaller increases in mortality risk associated with sitting time seen compared with the least active group (about 5 mins/day), even though the risks were not completely eliminated.19
This study also found that, in comparison with other risk factors for health, the increased mortality risk (58%) in those who sit for more than 8 hours/day and are also the least active is similar to that of smoking20 and obesity.21
One would expect similar results when comparing physical activity and daily sitting times and TV-viewing times with all-cause mortality. However, studies have suggested a greater effect of TV-viewing on all-cause mortality,19,22 and although high level activity reduces considerably the risks associated from TV-viewing, it fails to totally remove this increased risk.19
What can we do practically in the workplace and at home to change this behaviour?
One simple way is to introduce the concept of NEAT (Non Exercise Activity Thermogenesis), a term that refers to daily physical activities that are not perceived as exercise or training. By promoting more standing, less sitting and more moving we now know that these activities, however small, are better than sitting still and these small activities accumulate and count towards our daily energy expenditure as well as reduce the sedentary risk factors.
- Promote and support standing meetings. (Standing burns 15 calories an hour compared to 5 an hour sitting)
- Get up from the desk to walk across the office to speak to a colleague rather than phone or email
- Use a standing desk to work from
- Read your ipad/tablet on top of the filing cabinet
- Stand whilst speaking on the phone
- Walk and talk if using a cordless phone
- Use manual buttons on televisions rather than a remote if available
- Get up and move during commercial breaks on the TV
- Park the car on the far side of a car park e.g. at the supermarket
- Using the stairs instead of the lift or escalator
As Health and Social Care Professionals, we may be able to do little to alter the social changes that have occurred over the past few decades. However, by understanding the health problems which have developed from this, we can do more by advising and guiding patients to think about their lifestyle and to address their health risks. Changing patterns of behaviour is not easy, but if small changes are made and this is spread over large populations, then the effect will be significant. Increasing physical activity is essential to mitigate the associated risks for inactivity.
Part B - Sedentary Behaviour and Musculoskeletal Disorders
Simon Everett & Anna Lowe
Sedentary behaviour refers to any waking activity characterized by an energy expenditure ≤ 1.5 metabolic equivalents and a sitting or reclining posture. In general, this means that any time a person is sitting or lying down, they are engaging in sedentary behaviour. Common sedentary behaviours include TV viewing, video game playing, computer screen time, driving and reading.1
Lack of physical activity is a common factor in many chronic conditions2 and inactivity has been directly linked to musculoskeletal changes.3 Physical inactivity is highlighted as a threat to musculoskeletal health across the lifespan.4
Musculoskeletal disorders (MSDs) related to sedentary lifestyles and minimal physical activity are:
- non-specific low back pain
- sciatica/lumbar radicular pain
- neck pain with and without radiculopathy
- patellofemoral joint pain
- hip pain
It has been suggested that the mechanism through which the sedentary behaviour negatively affects joint health is largely related to deconditioning.5 Further studies have shown the greater risk of sarcopenia associated with longer sitting time.6
The following section gives examples of the impact of sedentary behaviour on some aspects of musculoskeletal health:
Low back pain is one of the biggest causes of absence from the workplace,7 accounts for a high demand on healthcare provision, is multifactorial, and common aetiologies of which are; sedentary behaviour, being overweight and obese, and harmful lifestyle choices e.g. smoking, poor diet, poor social interaction.8 Current thinking is moving away from rest and toward active recovery and rehabilitation alongside encouraging lifestyle improvements. Physical inactivity is associated in a clear dose-dependent manner9 with:
- narrower intervertebral discs
- higher fat content of lumbar muscle and fascial tissues
- high intensity low back pain and disability
A systemic review assessed how behavioural interventions compare to no intervention and guideline-based active treatment.10Interventions regarding behavioural approaches to help people better manage persistent low back were seen to yield good improvements in pain, disability and quality of life. Another systemic review and meta-analysis11 of multidisciplinary biopsychosocial rehabilitation (MBR) of patients with chronic low back pain consolidate this holistic approach finding MBR to be more effective than usual care (moderate quality evidence) and physical treatments (low quality evidence) in decreasing pain and disability in people with chronic low back pain.
Lower back pain with lumbar radicular pain/sciatica is common7 and through systematic review and meta-analysis, the risk of occurrence has shown to be reduced with physical activity12 increased with long smoking history, a high serum C-reactive protein level,13 and being overweight and/or obese with a dose dependent relationship.14 Contextualising this with the World Health Organisation and Chief Medical Officers recommendation of 150 minutes of moderate intensity exercise,15 sedentary lifestyle behaviour can be suggested as a causative factor for non-specific low back pain. A systematic review16 highlights the benefits of exercise therapy for non-specific low back pain in regards to function and pain. This highlights the need for patient specific exercise to encourage participation and a move toward a more active lifestyle.
NICE guidelines NG 5917 on low back pain and sciatica call for greater emphasis on exercise and psychological therapies:
- Encourage patients to continue with normal activities
- Consider a group exercising programme as part of the treatment regime
- Consider manual therapies (manipulations and soft tissue massage) but only as part of a treatment package including exercise, with or without psychological therapy
- Consider psychological therapies using a cognitive behavioural approach but only as part of a treatment package including exercise, with or without manual therapies
In conclusion, sedentary lifestyles are a major factor in non-specific low back pain and back pain with accompanying radicular pain and can be treated in many ways with exercise and a holistic multidisciplinary approach being particularly effective.
In relation to sedentary lifestyles, Achilles tendon pathology and pain is seen to be particularly susceptible to lower levels of physical activity19 and Achilles tendon pathology was more common in patients with greater BMI.20 Through retrospective analysis to elucidate the role of BMI in the development and treatment of Achilles tendon pathology, a high BMI was seen to play a role in the development of Achilles tendon pathology, although, somewhat reassuringly, not affecting the response to conservative treatment. It could be extrapolated that Achilles tendon pain could be due to deconditioning associated with sedentary lifestyles and through exercise, reconditioning of tissues along with the secondary effects of exercise such as decreased pain sensitivity21 could be an effective management. There is good evidence of the benefits of graded loading to pathological tendons which can be applied to other tendinous muscle attachment, such as patellar tendinopathy.22 Coupled to this, obesity as a risk factor, has been identified for several types of tendinopathy including: rotator cuff, elbow extensor compartment (tennis elbow), patellar, quadriceps, achilles, and the plantar fascia.23
Sedentary lifestyles, play a part in the development of non-traumatic knee pain. A systematic review found some limited evidence for, amongst other biomechanical factors: weight, BMI, and waist-to-hip ratio.24 Treatment options highlighted have focussed on affecting these, with increasing strength, decreasing body weight, and upper leg flexibility identified as being most effective.
Osteoarthritis of the knee is commonly seen into the later stages of life with a wide range of hypothesis on the cause and effect of arthritis. NICE (2014) guidelines,25 highlight exercise as a core treatment to focus on local muscle strengthening and general aerobic fitness, although people with knee osteoarthritis tend to fall short of physical activity guidelines and recommended daily steps.26
Musculoskeletal shoulder pathology includes: frozen shoulder, rotator cuff pathology, and glenohumeral and acromioclavicular joint osteoarthritis. Pain is frequently caused through falls and degenerative changes in both the rotator cuff and glenohumeral joint, particularly in elderly patients. Whereas exercise has been seen to be a highly effective treatment method for these conditions,27 - 29identification of factors associated with sedentary lifestyles have been made in regards to increased risk of shoulder pathology.30 In a large cross-sectional study assessing associations of lifestyle factors and metabolic factors with shoulder pain and rotator cuff tendon pathology, associations of abdominal obesity and smoking in male and females were clear. Thus, it could be concluded that non-traumatic shoulder pain incidence is affected by sedentary lifestyles and decreased physical inactivity and to affect this, lifestyle changes regarding physical activity and combatting sedentary lifestyles would be of benefit.
Key message: Physical activity is an important part of prevention and management of musculoskeletal disorders. In addition, specific exercises may be important from a qualified professional.
Consider: Auditing your sedentary patients to see if they have been offered any physical activity advice.
Benefits to health professionals: Reduced appointments and pain relief prescriptions.
The Chartered Society of Physiotherapists has postcards to buy and a free pdf download for desk workers or even self use!
A fun 4-minute cartoon video on You Tube entitled – ‘Let’s Make our Day Harder’ may help shift sedentary behaviour and be motivational for some patients.
Proposed review date: December 2021
Chapter 13A - Sedentary behaviour - Factsheet - download
Chapter 13B - Sedentary behaviour and Musculoskeletal Disorders - Factsheet - download
Now part of the RCGP clinical programme on physical activity and lifestyle
References: Can be found in Chapter 18