Week 6 Reading - Balancing Act

Question 1

Fall prevalence

Answer 1

 Evidence suggests our ability to balance (one of humanity’s hardest-won evolutionary skills) is beginning to fade.
o Falls resulting in serious injury or death is increasing even in young people
o And are occurring when people are sober, or walking/standing
o Globally falls are the second biggest cause of accidental death behind traffic accidents
o This number has doubled between 1990 and 2017
o Risk of losing balance increases with age but recent estimates suggest the incidence of falls is rising at a rate that oustrips what would be expected for a growing, ageing population – suggesting younger people are falling

Question 2

Why is balance difficult for humans?

Answer 2

 Humans are bipedalists (with our torsos above our feed). We are the only species to use this as our primary mode of transport, and it’s inherently unstable due to our bodies being top heavy
o To confound this our centre of. Gravity sits high up at pelvis height and slightly forward of our ankles

Question 3

Cognitive aspect of balance

Answer 3

 To maintain balance we use a vast brain-body network to integrate information from our muscles, eyes and vestibular system
o This is a computational challenge
o The cerebellum plays a key role
o It’s believd our ability to rapidly react to different situations is thanks to the brain making predictions based on previous experience which may happen via the cerebellum and the closed loop circuits it forms with the motor cortex

Question 4

Role of cerebellum in balance

Answer 4

o Known to be involved in movement control
o Recently evidenced to have a role in fine-tuning thoughts and emotions too which may explain the link of poor balance and mental health conditions. It could also explain why cognitively demanding tasks can impair balance
o Walking, which is just a better coordinated drunken stagger is made smooth by the cerebellum as it makes micro-corrections mid-stride. This is because the ibrain keeps tabs on the position of the pelvis and adjusts the leg position accordingly

Question 5

Factors influencing balance

Answer 5

o Pregnancy
o Illness
o Injuries – particularly to the legs
o Inflammation – linked to obesity, stress, injury and infection can also affect the way we walk and increase the risk of falls

Question 6

Evidence for the decline in balance ability

Answer 6

o When people are asked to stand on one leg with eyes open or closed, it shows balance declines from early 20’s to 30’s onewards
o In midlife there is an increase in the likelihood of serious falls tht is getting wose

Question 7

 Causes for decline in balance

Answer 7

o Children aren’t moving enough – stability is built up by trial and error
 Less experience to draw upon
 Weaker balancing muscles
* 10 yr olds in England were 20% weaker in 2014 than their 1994 counterparts

Question 8

Why are women worse at balancing

Answer 8

o Balance is seen to decline around age 50 with the cerebellum being the first region to show deficits and particularly so in women
 May be due to the role of Oestrogen which has a protective effect on the brain and declining levels of the hormone during menopause

Question 9

Specific exercises to mitigate balance issues

Answer 9

 If you can’t balance with your eyes closed for 30 second balance needs to become a priority
 Standing on one leg is good as it taxes the balance system as a whole and the eyes-closed variation removes the help of vision
* If you feel the wobble in your feet and ankles, rock back and forth between the heel and toe to strengthen the muscles. Also do things like picking up a marble or pen between your toes
* Be barefoot indoors to keep the feet it and strong
 Hit the trail – bike, run or walk outdoors to tax your balance system.
 Swimming ins’t good to train balance as there is a need to resist gravity

Question 10

Approaches to improve balance

Answer 10

o 1. Balance training; standing on one leg, balancing on a ball, practising heel to toe walking on a line
 One study founds, older people need to do 36- 40 training sessions of atleast 35 mins whilst people under 40 only need 16-19 sessions of 15 minutes.
 Training our balance and strength can also reduce the fear of falling
o 2. Cognitive training that engages part of the brain responsible for motor function and other complex tasks linked to the cerebellum may reduce the cost of thinking whilst walking. (use it or lose it basis)
 One study found that people who did 100 days of cognitive training over 6 month period had less shrinkage in the cerebellum that those that didn’t
 Eg. Tai chi – incolves focussed attention and a series of fluid physical movements – has been shown to improve balance, boost cognitive skills and reduce the fear of falling (the number one risk factor for falls)

Question 11

Poor balance and links to mental health

Answer 11

 Links to mental health
o Depression, anxiety, schizophrenia and other mental disorders are known to affect balance – influencing both gait and standing posture
o People with depression have a more stooped posture with slower movements which increases the risk that if they stumble any righting movements will happen too slowly.
o With schizophrenia, mental distress symptoms are accompanied by swaying posture – linked to issues with integrating visual information with other components of balance.
o For anxiety – the fear of falling can paradoxically affect posture to make falling more likely
o The relationship between balance and mental health might go both ways – to improve your balance could improve your mental health

Question 12

Evolutionary hypothesis for balance

Answer 12

o Evolutionary hypothesis suggests bipedalisms began when our ancesters were living in trees 15 million years ago. These tree-ancestors began standing up more and holding branches which gradually became independently balancing