Studies attempt to identify how writing changes as we get older. Down strokes take longer. Loops and curves in our cursive become less secure. They wobble and tremble. It seems that our writing becomes less automatic. It takes longer. We are more inclined to review what we are doing. We need to visually check what is going on. The pauses change our signiature.

The Ageing of the Hand

Hands suffer from the same age driven changes as the rest of our body. They are however extremely complex “instruments”. To start with there are twenty-nine bones. That means that there are many small joints. There are also three bones found in no other primate. These are in our thumbs and allow them to bend.

We need to add 26 different muscles in each hand. Half are in the hand itself. The rest are in our arms but “operate” the hands. Each muscle in turn must be attached to the bones with tendons. We need 126 ligaments which make bone to bone attachments. We need a nervous system to operate the whole lot and a blood system to give it energy. There are three main nerves in the hand. There are another forty- five nerves which have specific names. We have two main arteries serving the hand. Our skin is extremely sensitive on our hands and we need a sensory system to feed back to the brain.

All of the components age in the same way as their counter parts in the rest of the body. The hands suffer from sarcopenia or the fading of muscle strength (See Newsletter #158 Sarcopnia"). By the age of eighty some people we can lose 50% of their muscle mass. The effect is to make it more difficult for us to pick up things. This is not helped by the fact that our fingernails grow more slowly when we age.

Signals in the nervous system normally travel at 270 miles an hour. It takes time for signals from the hand to reach the brain and it to respond. With age that time increases making “hand-eye” co-ordination more difficult.

At the same time the sensitivity of the skin is declining. The standard tests use two rods as small as a pin head. They are placed next to each other, and we are asked whether we feel one or two rods. They are then moved apart by a small amount and the test repeated. Our fingers are the most sensitive parts of our body. “Two-point discrimination” is less than one millimetre for the fingertips of young adults. That is we recognize that there are two rods when they are only 1mm apart. It is about fifteen millimetres for the forehead and thirty-five millimetres for the forearm and back(see Newsletter #028 Out of Touch"). The threshold increases by 1% per year between the ages of 20 and 80. It can accelerate after that. We need bigger keys, spaced further apart on smartphones and keypads.

The other parts of our hands are not spared. Blood flow to the hands declines with age. It is no accident that older people tend to get cold fingers. Reduced blood flow means tendons stiffen and ligaments even more so. Morning stiffness of the hands as we age is common, even without the danger of arthritis

It is hardly surprising that the complex art of handwriting suffers as we age. We may even be tempted to use a keypad!

Reading Health from your hands

We have a fortune teller read the palms of our hands to tell us about the rest of our lives. It turns out that instead we should measure our grip strength. A recent longitudinal study use grip strength as a predictor. It is easy to measure and has been used in many studies. It turned out that grip strength was a better predictor of when you were going to die than any other variable. The hands age along with the rest of your body. Grip strength is a reasonable measure of that ageing and hence is a good predictor. There is no indication that it is causal. Sorry, increasing your grip strength alone will not make you live longer.

Ageing Hands can be Improved.

Yes we should use moisturizer and sunscreen. That will preserve the skin. We can go much further and repair some of the declines. The best examples are stoke sufferers. They often lose some of the functionality in one of their hands. They are able to repair a lot through exercise. It was not a quick solution and requires support. The exercises were simple but boring! Progress is slow but over months the muscles , nerves, tendons and ligaments can be retaught. There are many general exercise programs for hands, wrists, strength and flexibility. They cannot stop ageing but they can slow the onslaught.

I would like to say that the decline in my handwriting is only down to ageing. Unfortunately it is more likely to be due to our old friend: “use it or lose it”.