Human Locomotion

Six million years ago, our human ancestors preferred to live in trees, using their well-developed arms to move them from branch to branch. When on the ground, these primates would normally walk or run on all fours, quite unlike how we move today. When did all this change? Fossilised footprints found at Laetoli in Tanzania prove conclusively that our human ancestors were walking upright some 4m years ago, using just their hind legs. This was a profound evolutionary development or mutation, showing that we were now ground-loving creatures. The gradual physiological evolution of this new posture saw the skull balanced on the top of the spine, which developed a slight curve, while the hips became broader, the legs longer, the feet now have arches while the big toe is aligned with the rest of the foot (unlike the thumb in the hand). In other words, the adoption of bipedalism required a major anatomical reconfiguration, in terms of the skeleton, the muscle attachments and the posture. It is one of the defining characteristics of the human frame (rather than that of all our other more ape-like relations) and cannot represent a sudden change. In other words, humans are very clearly designed to walk, and broadly speaking that part of our design has remained largely unchanged for some 4m years.

From our evolutionary perspective therefore, walking is normal. Sitting at a desk, on a sofa or in a car for long periods is, by contrast, not what the human body is configured for. As far as our physiology is concerned, such sedentary behaviour is abnormal. Our bodies, like pet dogs, need to be taken out for a walk every day and that’s a habit that needs to be embedded in urban children from the outset. The school walk, rather than the school run, needs to become the social norm, for example.

There are a number of social and cultural factors that seem to militate against a more widespread adoption of walking or cycling for such short and medium distances in towns, rather than taking the car. Some of these have been discussed by Colin Poole’s team during a study compiled by Lancaster University in 2012 for the NICE. These include issues with the safety of local streets, an especial concern for potential cyclists, but also for parents who would otherwise by willing to see their children walking to school each day. But perhaps the major issue is the current image of walking and cycling: urban human locomotion needs to be rebranded as completely normal rather than as an activity for a specialist group of keep fit fanatics.

Certainly there are major town planning issues to be resolved and implemented if the over-dependence on cars in urban areas is to be phased out. Measures include designated cycle paths, well planted streets that are attractive for pedestrians, traffic-calming measures around schools and other urban focii, and a clearly unified network of greenways that consciously encourage human locomotion in all its forms for journeys of differing durations.

The benefits for an urban population of all ages provided by such simple, natural daily exercise can only be reiterated: the savings to the National Health Service on its budget for obesity, Type 2 Diabetes and for cardiovascular problems also make this an attractive economic proposition. Human locomotion is one of the key evolutionary determinants of our health: by making towns more attractive for pedestrians and cyclists we all benefit, not least with cleaner air and less noise pollution. It’s time we reinvented the foot.


References

Health & Social Care Information Centre 2011 Is the Adult Population of England Active Enough?

Poole, CG, 2012 The Understanding Walking & Cycling project (Lancaster University)