Hello again, as Harry Enfield’s annoying character used to say “Only Me!”
This month I’ll be discussing manual handling, an area very close to my heart, as I have taught it in varying environments for the last few years. I’ve been privileged enough to visit many different work arenas including TV studios, factories, refuse centres, and endless types of office set-ups. Although the people working in these areas would describe their lifting needs as different, it became evident that there were key principles in training that were important to all.
We’ve all heard the old adage ‘bend your knees, keep your back straight’, but this is a rather out dated notion. As we improve our understanding of human mechanics and damage, we see that leverage and spinal curves are more relevant for a healthy lift.
Firstly we’ll look at leverage. If you imagine a seesaw with an even distance to each end from the centre or pivot point it will sit flat and still. If you then move the pivot toward one end it will tip toward the long side, unless something strong holds the short side down. This is leverage. Still with me? Good. Now imagine that your back is that seesaw, and the bottom of your back is the pivot, as you bend forward you create the long lever with you upper back, head and arms. Already your back muscles are holding you up. Now also realise that 2/3rds of your body weight is above this pivot, so your back muscles are holding up an enormous weight without you even picking anything up. To give you a typical scenario for an average male of 90kg (14st 2lb)
2/3rds of 90kg = 60kg
As they bend, the seesaw will look like this:
Low back muscles upper back, arms, head, load
There is a difference of 10 to 1 for the load and an average of 5 to 1 for the 60kg torso. If the load is something relatively light, i.e. 10kg then the total lift is calculated around (10x 10= 100kg) + (60 x 5= 300kg) = 400kg (63st)With these figures we can see how easy it is to damage the low back with very little effort. This why when I teach manual handling I stress the importance of getting the load as close to the body as possible, therefore limiting any levers.
Secondly, spinal curves matter to prevent damage to the discs and muscles of the low back. If the normal low back curve is maintained then the spinal muscles are only supporting the spines posture and not taking part in the lift which will lead to there damage. It will also more likely promote use of the correct leg muscles for the lift itself.
For more information on manual handling or the clinic, to discuss a particular case, or to book an appointment, please call Tristan Hill on 01949 839 238 or e-mail firstname.lastname@example.org. Please feel free to visit www.binghamosteopath.co.uk