My Achilles Heel

Last week I was in a bit of a state: I managed to rupture my Achilles tendon while playing badminton.

An apparently rare badminton-induced injury, my memory of it happening is a bit vague, perhaps because my mind is trying to protect me from the horror of it. What I can remember is hearing a bit of a “pop” and feeling an odd sensation in my left heel, like cords stretching and tearing. I also recall the pain being instantly sharp and intense, as if someone wearing sharp stilettos had kicked me solidly in the back of the heel. Sadly, I had to concede the game after only two rallies.

Having been rescued from my plight, the pain thankfully subsided and I was “rushed” to A&E (as soon as we’d finished watching England beat South Africa). We went to Addenbrooke’s Hospital in a bit of a state of dread, because, let’s face it, experiencing an A&E department, especially on a Saturday night, is not comparable to a walk in the park.

Nevertheless, I was immediately impressed. A helpful orderly brought over a wheelchair as soon as he saw I couldn’t walk (I was hitching a ride on the back of my heroic, but quickly tiring, fiancé). We huddled down for the wait, and a bit later the busy nurse on reception came over and asked if I needed any painkillers. How did she remember me in that mass of bodies? Despite the long three-hour wait, it was exactly what we had been told to expect, and the people-watching opportunities there were very entertaining.

Another two hours later, we left the hospital with my left leg in plaster almost up to my knee, my foot pointed continuously downwards like an overenthusiastic but totally incompetent ballet dancer. The reason for this, the doctor explained, was that the pointed foot makes the torn ends of the Achilles tendon meet so they can fuse back together again (in 8 weeks – 8 whole weeks in plaster! My mind reeled). My first efforts on crutches were a shambles of co-ordination. Think Bambi on Ice.

The next week was quite difficult, and I’ve had many eye-opening epiphanies along the way. My first epiphany was that I’ve been tremendously lucky in my 30 years of life not to have had an injury like this before. I’ve only ever broken my big toe and that was over half my life ago (a fat horse stepped on it), and I could still hobble around. So not being able to walk was an entirely new experience for me, and it was far from good.

Leading on from this, my second epiphany was how precious our bodies are, how lucky we are to have two working legs and feet, and how we shouldn’t take them for granted. I know that sounds ridiculously obvious, and if, reader, you don’t have two working legs or have had to use crutches for an extended period, you must think me extraordinarily naïve. But please forgive me: I am only human. Humans make grievous assumptions and diabolical errors of judgement, as 2016 has so beautifully exemplified. Apologies, I’m getting off topic.

I’m quite active, cycling to and from work every day, playing badminton 2 or 3 times a week. I go on the occasional run. I’m also a bit of an independent soul. So it was with misery that I had to rely on my (again, heroic but quickly tiring) fiancé to fetch me cups of tea; help me in and out of the bath; run around the flat searching for stuff I had misplaced. Etcetera. I even started to dislike myself a bit. Despite my fiancé’s reassurance, I thought I sounded bossy and entitled, and I even started getting tired of saying “thank you” all the time. I was slightly passive-aggressive, my frustrations bubbling to the surface like a demonic personality geyser.

I still went to work; I wanted to try to carry on as normally as possible. The corridor leading to my desk never seemed so long. I broke into a sweat just looking at it. You get a lot of attention when you are in plaster and on crutches. The looks can be sympathetic, curious, and/or confused. You feel a bit scrutinised. Yes, I do have a massive ski sock over the end of my plaster. It’s the new fashion trend, don’t you know? Yes, I am wearing exactly the same trousers I’ve been wearing for the last three days because nothing else fits over my gigantic bandaged leg. And doors – oh doors, why do you have to be so heavy and cumbersome?

Another epiphany was that people can be extremely kind. Even go-out-of-their-way kind. A security guard walking with me for 5 minutes so he can hold all the doors open for me. A stranger on the street seeing me struggling to get out of a taxi and rushing over to help me down. A lady at work leaving a meeting to run over to help me retrieve my fallen crutch. It goes on. And that’s just in a week. It’s made me realise that we should celebrate people’s everyday kindnesses, and we mustn’t take them for granted. Thank you, ruptured tendon, for restoring my faith in humanity.

Have you ever read about your Achilles tendon? I have, and it gave me a a completely new appreciation of it, which I wish to share with you. Also known as a heel cord, it is the only thing connecting your heel bone to your calf muscles. In other words, it is the only part of our body that allows us to do everyday things, like stand on tiptoe, point our toes, and flex our knees.

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The Achilles tendon connects your heel bone with your calf muscles. Image source.

Not surprising then, that having an “Achilles heel” refers to a particular vulnerability or point of weakness in an otherwise invincible façade. This relates to the story of the ancient Greek war hero, Achilles, who as a baby was dipped into a river by his mother, the immortal nymph Thetis, to give him a magical coating of invincibility. His mother held him by the heel to dip him into the river and so this heel never received the coating of invincibility. Henceforth, that heel was his one vulnerability and he inevitably ended up dying from a wound inflicted there.

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Baby Achilles being dipped in the river by his mother to obtain a magical invincibility coat. Source: Peter Paul Rubens

In a chat with friends we started wondering: what would have happened to an ancient caveman if he had ruptured his Achilles tendon? Did his fellow cavemen and cavewomen look after him despite his disability? Or would they leave him to perish, his lack of usefulness to the group making him a liability, an extra hungry but useless mouth to feed?

Understanding the evolutionary history of the Achilles tendon is a very challenging task for scientists. This is in part because soft tissue does not fossilise, so it is difficult to identify what the Achilles tendon was like in our ancient human and more distant chimpanzee ancestors. We do know that the human Achilles tendon is the longest (relative to total muscle length) of any primate, which is thought to be beneficial for our bipedal locomotion and endurance running (Bramble and Lieberman, 2004).

Nevertheless, what scientists have been able to do is look at the insertion site on the calcaneal tuber (the half of the bone closest to the heel) in fossils to reconstruct tendon morphology, using high-resolution three-dimensional microcomputed tomography (micro-CT). This is basically a way of taking an x-ray picture of something really small in 3D to see it up close. However, this technique has so far produced limited results: despite the differences in tendon length, no differences have been found in tendon insertion site properties in chimpanzee and human heel bones (Kuo et al., 2013). So, before we can understand what the fate of a caveman with an Achilles injury would have been, we still need to properly trace the evolutionary history of the tendon.

Looking at the consequences of disability in non-human primates provides some clues. For example, in Japanese macaques (Macaca fuscata), disabled adults will change their behaviours to suit their existing physical situations and occasionally invent new ways of doing things (Turner et al., 2012). Similarly, in a chimpanzee population suffering from disabilities obtained from snare injuries, one chimp with near-paralysis in both hands compensates for his inability to scratch his back by holding a growing liana plant taut while making side-to-side body movements against it. Even able-bodied chimps copy him, making their own natural ‘back-scratchers’. Having learned this behaviour by watching the disabled chimp, this reveals disabilities in a social group could even have positive effects on group individuals (Hobaiter and Byrne, 2010).

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Disabled chimpanzees (Pan troglodytes) change their behaviours and use tools to help their circumstances. Healthy able-bodied individuals will even adopt these behaviours to their own advantage. Image source: Ikiwaner.

Whatever the consequences of an Achilles tendon rupture, I am certainly glad to live in a modern world with wonderful hospital A&E departments. My plaster cast has now been removed, to reveal the horror-movie-like bruising and bumps beneath, and replaced with an aircast walking boot. (Physiotherapists perceive this as just as good as having surgery these days, and the early mobility in the calf muscles helps with rehabilitation).

Sadly, I no longer have an excuse to zoom around on the mobility scooters in Tesco. But at least I can forage and fetch tea on my own, and my fiancé can put his feet up.

References

Bramble, D.M. and Lieberman, D.E. 2004. Endurance running and the evolution of Homo.
Nature, 432, 345-352.

Hobaiter, C. and Byrne, R.W. 2010. Able-Bodied Wild Chimpanzees Imitate a Motor Procedure Used by a Disabled Individual to Overcome Handicap. PLOS One, 5, e11959.

Kuo, S.R. et al. 2013. The Effect of the Achilles Tendon on Trabecular Structure in the Primate Calcaneus. Anatomical Record – Advances in Integrative Anatomy and Evolutionary Biology, 296, 1509-1517.

Turner, S.E. et al. 2012. Disability, Compensatory Behavior, and Innovation in Free-Ranging Adult Female Japanese Macaques (Macaca fuscata). American Journal of Primatology, 74, 788–803.

 

The Wonders of Planet Earth Captured on Camera

Last night I watched the latest episode in the BBC’s second series of Planet Earth (aptly named Planet Earth II). Coming ten years after the first series, it uses the latest technologies to capture breath-taking, never before seen footage in ultra-high definition (4K UHD). The animals featured in it appear so real you could almost reach out and touch them. The programme is set to awe and inspire you more than ever, as it did me.

You would think that it would be difficult to top the racer snake vs. marine iguana stand-off and komodo dragon wars in the first episode. But the second episode, while maybe not so dramatic, was just as stunning. Showcasing life in the planet’s mountains, I actually held my breath for several moments during scenes featuring the snow leopard, Panthera uncia. As the programme’s narrator, Sir David Attenborough, points out, these animals are extremely rare. In their lonely habitats of the vast mountain peaks of the Himalayas in Central and Southern Asia, there are estimated to be only about 2,500 individuals reproducing in the wild.

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The snow leopard, Panthera uncia, is listed as Endangered by the IUCN.

So it was with extreme awe that I was able to watch these rare leopards on my television last night. Not only had the programme captured these magnificent big cats on camera – using the latest remote-sensing video cameras – but they had filmed it close-up performing several behaviours that we have never been able to see before.

Like other leopard species, these cats rarely come into contact with one another, instead living a lonely life padding around their large territories communicating remotely with various rituals. For the first time, we were able to witness these communication rituals: a female leopard wiping her cheek pads and spraying urine on particular rocks to mark her presence, and roaring on a snowy peak, the grating calls echoing eerily among those vast lonely mountains.

Given the rarity of these beautiful creatures and their lonesome habits, it is amazing that we were able to see not just one leopard, but four, at one time. The scenes that followed were more exhilarating than you could imagine. My heart was in my mouth. The female leopard, with her almost-grown cub in tow, was in heat. Her scent and roars had attracted two huge males that threatened to kill her cub. She mated with both of them after some ferocious fights. The cub managed to get away and, despite an injury to the mother, they were both seen again a month later. The cub had finally been weaned and was making her own plea for survival among those harsh snowy peaks.

You might think that that this would be the one stand-out highlight of the episode, but still, the wild golden eagles (Aquila chrysaetos) fighting over the carcass of a fox was another remarkable feature (it also reminded me of one of my previous posts).

Accompanying footage of a ‘bird’s eye view’ of a golden eagle in flight – actually the footage from a tandem-paragliding cameraman  – may have caused some controversy, but in my opinion, it only added to the drama and was testament to the extraordinary efforts of the show’s producers to entertain and delight us.

Choosing the best of the nests makes sage grouse good mothers

Recent research published in  The Condor: Ornithological Applications has shown that greater sage grouse mothers (Centrocercus urophasianus) can choose nesting habitats that better ensure the survival of their chicks after they fledge.

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Female greater sage-grouse (Centrocercus urophasianus) [front of image] can select nesting habitats that ensure their offspring survive. Photo credit: Jeannie Stafford/USFWS.
Evolution not only drives animals to act to benefit their own survival (direct fitness) but also that of their own offspring (indirect fitness). Maximising such lifetime reproductive success is probably what drives us to protect our own children.

But can animals actually make active decisions that benefit their reproductive success? This is the question that Dr Daniel Gibson and his colleagues set out to answer in their study of the greater sage grouse.

These birds are the largest grouse in North America, inhabiting open grassland habitats that make them particularly vulnerable to predators. The species is classified as Near Threatened by the IUCN Red List. They have a complex mating system, whereby males gather in groups (leks) to perform lively, colourful mating displays to attract females [see picture]. This means that females get to be extremely picky about who they mate with.

Dr Gibson and his team found that females are not only choosy about their sexual partners but also are picky about where they nest. They tend to choose nesting habitats with characteristics that ensure reproductive success: specifically, greater shrub cover and forb (flowering plant) diversity. By observing over 200 mothers over a period of 8 years, they found that these habitat features predicted the survival of chicks after fledging.

This means that even our feathery friends can make active choices that determine the survival of their offspring, which is pretty impressive. What isn’t so clear is whether the mothers themselves were more likely to survive – were they also acting to protect themselves as they sat helpless on their nests? Or is their behaviour purely selfless?

Whatever the answer, it is likely that many other animals are able to protect their young by making these real-time decisions – what can be termed ‘behavioural plasticity’ – something that evolution is likely to promote in order to maximise indirect fitness and pass on genes to future generations.

Knowing this will also help conservation efforts because land managers now have clues about where these birds are most likely to nest, and hence which habitats they should protect the most.