Skip to 0 minutes and 5 secondsIn very common parlance, we talk about getting stiff as we get old. And, indeed, that's absolutely true. That's one thing that's happening. Our ligaments are changing their properties. They're no longer as stretchy or as flexible as they used to be. For example, let's have a look now at how Ali walks. Look at the length of her stride. She's confident. She can look up. Her upper body is moving against her lower body, enabling very, very fine control of gait. If you watch her coming back again, she doesn't need to think about how her foot is making contact with the ground. She can feel her foot making contact with the ground. She can use her toes to detect the ground's irregularities.

Skip to 0 minutes and 55 secondsI cannot change the motion of my head from side to side and turning around independently of my shoulders. And certainly, I'm very poor at moving my pelvis independently of my thorax, because I'm old, I'm stiff, I move the whole of my trunk at the same time. And that's one of the reasons you see me waving my arms around simply in order to have something which balances the forces under my foot but in a very second-hand sort of way. We start to lose control at a muscular level, at a force level of our balance. So there isn't as much muscle around to control unwanted rotations in my body. The posh word is sarcopenia, which is loss of muscle fibre volume.

Skip to 1 minute and 43 secondsNow looking from the front, you get another factor. Look at my lower legs, look at the position of my feet, and you'll see that I place my feet further apart than Ali. This is a natural reaction of elderly people to a feeling of instability. If you can see my whole body, essentially at this point, I'm balancing on my leg. I can't stay here very long because at this point, I'm balancing - as you can see, I need to bring my foot down. And now, what's called my base of support is the space between my two feet. But watch me when I start walking, and you'll find I start doing that because I'm insecure about my balance.

Skip to 2 minutes and 31 secondsAnd actually, this is the very worst thing that old people could do. But even I, who know something about it, make that mistake. We're losing brain cells. We're losing acuity of vision. We're losing our colour sensitivity. We're losing - and this, for anyone who's ageing, must ring true - our ability to look at things in low-light. I can no longer read easily in low-light situations although I'm blessed with relatively good eyesight. Looking at fast-moving objects presents challenges for older people. Listening to sounds presents problems for older people. And, of course, as we get older, we're moving more in urban environments because we can't as easily walk out in the countryside.

Skip to 3 minutes and 19 secondsSo a greater amount of our time is spent walking in cluttered environments with lots of sound, lots of noise. Then on top of that, what do old people like myself need to do a lot of the time? Cross roads. Talk to an old person, what they don't like to do is cross roads. Talk to me, I hate it. What we have simulated in this lab here is actually starting to look at that, which is the big problem which old people have with ground irregularities. And this is a good case in point. For old people, being able to detect irregularities in the ground, both with vision, is difficult because the contrast between the plates we've got there, for example, is reduced.

Skip to 4 minutes and 3 seconds3D vision is not as good as it was. So we can't really, again, detect the height differences. If we're crossing a road, we're maybe watching out for a car moving. We're not very good at tracking car speed. If you survey old people, what are they most scared about, what keeps them from healthy exercise, it's being safe on pavements and safe in crossing roads. It's said time, and time, and time again for elderly people living in the community. Now a different situation, of course, with elderly people living in care, where almost a lack of stimulation becomes a problem. You're no longer challenging your brain at all.

Skip to 4 minutes and 43 secondsSo there is a balance to be made between enough stimulation because we need stimulation - we need reference, as I've said, for walking - and too little stimulation. Young people, have you tried walking, as I do normally, with two walking sticks and trying to carry some shopping? I bet you can't do it. It's dreadful. It's awful. A lot of people who are not elderly don't recognise that. And this is one of the everyday problems in helping elderly people live normal lives is to deal with simple things like going shopping. And that's where our focus should be. What's normal? What's healthy? How can people enjoy their lives? And how can we ensure lifelong well-being?

How does the way we walk change with age?

Gait disturbances are a common medical problem in old age. After the age of 70, 35% of people have abnormal gait and after 85, gait changes are found in the majority of people. In this video, we rejoin Professor Robin Crompton to discuss some of the common symptoms and impacts of changing gait.

Robin compares his own gait with that of a younger volunteer. As Robin walks, notice his slower gait speed and shorter stride length; these are common occurrences in older people.

Reduced mobility markedly impairs quality of life and can worsen many of the symptoms associated with gait disturbances. Robin discusses some of the everyday tasks that he struggles with, such as crossing roads and carrying shopping.

Can you think of any other challenges? Are there any tasks that you or someone you know finds difficult?

Share this video:

This video is from the free online course:

The Musculoskeletal System: the Science of Staying Active into Old Age

The University of Sheffield