There are a few theories as to why we first became upright. The latest (and latest to be dismissed) is that we adopted the stance to carry children. Probably the most popular is that it was purely driven out of a neccesity to free up the hands for use as tools and to evolve into a more effective and efficient way of going from one place to another. whatever the reason, this left a strange effect on our body. It meant that the vertebrae that makes up the spine also had to adapt to carry the weight of our ever increasing upright stance. The result of this evolution is a strange series curves - the largest being a inward "lordosis" or inward curve of the lower spine. It's certainly not the most mechanically perfect structure for walking or running, but it makes a pretty good shock absorber - great for jumping out of trees (or planes!)
Another theory for the lordosis is that as our brains grew, the pelvic muscles adapted slightly to make childbirth easier to compensate for the weight and size of the baby's head (try telling that to a woman who's given birth - sorry Mungo, but you've got all this to come!) Because of this, the spine increased its lordotic shape which assisted in maximising the width of the birth canal. (This bit is sourced from National Geographic magazine.) In other words, if a chimp, whose lordosis is not so pronounced, had our brain size, it would be impossible for the chimp to give birth. The larger brain size also needed a strong structure to pivot on.
In my mind (and I don't know if there is any scientific evidence to back this up) We have evolved too quickly. In our hurry to save energy by walking on two feet and use our hands as tools, we became upright long before we had the bone and supporting muscle infrastructure to do so. The result was - back problems!
We've actually managed reasonably well and indeed it's a minor miracle that in the main our joints can take the stresses and strains of everyday activities... err that is if we're not sitting down all day that is. Sitting is great for the joints but not good for the back. Inevitably, there's been a price to pay whatever you do for normal day to day activity. If we're too active, the stresses and strains show quickly; not active enough and the supporting muscles won't develop enough to support the back.
If we start increasing the stresses by applying additional weight, the back or more specifically the intervertebral disks between the individual vertebrae starts to comes off worse.
As I turn the half century, I've discovered that the stresses and strains on the old body are starting to show. Years of carrying stuff in the Forces, pounding the body by intense physical activity and general old age is starting to show. Not only have I had the Achilles injury, but I've felt the old back straining a bit recently under the load of the rucksack. I'm not the only one. Back problems are an issue with many people.
Ah! I hear you say. Simple! Don't carry so much stuff; purify your water; use dehydrated food; ditch the beer. Well... yes, some of those are an option. One isn't! I'll leave you to decide which one isn't! How's about going ultra-light with titanium cooksets and sawn-off toothbrushes? Well, to start replacing all your gear tends to be a bit expensive and you start to move away from the "traditional" bushcrafting ethos.
I have in fact compromised on comfort in a lot of areas and I've ditched a lot of unnecessary kit, but I'm only prepared to go so far, especially for social meets. So without resorting to being really uncomfortable by ditching all our kit, how can we look after our backs?
I don't normally provide advice; but I think I might be qualified enough to talk about this with a physical training background. So I'm going to share my thoughts with you on this.
Of course, knowing how to lift and shift things properly will help. This applies to working in the woods as much as anywhere else. The strongest muscles in the body are the legs and therefore we should use them to maximum effect by bending the legs when lifting a weight, keeping the back straight, looking slightly upwards and keeping the weight close to the body like a weight-lifter. Twisting the spine while lifting or carrying is a pretty dangerous thing to do - so I would advise against it at all costs. (Who slings up their rucksack from the floor and throws it over one shoulder to put it on? Come on... put your hands up!) Have a look here at the correct way to do it (plus more tips).
I've also seen many people carrying heavy logs in the woods by cradling them in front of the body. This puts a strain on the lower back by over-compensation of these muscles. Best to lift it onto a shoulder where the weight is nearer the spine. If you're straining hard, it's too heavy. Use a colleague to assist in lifting and shifting or find an alternative method to move the weight eg ropes. Even chopping wood can cause a back strain. Instead of bending over to chop wood, kneel down or raise the wood being chopped.
Back to load carrying. I've realised that you simply must have a decent rucksack that suits your frame and walking technique. During adventure training in the Forces, we always swapped out military kit for civilian made stuff. There was a good reason for this. Military kit is usually too standardised especially rucksacks and more often than not it doesn't fit the individual. I forgot this principle when choosing my rucksack and, like quite a few other folk, elected for the most popular ie the Karrimor Sabre series (the 75 in my case).
Although robust and flexible, I've found that over the years it just doesn't fit me. Simple as that. There's no adjustable back length and even when packed properly and compressed with the compression straps, the loaded rucksack sags below my centre of gravity and seems to balloon out beyond my shoulders. Even though I don't hike that far anymore, a relatively short one mile walk-in tends to be uncomfortable.
Rucksack fitting is quite important. This post is already too long and I'll refer you to an excellent guide on backpacking light.
I'm not in favour of the current trend of carrying small rucksacks which are loaded to the brim as they don't distribute the weight very well and may well lead to injury. Of course, it depends on how much weight there is in them. If the object is to carry less, then go for it. Packing the same gear in a 35 as a 75 is asking for trouble.
Rucksacks should be packed so that the heaviest weight is distributed evenly along or just to each side of the spine. Therefore, ideally, they should be quite narrow like a technical climbing sack. When packing, perhaps put clothes and lighter items at the bottom of the sack, heavier objects along and against the spine and again lighter items at the top. At a push, it's better to have the heavier items at the top rather than at the bottom - but be careful of the whole thing becoming too top heavy resulting in instabillity. Although side pouches may be handy, it's not a good idea to fill these up too much as you will be spreading the weight beyond that crucial centre of gravity.
Packing in this organsied way does have its problems especially if the rucksack is a top-loader (you've probably found this out already.) Without decent compression straps, you'll soon find that when you put your pack on, all the items will shift about and find their way to the bottom of the pack! You can't win!
But... I have a plan! A cunning one. I'm going to buy the most expensive rucksack I can find!! Well, not quite, but it will at least be a good fit, it will have good compression straps and an adjustable back and it will probably be a front as well as top loader. Sounds like I've already got one in mind doesn't it?
Thanks for the visit.
Pablo.
